Document and Entity Information	9 Months Ended
Document and Entity Information	Jun. 30, 2013	Jul. 30, 2013
Document and Entity Information [Abstract]
Entity Registrant Name	DIGI INTERNATIONAL INC.
Entity Central Index Key	0000854775
Current Fiscal Year End Date	--09-30
Entity Filer Category	Accelerated Filer
Document Type	10-Q
Document Period End Date	Jun. 30, 2013
Document Fiscal Year Focus	2013
Document Fiscal Period Focus	Q3
Amendment Flag	false
Entity Common Stock, Shares Outstanding		25,712,887

Condensed Consolidated Statements of Operations (Unaudited) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Income Statement [Abstract]
Net sales	$ 48,824	$ 47,632	$ 144,012	$ 143,310
Cost of sales	24,104	22,328	69,852	67,793
Gross profit	24,720	25,304	74,160	75,517
Operating expenses:
Sales and marketing	10,372	9,920	31,060	30,359
Research and development	7,606	7,779	22,798	23,764
General and administrative	4,850	4,560	16,356	13,808
Restructuring	0	963	(37)	1,259
Total operating expenses	22,828	23,222	70,177	69,190
Operating income	1,892	2,082	3,983	6,327
Other (expense) income, net:
Interest income	58	71	160	217
Interest expense	0	0	(37)	(15)
Other income, net	(59)	(192)	503	(37)
Total other (expense) income, net	(1)	(121)	626	165
Income before income taxes	1,891	1,961	4,609	6,492
Income tax provision (benefit)	363	(346)	851	1,339
Net income	$ 1,528	$ 2,307	$ 3,758	$ 5,153
Net income per common share:
Basic	$ 0.06	$ 0.09	$ 0.14	$ 0.20
Diluted	$ 0.06	$ 0.09	$ 0.14	$ 0.20
Weighted average common shares:
Basic	25,849	25,770	26,057	25,705
Diluted	26,114	26,043	26,323	26,138

Condensed Consolidated Statements of Comprehensive Income (USD $)
In Thousands, unless otherwise specified

3 Months Ended

9 Months Ended

Jun. 30, 2013

Jun. 30, 2012

Jun. 30, 2013

Jun. 30, 2012

Net income

$ 1,528

$ 2,307

$ 3,758

$ 5,153

Foreign currency translation adjustment

127

(2,533)

(3,252)

(4,455)

Change in net unrealized (loss) gain on investments

(13)

(7)

(72)

Less income tax benefit (provision)

(31)

Reclassification of realized loss included in net income

^[1]

Less income tax benefit

^[2]

(5)

^[2]

Other comprehensive income (loss), net of tax

119

(2,537)

(3,296)

(4,399)

Comprehensive income (loss)

$ 1,647

$ (230)

$ 462

$ 754

[1]	Recorded in Other (expense) income, net in our Condensed Consolidated Statements of Operations.
[2]	Recorded in Income tax provision (benefit) in our Condensed Consolidated Statements of Operations.

Condensed Consolidated Balance Sheets (Unaudited) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2013	Sep. 30, 2012
Current assets:
Cash and cash equivalents	$ 45,892	$ 60,246
Marketable securities	44,806	58,372
Accounts receivable, net	24,969	24,634
Inventories	25,296	24,435
Deferred tax assets	3,151	3,389
Other	5,772	2,493
Total current assets	149,886	173,569
Marketable securities, long-term	13,108	2,016
Property, equipment and improvements, net	14,480	15,157
Identifiable intangible assets, net	11,021	10,629
Goodwill	102,611	86,209
Deferred tax assets	5,232	5,010
Other	528	494
Total assets	296,866	293,084
Current liabilities:
Accounts payable	8,505	6,040
Income taxes payable	0	1,269
Accrued compensation	7,718	5,744
Accrued warranty	1,132	1,021
Other	3,424	4,118
Total current liabilities	20,779	18,192
Income taxes payable	3,284	3,294
Deferred tax liabilities	444	630
Other noncurrent liabilities	97	111
Total liabilities	24,604	22,227
Contingencies (see Note 10)
Stockholders' equity:
Preferred stock, $.01 par value; 2,000,000 shares authorized; none issued and outstanding	0	0
Common stock, $.01 par value; 60,000,000 shares authorized; 30,145,957 and 29,268,788 shares issued	301	293
Additional paid-in capital	210,248	199,495
Retained earnings	114,041	110,283
Accumulated other comprehensive loss	(17,021)	(13,725)
Treasury stock, at cost, 4,384,774 and 3,356,453 shares	(35,307)	(25,489)
Total stockholders' equity	272,262	270,857
Total liabilities and stockholders' equity	$ 296,866	$ 293,084

Condensed Consolidated Balance Sheets (Unaudited) (Parenthetical) (USD $)	Jun. 30, 2013	Sep. 30, 2012
Statement of Financial Position [Abstract]
Preferred stock, par value	$ 0.01	$ 0.01
Preferred stock, shares authorized	2,000,000	2,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	60,000,000	60,000,000
Common stock, shares issued	30,145,957	29,268,788
Treasury stock, shares	4,384,774	3,356,453

Condensed Consolidated Statements of Cash Flows (Unaudited) (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Jun. 30, 2013	Jun. 30, 2012
Operating activities:
Net income	$ 3,758	$ 5,153
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation of property, equipment and improvements	2,551	2,483
Amortization of identifiable intangible assets	3,326	3,537
Stock-based compensation	2,906	2,798
Excess tax benefits from stock-based compensation	(60)	(133)
Deferred income tax benefit	(1,397)	(1,791)
Bad debt/product return provision	616	521
Inventory obsolescence	759	1,080
Restructuring	0	1,259
Other	(109)	(81)
Changes in operating assets and liabilities (net of acquisition)	(4,242)	(5,867)
Net cash provided by operating activities	8,108	8,959
Investing activities:
Purchase of marketable securities	(49,121)	(64,234)
Proceeds from maturities of marketable securities	51,773	45,998
Proceeds from sale of investment	0	135
Acquisition of business, net of cash acquired	12,919	0
Purchase of property, equipment, improvements and certain other intangible assets	(2,415)	(3,003)
Net cash used in investing activities	(12,682)	(21,104)
Financing activities:
Excess tax benefits from stock-based compensation	60	133
Proceeds from stock option plan transactions	1,171	600
Proceeds from employee stock purchase plan transactions	740	811
Purchases of common stock	(10,577)	0
Net cash (used in) provided by financing activities	(8,606)	1,544
Effect of exchange rate changes on cash and cash equivalents	(1,174)	(1,869)
Net decrease in cash and cash equivalents	(14,354)	(12,470)
Cash and cash equivalents, beginning of period	60,246	54,684
Cash and cash equivalents, end of period	45,892	42,214
Cash Flow, Noncash Investing and Financing Activities Disclosure [Abstract]
Issuance of common stock for business acquisition	(6,804)	0
Securities purchased, not settled	$ (250)	$ 0

