Segment Information and Major Customers (Details) $ in Thousands	3 Months Ended								12 Months Ended
	Sep. 30, 2015 USD ($) customer	Jun. 30, 2015 USD ($)	Mar. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)	Sep. 30, 2014 USD ($) customer	Jun. 30, 2014 USD ($)	Mar. 31, 2014 USD ($)	Dec. 31, 2013 USD ($)	Sep. 30, 2015 USD ($) customer segment	Sep. 30, 2014 USD ($) customer	Sep. 30, 2013 USD ($) customer
Segment Reporting Information [Line Items]
Sales Revenue, Goods, Net									$ 195,497	$ 172,846	$ 173,078
Sales Revenue, Services, Net									$ 17,361	19,855	22,303
Number of operating segments | segment									1
Number of reportable segments | segment									1
Total revenue	$ 56,446	$ 54,538	$ 53,151	$ 48,723	$ 51,612	$ 47,885	$ 45,882	$ 47,322	$ 212,858	192,701	195,381
Total property, equipment and improvements	$ 14,357				$ 13,231				$ 14,357	$ 13,231	$ 13,910
Number of customer representing over ten percent of revenue | customer									0	0	0
Number of customer representing over ten percent of consolidated accounts receivable | customer	2				0				2	0
North America, primarily United States
Segment Reporting Information [Line Items]
Total revenue									$ 136,603	$ 116,421	$ 116,541
United States
Segment Reporting Information [Line Items]
Total property, equipment and improvements	$ 14,103				$ 12,813				$ 14,103	$ 12,813	$ 13,321
United States | U.S. Export Net Sales
Segment Reporting Information [Line Items]
Percentage of concentration									37.70%	41.20%	41.70%
United States | Accounts Receivable | Customer 1
Segment Reporting Information [Line Items]
Percentage of concentration									10.20%
United States | Accounts Receivable | Customer 2
Segment Reporting Information [Line Items]
Percentage of concentration									11.00%
Europe, Middle East and Africa
Segment Reporting Information [Line Items]
Total revenue									$ 47,523	$ 47,729	$ 48,815
Asia
Segment Reporting Information [Line Items]
Total revenue									22,907	22,762	24,507
Latin America
Segment Reporting Information [Line Items]
Total revenue									5,825	5,789	5,518
International, primarily Europe
Segment Reporting Information [Line Items]
Total property, equipment and improvements	$ 254				$ 418				254	418	589
Cellular routers and gateways
Segment Reporting Information [Line Items]
Sales Revenue, Goods, Net									58,666	39,215	33,227
RF
Segment Reporting Information [Line Items]
Sales Revenue, Goods, Net									34,373	29,094	29,157
Embedded
Segment Reporting Information [Line Items]
Sales Revenue, Goods, Net									51,063	49,681	57,597
Network
Segment Reporting Information [Line Items]
Sales Revenue, Goods, Net									51,395	54,856	53,097
Growth hardware product and all services
Segment Reporting Information [Line Items]
Total revenue									133,572	109,763	110,350
Mature hardware products
Segment Reporting Information [Line Items]
Total revenue									$ 79,286	$ 82,938	$ 85,031