Selected Balance Sheet Data (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Sep. 30, 2016
Accounts receivable, net:
Accounts receivable	$ 31,365	$ 30,885
Less allowance for doubtful accounts	341	209
Less reserve for future returns and pricing adjustments	2,169	1,991
Total accounts receivable, net	28,855	28,685
Inventories:
Raw materials	24,050	21,116
Work in process	484	802
Finished goods	5,704	4,358
Total Inventories	30,238	26,276
Property, Plant and Equipment, Net
Total property, equipment and improvements, gross	39,944	37,519
Less accumulated depreciation and amortization	27,143	23,478
Total property, equipment and improvements, net	12,801	14,041
Land
Property, Plant and Equipment, Net
Total property, equipment and improvements, gross	1,800	1,800
Buildings
Property, Plant and Equipment, Net
Total property, equipment and improvements, gross	10,522	10,522
Improvements
Property, Plant and Equipment, Net
Total property, equipment and improvements, gross	3,445	3,239
Equipment
Property, Plant and Equipment, Net
Total property, equipment and improvements, gross	17,133	15,778
Purchased Software
Property, Plant and Equipment, Net
Total property, equipment and improvements, gross	3,571	3,377
Furniture and Fixtures
Property, Plant and Equipment, Net
Total property, equipment and improvements, gross	$ 3,473	$ 2,803