Basis of Presentation of Unaudited Interim Condensed Consolidated Financial Statements and Significant Accounting Policies	9 Months Ended
	Jun. 30, 2013
Accounting Policies [Abstract]
BASIS OF PRESENTATION OF UNAUDITED INTERIM CONDENSED CONSOLIDATED FINANCIAL STATEMENTS AND SIGNIFICANTACCOUNTING POLICIES	BASIS OF PRESENTATION OF UNAUDITED INTERIM CONDENSED CONSOLIDATED FINANCIAL STATEMENTS AND SIGNIFICANT ACCOUNTING POLICIES Basis of Presentation The interim unaudited condensed consolidated financial statements included in this Form 10-Q have been prepared by Digi International Inc. (the “Company,” “Digi,” “we,” “our,” or “us”) pursuant to the rules and regulations of the United States Securities and Exchange Commission (the “SEC”). Certain information and footnote disclosures, normally included in consolidated financial statements prepared in accordance with accounting principles generally accepted in the United States of America (“U.S. GAAP”), have been condensed or omitted pursuant to such rules and regulations. These condensed consolidated financial statements should be read in conjunction with the consolidated financial statements and related notes thereto, including (but not limited to) the summary of significant accounting policies, presented in our Annual Report on Form 10-K for the year ended September 30, 2012 as filed with the SEC (“2012 Financial Statements”). The condensed consolidated financial statements presented herein reflect, in the opinion of management, all adjustments which consist only of normal, recurring adjustments necessary for a fair statement of the condensed consolidated balance sheets and condensed consolidated statements of operations, comprehensive income and cash flows for the periods presented. The condensed consolidated results of operations for any interim period are not necessarily indicative of results for the full year. The year-end condensed consolidated balance sheet data were derived from our 2012 Consolidated Financial Statements, but do not include all disclosures required by U.S. GAAP. Recently Issued Accounting Pronouncements Adopted In April 2013, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update ("ASU") 2013-07, "Presentation of Financial Statements (Topic 205); Liquidation Basis of Accounting." The objective of this guidance is to clarify when an entity should apply the liquidation basis of accounting and to provide principles for the measurement of assets and liabilities under the liquidation basis of accounting, as well as any required disclosures. The amendments in this standard are effective prospectively for entities that determine liquidation is imminent during annual reporting periods beginning after December 15, 2013, and interim reporting periods therein. Early adoption is permitted. We adopted this guidance in the third quarter of fiscal 2013. Since liquidation is not imminent, the adoption did not have an impact on our consolidated financial statements. In February 2013, the FASB issued ASU 2013-02, "Comprehensive Income (Topic 220); Reporting of Amounts Reclassified Out of Accumulated Other Comprehensive Income." This updated guidance improves the reporting of significant items reclassified out of accumulated other comprehensive income and requires an entity to present, either on the face of the statement where net income is presented or in the notes, separately for each component of comprehensive income, the current period reclassifications out of accumulated other comprehensive income by the respective line items of net income affected by the reclassification. The updated guidance is effective prospectively for reporting periods beginning after December 15, 2012. We adopted this guidance beginning January 1, 2013. Other than requiring additional disclosures that are in the footnotes to the Condensed Statements of Comprehensive Income (Loss), the adoption did not have an effect on our consolidated financial statements. Not Adopted In March 2013, the FASB issued ASU 2013-05, "Foreign Currency Matters (Topic 830); Parent’s Accounting for the Cumulative Translation Adjustment upon Derecognition of Certain Subsidiaries or Groups of Assets within a Foreign Entity or of an Investment in a Foreign Entity." This guidance applies to the release of the cumulative translation adjustment into net income when a parent either sells a part or all of its investment in a foreign entity or no longer holds a controlling financial interest in a subsidiary or group of assets that is a business (other than a sale of in substance real estate or conveyance of oil and gas mineral rights) within a foreign entity. ASU No. 2013-05 is effective prospectively for fiscal years (and interim reporting periods within those years) beginning after December 15, 2013. We will adopt this guidance beginning with our fiscal quarter ending December 31, 2014. We currently are reviewing the provisions of ASU No. 2013-05 but do not expect it to have an effect on our consolidated financial statements as we do not intend to sell any foreign entities for which we hold a controlling financial interest.

Earnings Per Share

9 Months Ended

Jun. 30, 2013

Earnings Per Share [Abstract]

EARNINGS PER SHARE

Basic net income per common share is calculated based on the weighted average number of common shares outstanding during the period. Diluted net income per common share is computed by dividing net income by the weighted average number of common and potentially dilutive common shares outstanding during the period. Potentially dilutive common shares of our stock result from dilutive common stock options, restricted stock units and shares purchased through our employee stock purchase plan.

The following table is a reconciliation of the numerators and denominators in the net income per common share calculations (in thousands, except per common share data):



	Three months ended June 30,				Nine months ended June 30,
	2013		2012		2013		2012
Numerator:
Net income	$	1,528	$	2,307	$	3,758	$	5,153
Denominator:
Denominator for basic net income per common share — weighted average shares outstanding	25,849		25,770		26,057		25,705
Effect of dilutive securities:
Employee stock options and restricted stock units	265		273		266		433
Denominator for diluted net income per common share — adjusted weighted average shares	26,114		26,043		26,323		26,138
Net income per common share, basic	$	0.06	$	0.09	$	0.14	$	0.20
Net income per common share, diluted	$	0.06	$	0.09	$	0.14	$	0.20

Because their effect would be anti-dilutive, certain potentially dilutive shares related to stock options to purchase common shares were not included in the above computation of diluted earnings per common share. This is because the options’ exercise prices were greater than the average market price of our common shares. For the three and nine month periods ended June 30, 2013, there were 1,516,657 and 2,194,757 potentially dilutive shares related to such stock options. For the three and nine month periods ended June 30, 2012, there were 3,254,285 and 2,019,690 potentially dilutive shares related to such stock options.

Acquisition

9 Months Ended

Jun. 30, 2013

Business Combinations [Abstract]

ACQUISITION

Etherios, Inc.

On October 31, 2012, we acquired Etherios, Inc. ("Etherios"). The total purchase price of $20.5 million included $13.7 million in cash (excluding cash acquired of $0.8 million) and $6.8 million represented by 715,571 shares of our common stock. The common stock issued was valued at $9.508 per common share.

Cash in the amount of $2.35 million was deposited to an escrow fund with a third party agent. Of the $2.35 million escrow, $0.3 million related to a holdback amount pending final determination of the unpaid debt and working capital as shown on the closing balance sheet. This holdback amount was paid in February 2013 as there were no changes to the closing balance sheet. An additional $2.05 million is held in escrow for a period not to exceed eighteen months from the date of closing to satisfy possible claims that may arise pursuant to specific representation and warranty sections of the stock purchase agreement. The escrowed amounts have been included in the determination of the purchase consideration on the date of acquisition as management expects that the representation and warranty matters is determinable beyond a reasonable doubt.

Costs related to the acquisition, which include legal, accounting and valuation fees, in the amount of $0.2 million have been charged directly to operations and are included in general and administrative expense in our consolidated statement of operations for the nine months ended June 30, 2013.

