Condensed Consolidated Statements of Cash Flows (unaudited) - USD ($) $ in Thousands	9 Months Ended
	Jun. 30, 2018	Jun. 30, 2017
Cash flows from operating activities:
Net (loss) income	$ (11,567)	$ 6,030
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization expense	4,102	2,646
Stock-based compensation expense	2,713	2,672
Provision adjustments related to doubtful accounts	599	7
Provision adjustments related to product warranty	336	488
Impairments of equipment	0	468
Net loss (gain) on disposal of equipment	39	(322)
Other	100	321
Total non-cash adjustments	7,889	6,280
Changes in operating assets and liabilities:
Accounts receivable	6,796	(3,878)
Inventory	1,777	(1,782)
Other assets	(3,192)	(2,627)
Accounts payable	(1,662)	2,951
Accrued expenses and other current liabilities	1,199	834
Total change in operating assets and liabilities	4,918	(4,502)
Net cash provided by operating activities	1,240	7,808
Cash flows from investing activities:
Purchase of equipment	(3,756)	(7,262)
Proceeds from disposal of property, plant and equipment	77	339
Net cash used in investing activities	(3,679)	(6,923)
Cash flows from financing activities:
Proceeds from stock plans	445	797
Tax withholding paid on behalf of employees for stock-based awards	(1,257)	0
Net cash (used in) provided by financing activities	(812)	797
Effect of exchange rate changes on foreign currency	2	(35)
Net (decrease) increase in cash, cash equivalents and restricted cash	(3,249)	1,647
Cash, cash equivalents and restricted cash at beginning of period	68,754	64,870
Cash, cash equivalents and restricted cash at end of period	65,505	66,517
SUPPLEMENTAL DISCLOSURE OF CASH FLOW INFORMATION
Cash paid during the period for interest	47	55
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	1,291	(549)
Issuance of common stock to Board of Directors	$ 0	$ 410