Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Cash flows from operating activities:
Net (loss) income	$ (3,153)	$ 3,605
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization expense	2,605	1,685
Stock-based compensation expense	1,848	1,581
Provision adjustments related to doubtful accounts	75	7
Provision adjustments related to product warranty	282	303
Impairments of equipment	0	468
Net loss on disposal of equipment	39	0
Other	(643)	574
Total non-cash adjustments	4,206	4,618
Changes in operating assets and liabilities:
Accounts receivable	4,422	975
Inventory	2,041	(2,357)
Other assets	(2,812)	(1,582)
Accounts payable	(4,923)	1,489
Accrued expenses and other current liabilities	304	1,035
Total change in operating assets and liabilities	(968)	(440)
Net cash provided by operating activities	85	7,783
Cash flows from investing activities:
Purchase of equipment	(2,735)	(4,567)
Proceeds from disposal of property, plant and equipment	77	0
Net cash used in investing activities	(2,658)	(4,567)
Cash flows from financing activities:
Proceeds from stock plans	442	779
Tax withholding paid on behalf of employees for stock-based awards	(1,139)	0
Net cash (used in) provided by financing activities	(697)	779
Effect of exchange rate changes on foreign currency	45	(67)
Net (decrease) increase in cash, cash equivalents and restricted cash	(3,225)	3,928
Cash, cash equivalents and restricted cash at beginning of period	68,754
Cash, cash equivalents and restricted cash at end of period	65,529	68,798
SUPPLEMENTAL DISCLOSURE OF CASH FLOW INFORMATION
Cash paid during the period for interest	31	38
Cash paid during the period for income taxes	130	79
NON-CASH INVESTING AND FINANCING ACTIVITIES
Changes in accounts payable related to purchases of equipment	(235)	(255)
Issuance of common stock to Board of Directors	$ 0	$ 410