The purchase price was allocated to the estimated fair value of assets acquired and liabilities assumed. The purchase price allocation resulted in the recognition of $17.1 million of goodwill. We believe that the acquisition resulted in the recognition of goodwill primarily because Etherios is a salesforce.com Platinum Partner and experienced in end user implementation of the

3. ACQUISITION (CONTINUED)

Salesforce Service Cloud. Although we believe the relationship with salesforce.com is important to us, it is not an exclusive relationship and requires Etherios to compete with others for business opportunities. Accordingly, we have determined that this relationship cannot be valued as a separate intangible asset of Etherios and as a result is a component of goodwill.

As salesforce.com has signaled its intent for the Service Cloud to be used as a means to monitor machines, we also believe that the acquisition of Etherios will likely further enhance our solutions offerings and provide another channel for net sales of our networking products.

Etherios' operating results are included in our consolidated results of operations from the date of acquisition. The consolidated balance sheet as of June 30, 2013 reflects the allocation of the purchase price to the assets acquired and liabilities assumed based on their estimated fair values at the date of acquisition.

The Etherios acquisition has been accounted for using the acquisition method of accounting which requires, among other things, that most assets acquired and liabilities assumed pursuant to the stock purchase agreement be recognized at fair value as of the acquisition date. Our estimate for goodwill is not yet finalized and is subject to change. We expect to finalize the purchase price allocation by the end of fiscal 2013.

The table below sets forth the preliminary purchase price allocation (in thousands):



Cash, including cash in escrow	$	13,696
Common stock	6,804
Total	$	20,500

Fair value of net tangible assets acquired	$	1,367
Identifiable intangible assets:
Existing customer relationships	1,400
Non-compete agreements	1,100
Trade name	440
Order backlog	360
Goodwill	17,120
Deferred tax liabilities related to identifiable intangibles	(1,287		)
Total	$	20,500

The weighted average useful life for all the identifiable intangibles listed above is 5.7 years. For purposes of determining fair value, the existing customer relationships identified above are assumed to have useful lives ranging between six to eight years, non-compete agreements are assumed to have useful lives of five years, the trade name is assumed to have a useful life of seven years, and the order backlog is assumed to have a useful life of one year. Useful lives for identifiable intangible assets are estimated at the time of acquisition based on the periods of time from which we expect to derive benefits from the identifiable intangible assets. The identifiable intangible assets are amortized using the straight-line method which reflects the pattern in which the asset is expected to be consumed.

We have determined that the Etherios acquisition is not material to our consolidated results of operations or financial position. Pro forma financial information therefore is not presented.

Selected Balance Sheet Data

9 Months Ended

Jun. 30, 2013

Selected Balance Sheet Data [Abstract]

SELECTED BALANCE SHEET DATA

(in thousands)



	June 30, 2013		September 30, 2012
Accounts receivable, net:
Accounts receivable	$	25,343	$	24,929
Less allowance for doubtful accounts	374		295
	$	24,969	$	24,634
Inventories:
Raw materials	$	20,159	$	18,159
Work in process	411		428
Finished goods	4,726		5,848
	$	25,296	$	24,435

Inventories are stated at the lower of cost or market value, with cost determined using the first-in, first-out method.

Marketable Securities

9 Months Ended

Jun. 30, 2013

Marketable Securities [Abstract]

MARKETABLE SECURITIES

Our marketable securities consist of certificates of deposit, commercial paper, corporate bonds and government municipal bonds. We analyze our available-for-sale marketable securities for impairment on an ongoing basis. When we perform this analysis, we consider factors such as the length of time and extent to which the securities have been in an unrealized loss position and the trend of any unrealized losses. We also consider whether an unrealized loss is a temporary loss or an other-than-temporary loss based on factors such as: (a) whether we have the intent to sell the security, (b) whether it is more likely than not that we will be required to sell the security before its anticipated recovery, or (c) permanent impairment due to bankruptcy or insolvency.

In order to estimate the fair value for each security in our investment portfolio, we obtain quoted market prices and trading activity for each security where available. We obtain relevant information from our investment advisor and, if warranted, also may review the financial solvency of certain security issuers. As of June 30, 2013, 62 of our 71 securities that we are holding were trading below our amortized cost basis. We determined each decline in value to be temporary based upon the above described factors. We expect to realize the fair value of these securities, plus accrued interest, either at the time of maturity or when the security is sold. All of our current holdings are classified as available-for-sale marketable securities and are recorded at fair value on our consolidated balance sheet with the unrealized gains and losses recorded in accumulated other comprehensive loss. All of our current marketable securities will mature in less than one year and our non-current marketable securities will mature in less than 3 years. At June 30, 2013 our marketable securities were (in thousands):



	Amortized Cost (1)		Unrealized Gains		Unrealized Losses (2)			Fair Value (1)
Current marketable securities:
Corporate bonds	$	34,163	$	6	$	(47	)	$	34,122
Certificates of deposit	3,004		—		(3		)	3,001
Government municipal bonds	7,682		2		(1		)	7,683
Current marketable securities	44,849		8		(51		)	44,806
Non-current marketable securities:
Corporate bonds	2,030		—		(5		)	2,025
Certificates of deposit	8,002		—		(34		)	7,968
Government municipal bonds	3,117		—		(2		)	3,115
Non-current marketable securities	13,149		—		(41		)	13,108
Total marketable securities	$	57,998	$	8	$	(92	)	$	57,914


(1)	Included in amortized cost and fair value is purchased and accrued interest of $388.


(2)	The aggregate related fair value of securities with unrealized losses as of June 30, 2013 was $47,140. These investments have been in an unrealized loss position for less than twelve months.

5. MARKETABLE SECURITIES (CONTINUED)

At September 30, 2012 our marketable securities were (in thousands):



	Amortized Cost (1)		Unrealized Gains		Unrealized Losses (2)			Fair Value (1)
Current marketable securities:
Corporate bonds	$	39,306	$	14	$	(19	)	$	39,301
Commercial paper	2,000		—		—			2,000
Certificates of deposit	7,262		—		(4		)	7,258
Government municipal bonds	9,814		1		(2		)	9,813
Current marketable securities	58,382		15		(25		)	58,372
Non-current marketable securities:
Corporate bonds	2,019		—		(3		)	2,016
Total marketable securities	$	60,401	$	15	$	(28	)	$	60,388


(1)	Included in amortized cost and fair value is purchased and accrued interest of $485.


(2)	The aggregate related fair value of securities with unrealized losses as of September 30, 2012 was $34,503. These investments have been in an unrealized loss position for less than twelve months.

Fair Value Measurements

9 Months Ended

Jun. 30, 2013

Fair Value Disclosures [Abstract]

FAIR VALUE MEASUREMENTS

Fair value is defined as the amount that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants as of the measurement date. This standard also establishes a hierarchy for inputs used in measuring fair value. This standard maximizes the use of observable inputs and minimizes the use of unobservable inputs by requiring that the most observable inputs be used when available. Observable inputs are inputs market participants would use in valuing the asset or liability based on market data obtained from independent sources. Unobservable inputs are inputs that reflect our assumptions about the factors market participants would use in valuing the asset or liability based upon the best information available in the circumstances. The categorization of financial assets and liabilities within the valuation hierarchy is based upon the lowest level of input that is significant to the fair value measurement.

The hierarchy is broken down into the following three levels:


•	Level 1 — Inputs are quoted prices in active markets for identical assets or liabilities.


•	Level 2 — Inputs include quoted prices for similar assets or liabilities in active markets, quoted prices for identical or similar assets or liabilities in markets that are not active, and inputs (other than quoted prices) that are observable for the asset or liability, either directly or indirectly.

•

Level 3 — Inputs are unobservable for the asset or liability and their fair values are determined using pricing models, discounted cash flow methodologies or similar techniques and at least one significant model assumption or input is unobservable. Level 3 may also include certain investment securities for which there is limited market activity or a decrease in the observability of market pricing for the investments, such that the determination of fair value requires significant judgment or estimation.

Fair value is applied to financial assets such as our marketable securities, which are classified and accounted for as available-for-sale. These items are stated at fair value at each reporting period using the above guidance.

6. FAIR VALUE MEASUREMENTS (CONTINUED)

The following tables provide information by level for financial assets that are measured at fair value on a recurring basis (in thousands):



			Fair Value Measurements at June 30, 2013 using:
	Total carrying value at June 30, 2013		Quoted price in active markets (Level 1)		Significant other observable inputs (Level 2)		Significant unobservable inputs (Level 3)
Cash equivalents:
Money market	$	13,894	$	13,894	$	—	$	—
Available-for-sale marketable securities:
Corporate bonds	36,147		—		36,147		—
Certificates of deposit	10,969		—		10,969		—
Government municipal bonds	10,798		—		10,798		—
Total cash equivalents and marketable securities measured at fair value	$	71,808	$	13,894	$	57,914	$	—



			Fair Value Measurements at September 30, 2012 using:
	Total carrying value at September 30, 2012		Quoted price in active markets (Level 1)		Significant other observable inputs (Level 2)		Significant unobservable inputs (Level 3)
Cash equivalents:
Money market	$	28,355	$	28,355	$	—	$	—
Available-for-sale marketable securities:
Corporate bonds	41,317		—		41,317		—
Commercial paper	2,000		—		2,000		—
Certificates of deposit	7,258		—		7,258		—
Government municipal bonds	9,813		—		9,813		—
Total cash equivalents and marketable securities measured at fair value	$	88,743	$	28,355	$	60,388	$	—

Cash equivalents are measured at fair value using quoted market prices in active markets for identical assets and are therefore classified as Level 1 assets. We value our Level 2 assets using inputs that are based on market indices of similar assets within an active market. There were no transfers into or out of our Level 2 financial assets during the nine months ended June 30, 2013.

We had no financial assets valued with Level 3 inputs as of June 30, 2013 nor did we purchase or sell any Level 3 financial assets during the nine months ended June 30, 2013.

The use of different assumptions, applying different judgment to matters that inherently are subjective and changes in future market conditions could result in different estimates of fair value of our securities, currently and in the future. If market conditions deteriorate, we may incur impairment charges for securities in our investment portfolio.

Goodwill and other Identifiable Intangible Assets

9 Months Ended

Jun. 30, 2013

Goodwill and Intangible Assets Disclosure [Abstract]

GOODWILL AND OTHER IDENTIFIABLE INTANGIBLE ASSETS

Amortizable identifiable intangible assets were (in thousands):



	June 30, 2013							September 30, 2012
	Gross carrying amount		Accum. amort.			Net		Gross carrying amount		Accum. amort.			Net
Purchased and core technology	$	46,248	$	(44,193	)	$	2,055	$	46,597	$	(43,639	)	$	2,958
License agreements	2,840		(2,737		)	103		2,840		(2,682		)	158
Patents and trademarks	11,924		(9,302		)	2,622		10,943		(8,469		)	2,474
Customer maintenance contracts	700		(700		)	—		700		(700		)	—
Customer relationships	18,699		(13,531		)	5,168		17,504		(12,465		)	5,039
Non-compete agreements	2,131		(1,178		)	953		1,045		(1,045		)	—
Order backlog	360		(240		)	120		—		—			—
Total	$	82,902	$	(71,881	)	$	11,021	$	79,629	$	(69,000	)	$	10,629

Amortization expense was $1.1 million for each of the three month periods ended June 30, 2013 and 2012. Amortization was $3.3 million and $3.5 million for the nine month periods ended June 30, 2013 and 2012, respectively. Amortization expense is recorded on our consolidated statements of operations within cost of sales and in general and administrative expense. Estimated amortization expense related to identifiable intangible assets for the remainder of fiscal 2013 and the five succeeding fiscal years is (in thousands):



2013 (three months)	$	1,093
2014	3,809
2015	2,805
2016	1,466
2017	706
2018	482

The changes in the carrying amount of goodwill are (in thousands):



	Nine months ended June 30,
	2013			2012
Beginning balance, October 1	$	86,209		$	86,012
Acquisition of Etherios, Inc.	17,120			—
Foreign currency translation adjustment	(718		)	(468		)
Ending balance, June 30	$	102,611		$	85,544

The goodwill related to the acquisition of Etherios is not tax deductible. Etherios is included in our single reporting segment for purposes of goodwill impairment testing.

Goodwill is tested for impairment on an annual basis as of June 30, or more frequently if events or circumstances occur which could indicate impairment. The calculation of goodwill impairment requires us to make assumptions about the fair value of our one reporting unit, which historically has been approximated by using our market capitalization plus a control premium. Control premium assumptions require judgment and actual results may differ from assumed or estimated amounts.

At June 30, 2013, we had approximately $102.6 million of goodwill on our balance sheet. Our test for potential goodwill impairment is a two-step approach. We estimate the fair value for our one reporting unit by comparing its fair value (market capitalization plus control premium) to our carrying value. If the carrying value of the reporting unit exceeds its estimated fair value, the second step of the goodwill impairment analysis requires us to measure the amount of the impairment loss. An impairment loss is calculated by comparing the implied fair value of the goodwill to its carrying amount. To calculate the implied fair value of goodwill, the fair value of the reporting unit's assets and liabilities, excluding goodwill, is estimated. The

7. GOODWILL AND OTHER IDENTIFIABLE INTANGIBLE ASSETS (CONTINUED)

excess of the fair value of the reporting unit over the amount assigned to its assets and liabilities, excluding goodwill, is the implied fair value of the reporting unit's goodwill.

In June 2012 we performed a control premium study to determine the appropriate control premium to include in the calculation of fair value, using a third party valuation firm to assist us in performing the control premium analysis. In order to estimate the range of control premiums appropriate for us, three methodologies were used, including: (1) analysis of individual transactions within our industry; (2) analysis of industry-wide data, and (3) analysis of global transaction data. The control premium analysis resulted in a range of control premium of 30 percent to 45 percent. We reviewed the data provided and estimated that a 40 percent control premium best represents the amount an investor would likely pay, over and above market capitalization, in order to obtain a controlling interest given the economic conditions at that time. Based on our industry knowledge and recent discussions with our third party valuation firm, we concluded that the control premium study that was performed in conjunction with our annual goodwill impairment assessment at June 30, 2012 remains valid and that the 40 percent control premium used in our prior year's assessment continues to best represent the amount an investor likely would pay, over and above market capitalization, in order to obtain a controlling interest given the current economic conditions. At June 30, 2013, our market capitalization was $241.4 million compared to our carrying value of $272.3 million. Our market capitalization plus our estimated control premium of 40% resulted in a fair value in excess of our carrying value by a margin of 24%. As a result, no impairment was indicated and we were not required to complete the second step of the goodwill impairment analysis. No goodwill impairment charges were recorded.

If our stock price or control premium declines, the first step of our goodwill impairment analysis may fail. We have defined the criteria that could result in additional interim goodwill impairment testing. We would perform the second step of the impairment testing if our stock price fell below defined thresholds for a significant period of time, or if our control premium significantly decreased. Events or circumstances may occur that could negatively impact our stock price, including changes in our anticipated revenues and profits and our ability to execute on our strategies. In addition, our control premium could decline due to changes in economic conditions in the technology industry, in the financial markets or more generally. An impairment could have a material effect on our consolidated balance sheet and results of operations.

Income Taxes

9 Months Ended

Jun. 30, 2013

Income Tax Disclosure [Abstract]

INCOME TAXES

Income taxes have been provided at an overall effective rate of 18.5% and 20.6% for the nine month periods ended June 30, 2013 and 2012, respectively. The overall effective tax rate includes the discrete items mentioned in the following paragraphs. Our effective tax rate will vary based on a variety of factors, including overall profitability, the geographical mix of income before taxes and related statutory tax rate in each jurisdiction, and discrete events, such as settlements of audits.

In the third quarter of fiscal 2013, we recorded a discrete tax benefit of $0.1 million for the release of income tax reserves due to the expiration of the statutes of limitation for U.S. Federal income tax for fiscal 2009. In addition, we recorded adjustments of estimates in connection with the filing of tax returns for the U.S. and a foreign tax jurisdiction. In the second quarter of fiscal 2013, we recorded a discrete tax benefit of $0.4 million resulting from the enactment of legislation on January 2, 2013 extending the research and development tax credit for the last three quarters of fiscal 2012. In the first quarter of fiscal 2013, we recorded a discrete tax benefit of $0.1 million for the release of income tax reserves due to the expiration of the statutes of limitation from various U.S. and foreign tax jurisdictions. These discrete tax benefits reduced our effective tax rate by 13.7 percentage points for the nine month period ended June 30, 2013. The effective tax rate for the first nine months of fiscal 2013, before consideration of the impact of the discrete tax benefit, was lower than the Federal statutory rate primarily due to the current year benefit of the federal research and development tax credit.

In the third quarter of fiscal 2012, we recorded a discrete tax benefit of $1.1 million for additional research and development tax credits identified for fiscal years ended September 30, 2009, 2010 and 2011. In the first quarter of fiscal 2012, we recorded a discrete tax benefit of $0.1 million for the release of income tax reserves due to the expiration of statutes of limitation from various U.S. tax jurisdictions. These discrete tax benefits reduced our effective tax rate by 18.6 percentage points for the nine month period ended June 30, 2012. The effective tax rate for the first nine months of fiscal 2012, before consideration of the impact of the discrete tax benefit, was higher than the Federal statutory rate primarily due to additions of certain reserves for unrecognized tax benefits and an adjustment for foreign income taxed at the U.S. rate, which was partially offset by adjustments in domestic tax benefits.

8. INCOME TAXES (CONTINUED)

A reconciliation of the beginning and ending amount of unrecognized tax benefits is (in thousands):




Unrecognized tax benefits as of September 30, 2012	$	2,720
Increases related to:
Prior year income tax positions	202
Decreases related to:
Expiration of statute of limitations	(191		)
Unrecognized tax benefits as of June 30, 2013	$	2,731

The total amount of unrecognized tax benefits that, if recognized, would affect our effective tax rate is $2.7 million. We expect that it is reasonably possible that the total amounts of unrecognized tax benefits will increase approximately $0.4 million over the next 12 months due to increases in current year reserves, partially offset by a release of reserves due to the expiration of the statute of limitations.

We recognize interest and penalties related to income tax matters in income tax expense. During both the nine month periods ended June 30, 2013 and 2012, there were insignificant amounts of interest and penalties related to income tax matters in income tax expense. We had accrued interest and penalties related to unrecognized tax benefits at both June 30, 2013 and September 30, 2012 of $0.6 million . Our long-term income taxes payable on our condensed consolidated balance sheets includes these accrued interest and penalties in addition to the unrecognized tax benefits in the table above.

At June 30, 2013, we had approximately $24.5 million of accumulated undistributed foreign earnings, for which we have not accrued additional U.S. tax. Our policy is to reinvest earnings of our foreign subsidiaries indefinitely to fund current operations and provide for future international expansion opportunities, and only repatriate earnings to the extent that U.S. taxes have already been recorded. Although we have no current need to do so, if we change our assertion that we do not intend to repatriate additional undistributed foreign earnings for cash requirements in the United States, we would have to accrue applicable taxes. The amount of any taxes and the application of any tax credits would be determined based on the income tax laws at the time of such repatriation. Under current tax laws, we estimate the unrecognized deferred tax liability to be in the range of $2.5 million to $3.5 million which could have a material impact on our current consolidated balance sheet, results of operations and cash flows.

We operate in multiple tax jurisdictions both in the U.S. and outside of the U.S. Accordingly, we must determine the appropriate allocation of income to each of these jurisdictions. This determination requires us to make several estimates and assumptions. Tax audits associated with the allocation of this income, and other complex issues, may require an extended period of time to resolve and may result in adjustments to our income tax balances in those years that are material to our consolidated balance sheet and results of operations. We are no longer subject to income tax examination for tax years prior to fiscal 2010, except for certain refund claims applicable to fiscal 2009, in the case of U.S. federal tax authorities and prior to fiscal 2008 for non-U.S. income tax authorities. For state taxing authorities, most notably in Minnesota, California and Texas, we are no longer subject to income tax examination for tax years generally before fiscal 2008.

Product Warranty Obligation

9 Months Ended

Jun. 30, 2013

Product Warranties Disclosures [Abstract]

PRODUCT WARRANTY OBLIGATION

In general, we warrant our products to be free from defects in material and workmanship under normal use and service. The warranty periods generally range from one to five years. We typically have the option to either repair or replace products we deem defective with regard to material or workmanship. Estimated warranty costs are accrued in the period that the related revenue is recognized based upon an estimated average per unit repair or replacement cost applied to the estimated number of units under warranty. These estimates are based upon historical warranty incidents and are evaluated on an ongoing basis to ensure the adequacy of the warranty accrual.

9. PRODUCT WARRANTY OBLIGATION (CONTINUED)

The following table summarizes the activity associated with the product warranty accrual (in thousands) and is included on our Condensed Consolidated Balance Sheets as its own line item within current liabilities:



	Balance at		Warranties		Settlements			Balance at
Period	April 1		issued		made			June 30
Three months ended June 30, 2013	$	925	$	331	$	(124	)	$	1,132
Three months ended June 30, 2012	$	981	$	132	$	(115	)	$	998

	Balance at		Warranties		Settlements			Balance at
Period	October 1		issued		made			June 30
Nine months ended June 30, 2013	$	1,021	$	484	$	(373	)	$	1,132
Nine months ended June 30, 2012	$	941	$	497	$	(440	)	$	998

We are not responsible for, and do not warrant that, custom software versions, created by original equipment manufacturer (OEM) customers based upon our software source code, will function in a particular way, will conform to any specifications or are fit for any particular purpose. Further, we do not indemnify these customers from any third-party liability as it relates to or arises from any customization or modifications made by the OEM customer.

Contingencies	9 Months Ended
Contingencies	Jun. 30, 2013
Commitments and Contingencies Disclosure [Abstract]
CONTINGENCIES	CONTINGENCIES Patent Infringement Lawsuits On May 29, 2012, U.S. Ethernet Innovations, LLC ("USEI") filed a patent infringement lawsuit against us in federal court in the Eastern District of Texas. The lawsuit included allegations against us and one other company pertaining to the infringement of four patents related to Ethernet technology. On April 22, 2013, we announced the settlement of this patent infringement lawsuit for $1.5 million, which was recorded in general and administrative expense on our Condensed Consolidated Statement of Operations during the second quarter of fiscal 2013. The settlement was paid during the third quarter of fiscal 2013. The settlement fully resolves the claims by USEI with no future payment obligations. Net of taxes, the settlement was $1.0 million and therefore reduced earnings per diluted share for the second quarter of fiscal 2013 by approximately $0.04. On May 11, 2010, SIPCO, LLC filed a complaint naming us as a defendant in federal court in the Eastern District of Texas. This claim subsequently was moved to the Northern District of Georgia. The complaint included allegations against us and five other companies pertaining to the infringement of SIPCO's patents by wireless mesh networking and multi-port networking products. On October 23, 2012, we settled the lawsuit for a payment of $500,000, which was recorded in general and administrative expense on our Condensed Consolidated Statement of Operations during the fourth quarter of fiscal 2012, and we entered into a royalty-bearing license agreement for future sales of licensed products sold during the term of the agreement through 2018. We do not expect this license agreement to have a material impact on our consolidated financial statements in the future. In addition to the matters discussed above, in the normal course of business, we are subject to various claims and litigation. There can be no assurance that any claims by third parties, if proven to have merit, will not materially adversely affect our business, liquidity or financial condition. With the exception of certain capitalized legal costs related to patents and trademarks, we expense our legal costs as incurred and record them in general and administrative expense.

Restructuring	9 Months Ended
Restructuring	Jun. 30, 2013
Restructuring and Related Activities [Abstract]
RESTRUCTURING	RESTRUCTURING U.S. Restructuring On April 26, 2012, we announced our intention to restructure certain of our operations. We recorded $1.0 million of restructuring charges on a pre-tax basis. The restructuring related primarily to changes being implemented to focus on a shift in our business to more aggressively sell end-to-end M2M solutions. As a result of this restructuring, we eliminated employment positions in our work force of 30 employees at a cost of $0.6 million for severance and have moved to hire new employees or re-assign existing employees into newly created positions. We also expected to incur expenses from vacating facilities in Davis, California and Huntington Beach, California at a cost of approximately $0.4 million. The payments associated with these charges and all the actions associated with the restructuring were completed during the second quarter of fiscal 2013.

Basis of Presentation of Unaudited Interim Condensed Consolidated Financial Statements and Significant Accounting Policies (Policies)	9 Months Ended
	Jun. 30, 2013
Accounting Policies [Abstract]
Recently Issued Accounting Pronouncements	In April 2013, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update ("ASU") 2013-07, "Presentation of Financial Statements (Topic 205); Liquidation Basis of Accounting." The objective of this guidance is to clarify when an entity should apply the liquidation basis of accounting and to provide principles for the measurement of assets and liabilities under the liquidation basis of accounting, as well as any required disclosures. The amendments in this standard are effective prospectively for entities that determine liquidation is imminent during annual reporting periods beginning after December 15, 2013, and interim reporting periods therein. Early adoption is permitted. We adopted this guidance in the third quarter of fiscal 2013. Since liquidation is not imminent, the adoption did not have an impact on our consolidated financial statements. In February 2013, the FASB issued ASU 2013-02, "Comprehensive Income (Topic 220); Reporting of Amounts Reclassified Out of Accumulated Other Comprehensive Income." This updated guidance improves the reporting of significant items reclassified out of accumulated other comprehensive income and requires an entity to present, either on the face of the statement where net income is presented or in the notes, separately for each component of comprehensive income, the current period reclassifications out of accumulated other comprehensive income by the respective line items of net income affected by the reclassification. The updated guidance is effective prospectively for reporting periods beginning after December 15, 2012. We adopted this guidance beginning January 1, 2013. Other than requiring additional disclosures that are in the footnotes to the Condensed Statements of Comprehensive Income (Loss), the adoption did not have an effect on our consolidated financial statements.

Earnings Per Share (Tables)

9 Months Ended

Jun. 30, 2013

Earnings Per Share [Abstract]

Schedule of Calculation of Numerator and Denominator in Earnings Per Share

The following table is a reconciliation of the numerators and denominators in the net income per common share calculations (in thousands, except per common share data):



	Three months ended June 30,				Nine months ended June 30,
	2013		2012		2013		2012
Numerator:
Net income	$	1,528	$	2,307	$	3,758	$	5,153
Denominator:
Denominator for basic net income per common share — weighted average shares outstanding	25,849		25,770		26,057		25,705
Effect of dilutive securities:
Employee stock options and restricted stock units	265		273		266		433
Denominator for diluted net income per common share — adjusted weighted average shares	26,114		26,043		26,323		26,138
Net income per common share, basic	$	0.06	$	0.09	$	0.14	$	0.20
Net income per common share, diluted	$	0.06	$	0.09	$	0.14	$	0.20

Acquisition (Tables)

9 Months Ended

Jun. 30, 2013

Business Combinations [Abstract]

Schedule of Purchase Price Allocation

The table below sets forth the preliminary purchase price allocation (in thousands):



Cash, including cash in escrow	$	13,696
Common stock	6,804
Total	$	20,500

Fair value of net tangible assets acquired	$	1,367
Identifiable intangible assets:
Existing customer relationships	1,400
Non-compete agreements	1,100
Trade name	440
Order backlog	360
Goodwill	17,120
Deferred tax liabilities related to identifiable intangibles	(1,287		)
Total	$	20,500

Selected Balance Sheet Data (Tables)

9 Months Ended

Jun. 30, 2013

Selected Balance Sheet Data [Abstract]

Schedule of Selected Balance Sheet Data



	June 30, 2013		September 30, 2012
Accounts receivable, net:
Accounts receivable	$	25,343	$	24,929
Less allowance for doubtful accounts	374		295
	$	24,969	$	24,634
Inventories:
Raw materials	$	20,159	$	18,159
Work in process	411		428
Finished goods	4,726		5,848
	$	25,296	$	24,435

Marketable Securities (Tables)

9 Months Ended

Jun. 30, 2013

Marketable Securities [Abstract]

Schedule of Marketable Securities

At June 30, 2013 our marketable securities were (in thousands):



	Amortized Cost (1)		Unrealized Gains		Unrealized Losses (2)			Fair Value (1)
Current marketable securities:
Corporate bonds	$	34,163	$	6	$	(47	)	$	34,122
Certificates of deposit	3,004		—		(3		)	3,001
Government municipal bonds	7,682		2		(1		)	7,683
Current marketable securities	44,849		8		(51		)	44,806
Non-current marketable securities:
Corporate bonds	2,030		—		(5		)	2,025
Certificates of deposit	8,002		—		(34		)	7,968
Government municipal bonds	3,117		—		(2		)	3,115
Non-current marketable securities	13,149		—		(41		)	13,108
Total marketable securities	$	57,998	$	8	$	(92	)	$	57,914


(1)	Included in amortized cost and fair value is purchased and accrued interest of $388.


(2)	The aggregate related fair value of securities with unrealized losses as of June 30, 2013 was $47,140. These investments have been in an unrealized loss position for less than twelve months.

5. MARKETABLE SECURITIES (CONTINUED)

At September 30, 2012 our marketable securities were (in thousands):



	Amortized Cost (1)		Unrealized Gains		Unrealized Losses (2)			Fair Value (1)
Current marketable securities:
Corporate bonds	$	39,306	$	14	$	(19	)	$	39,301
Commercial paper	2,000		—		—			2,000
Certificates of deposit	7,262		—		(4		)	7,258
Government municipal bonds	9,814		1		(2		)	9,813
Current marketable securities	58,382		15		(25		)	58,372
Non-current marketable securities:
Corporate bonds	2,019		—		(3		)	2,016
Total marketable securities	$	60,401	$	15	$	(28	)	$	60,388


(1)	Included in amortized cost and fair value is purchased and accrued interest of $485.


(2)	The aggregate related fair value of securities with unrealized losses as of September 30, 2012 was $34,503. These investments have been in an unrealized loss position for less than twelve months.

Fair Value Measurements (Tables)

9 Months Ended

Jun. 30, 2013

Fair Value Disclosures [Abstract]

Fair Value of Assets Measured on Recurring Basis

The following tables provide information by level for financial assets that are measured at fair value on a recurring basis (in thousands):



			Fair Value Measurements at June 30, 2013 using:
	Total carrying value at June 30, 2013		Quoted price in active markets (Level 1)		Significant other observable inputs (Level 2)		Significant unobservable inputs (Level 3)
Cash equivalents:
Money market	$	13,894	$	13,894	$	—	$	—
Available-for-sale marketable securities:
Corporate bonds	36,147		—		36,147		—
Certificates of deposit	10,969		—		10,969		—
Government municipal bonds	10,798		—		10,798		—
Total cash equivalents and marketable securities measured at fair value	$	71,808	$	13,894	$	57,914	$	—



			Fair Value Measurements at September 30, 2012 using:
	Total carrying value at September 30, 2012		Quoted price in active markets (Level 1)		Significant other observable inputs (Level 2)		Significant unobservable inputs (Level 3)
Cash equivalents:
Money market	$	28,355	$	28,355	$	—	$	—
Available-for-sale marketable securities:
Corporate bonds	41,317		—		41,317		—
Commercial paper	2,000		—		2,000		—
Certificates of deposit	7,258		—		7,258		—
Government municipal bonds	9,813		—		9,813		—
Total cash equivalents and marketable securities measured at fair value	$	88,743	$	28,355	$	60,388	$	—

Goodwill and other Identifiable Intangible Assets (Tables)

9 Months Ended

Jun. 30, 2013

Goodwill and Intangible Assets Disclosure [Abstract]

Schedule of Amortizable Identifiable Intangible Assets

Amortizable identifiable intangible assets were (in thousands):



	June 30, 2013							September 30, 2012
	Gross carrying amount		Accum. amort.			Net		Gross carrying amount		Accum. amort.			Net
Purchased and core technology	$	46,248	$	(44,193	)	$	2,055	$	46,597	$	(43,639	)	$	2,958
License agreements	2,840		(2,737		)	103		2,840		(2,682		)	158
Patents and trademarks	11,924		(9,302		)	2,622		10,943		(8,469		)	2,474
Customer maintenance contracts	700		(700		)	—		700		(700		)	—
Customer relationships	18,699		(13,531		)	5,168		17,504		(12,465		)	5,039
Non-compete agreements	2,131		(1,178		)	953		1,045		(1,045		)	—
Order backlog	360		(240		)	120		—		—			—
Total	$	82,902	$	(71,881	)	$	11,021	$	79,629	$	(69,000	)	$	10,629

Schedule of Estimated Amortization Expense Related to Identifiable Intangible Assets

Estimated amortization expense related to identifiable intangible assets for the remainder of fiscal 2013 and the five succeeding fiscal years is (in thousands):



2013 (three months)	$	1,093
2014	3,809
2015	2,805
2016	1,466
2017	706
2018	482

Schedule of Changes in Carrying Amount of Goodwill

The changes in the carrying amount of goodwill are (in thousands):



	Nine months ended June 30,
	2013			2012
Beginning balance, October 1	$	86,209		$	86,012
Acquisition of Etherios, Inc.	17,120			—
Foreign currency translation adjustment	(718		)	(468		)
Ending balance, June 30	$	102,611		$	85,544

Income Taxes (Tables)

9 Months Ended

Jun. 30, 2013

Income Tax Disclosure [Abstract]

Schedule of Unrecognized Tax Benefits

A reconciliation of the beginning and ending amount of unrecognized tax benefits is (in thousands):




Unrecognized tax benefits as of September 30, 2012	$	2,720
Increases related to:
Prior year income tax positions	202
Decreases related to:
Expiration of statute of limitations	(191		)
Unrecognized tax benefits as of June 30, 2013	$	2,731

Product Warranty Obligation (Tables)

9 Months Ended

Jun. 30, 2013

Product Warranties Disclosures [Abstract]

Schedule of Product Warranty Accrual



	Balance at		Warranties		Settlements			Balance at
Period	April 1		issued		made			June 30
Three months ended June 30, 2013	$	925	$	331	$	(124	)	$	1,132
Three months ended June 30, 2012	$	981	$	132	$	(115	)	$	998

	Balance at		Warranties		Settlements			Balance at
Period	October 1		issued		made			June 30
Nine months ended June 30, 2013	$	1,021	$	484	$	(373	)	$	1,132
Nine months ended June 30, 2012	$	941	$	497	$	(440	)	$	998

Earnings Per Share (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Earnings Per Share [Abstract]
Net income	$ 1,528	$ 2,307	$ 3,758	$ 5,153
Denominator for basic net income per common share — weighted average shares outstanding	25,849,000	25,770,000	26,057,000	25,705,000
Effect of dilutive securities [Abstract]
Employee stock options and restricted stock units	265,000	273,000	266,000	433,000
Denominator for diluted net income per common share — adjusted weighted average shares	26,114,000	26,043,000	26,323,000	26,138,000
Net income per common share, basic	$ 0.06	$ 0.09	$ 0.14	$ 0.20
Net income per common share, diluted	$ 0.06	$ 0.09	$ 0.14	$ 0.20
Antidilutive securities excluded from computation of earnings per share	1,516,657	3,254,285	2,194,757	2,019,690

Acquisition (Details) (USD $)	9 Months Ended				0 Months Ended
Acquisition (Details) (USD $)	Jun. 30, 2013	Sep. 30, 2012	Jun. 30, 2012	Sep. 30, 2011	Oct. 31, 2012 Etherios [Member]	Oct. 31, 2012 Maximum [Member]	Oct. 31, 2012 Common Stock [Member] Etherios [Member]
Business Acquisition [Line Items]
Total purchase price					$ 20,500,000
Cash, including cash in escrow					13,696,000
Cash acquired					800,000
Common stock					6,804,000
Number of shares							715,571
Common stock issued per common share					9.508
Amount in escrow					2,350,000
Escrow holdback					300,000
Escrow cash					2,050,000
Escrow cash period						18 months
Acquisition Related Costs	200,000
Goodwill	$ 102,611,000	$ 86,209,000	$ 85,544,000	$ 86,012,000	$ 17,120,000

Acquisition (Purchase Price Allocation) (Details) (USD $) In Thousands, unless otherwise specified					0 Months Ended		0 Months Ended
	Jun. 30, 2013	Sep. 30, 2012	Jun. 30, 2012	Sep. 30, 2011	Oct. 31, 2012 Etherios [Member]	Oct. 31, 2012 Existing Customer Relationships [Member] Etherios [Member]	Oct. 31, 2012 Existing Customer Relationships [Member] Etherios [Member] Minimum [Member]	Oct. 31, 2012 Existing Customer Relationships [Member] Etherios [Member] Maximum [Member]	Oct. 31, 2012 Non-compete Agreements [Member] Etherios [Member]	Oct. 31, 2012 Trade Name [Member] Etherios [Member]	Oct. 31, 2012 Order Backlog [Member] Etherios [Member]
Business Acquisition [Line Items]
Cash, including cash in escrow					$ 13,696
Common stock					6,804
Total					20,500
Fair value of net tangible assets acquired					1,367
Identifiable intangibles assets						1,400			1,100	440	360
Goodwill	102,611	86,209	85,544	86,012	17,120
Deferred tax liabilities related to identifiable intangibles					(1,287)
Total					$ 20,500
Weighted Average Useful Life					5 years 8 months 12 days
Useful life							6 years	8 years	5 years	7 years	1 year

Selected Balance Sheet Data (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2013	Sep. 30, 2012
Accounts receivable, net:
Accounts receivable	$ 25,343	$ 24,929
Less allowance for doubtful accounts	374	295
Accounts receivable, net	24,969	24,634
Inventories:
Raw materials	20,159	18,159
Work in process	411	428
Finished goods	4,726	5,848
Inventories	$ 25,296	$ 24,435

Marketable Securities (Details) (USD $)
In Thousands, unless otherwise specified

9 Months Ended

12 Months Ended

Jun. 30, 2013

Securities

Sep. 30, 2012

Schedule of Available-for-sale Securities [Line Items]

Number of securities below amortized cost basis

Number of securities

Amortized cost

$ 57,998

^[1]

$ 60,401

^[2]

Unrealized gains

Unrealized losses

(92)

^[3]

(28)

^[4]

Goodwill and other Identifiable Intangible Assets (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2013	Sep. 30, 2012
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	$ 82,902	$ 79,629
Accumulated amortization	(71,881)	(69,000)
Net	11,021	10,629
Purchased and Core Technology [Member]
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	46,248	46,597
Accumulated amortization	(44,193)	(43,639)
Net	2,055	2,958
License Agreements [Member]
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	2,840	2,840
Accumulated amortization	(2,737)	(2,682)
Net	103	158
Patents and Trademarks [Member]
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	11,924	10,943
Accumulated amortization	(9,302)	(8,469)
Net	2,622	2,474
Customer Maintenance Contracts [Member]
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	700	700
Accumulated amortization	(700)	(700)
Net	0	0
Customer Relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	18,699	17,504
Accumulated amortization	(13,531)	(12,465)
Net	5,168	5,039
Non-compete Agreements [Member]
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	2,131	1,045
Accumulated amortization	(1,178)	(1,045)
Net	953	0
Order Backlog [Member]
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	360	0
Accumulated amortization	(240)	0
Net	$ 120	$ 0

Income Taxes (Details) (USD $)	3 Months Ended					9 Months Ended
Income Taxes (Details) (USD $)	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Jun. 30, 2012	Dec. 31, 2011	Jun. 30, 2013	Jun. 30, 2012	Sep. 30, 2012
Income Tax Disclosure [Abstract]
Effective income tax rate						18.50%	20.60%
Discrete income tax (benefit)	$ (100,000)	$ (400,000)	$ (100,000)	$ 1,100,000	$ 100,000
Percentage points that reduced effective tax rate						(13.7)	(18.6)
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Unrecognized tax benefits, beginning balance			2,720,000			2,720,000
Increases related to prior year income tax positions						202,000
Decreases related to expiration of statute of limitations						(191,000)
Unrecognized tax benefits, ending balance	2,731,000					2,731,000
Unrecognized tax benefits that would impact effective tax rate	2,700,000					2,700,000
Significant Change in Unrecognized Tax Benefits is Reasonably Possible, Estimated Range of Change, Upper Bound	400,000					400,000
Income tax penalties and interest accrued	600,000					600,000		600,000
Accumulated undistributed foreign earnings	24,500,000					24,500,000
Minimum [Member]
Income Tax Contingency [Line Items]
Estimated unrecognized deferred tax liability	2,500,000					2,500,000
Maximum [Member]
Income Tax Contingency [Line Items]
Estimated unrecognized deferred tax liability	$ 3,500,000					$ 3,500,000

Contingencies (Details) (Patent Infringement [Member], USD $)	0 Months Ended
	Apr. 22, 2013	Oct. 23, 2012
Patent Infringement [Member]
Loss Contingencies [Line Items]
Litigation Settlement, Amount	$ 1,500,000	$ 500,000
Litigation settlement amount, net of taxes	$ 1,000,000
Litigation settlement amount, impact on diluted earnings per share	$ 0.04

Restructuring (U.S. Restructuring) (Details) (United States Restructuring [Member], USD $) In Millions, unless otherwise specified	5 Months Ended
	Sep. 30, 2012 employees	Apr. 26, 2012 Employee Termination Costs [Member]	Apr. 26, 2012 Other [Member]
Restructuring Cost and Reserve [Line Items]
Number of employees eliminated	30
Beginning Balance	$ 1.0	$ 0.6	$ 0.4
Ending Balance		$ 0.6	$ 0.4