Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2017
Cash flows from operating activities:
Net loss	$ (35,984)	$ (17,453)	$ 8,235
Adjustments to reconcile net loss to net cash provided by operating activities:
Depreciation and amortization expense	7,142	5,617	3,757
Stock-based compensation expense	2,607	3,648	3,602
Provision adjustments related to doubtful accounts	62	599	23
Provision adjustments related to product warranty	186	431	573
Impairments of equipment	0	0	506
Net (gain) loss on disposal of equipment	(302)	34	(456)
Other	464	412	(50)
Total non-cash adjustments	10,159	10,741	7,955
Changes in operating assets and liabilities, net of acquired assets and assumed liabilities:
Accounts receivable and contract assets	3,980	2,372	(3,859)
Inventory	6,486	5,067	(140)
Prepaid expenses and other assets	(238)	784	(2,397)
Accounts payable	(4,539)	477	2,095
Accrued expenses and other current liabilities	4,985	(518)	(188)
Total change in operating assets and liabilities	10,674	8,182	(4,489)
Net cash (used in) provided by operating activities	(15,151)	1,470	11,701
Cash flows from investing activities:
Purchases of equipment	(10,790)	(6,583)	(9,600)
Acquisition of business, net of cash acquired	(21,483)	0	0
Proceeds from disposal of property, plant and equipment	470	82	474
Net cash used in investing activities	(31,803)	(6,501)	(9,126)
Cash flows from financing activities:
Proceeds from borrowings of credit facilities	5,497	0	0
Proceeds from exercise of equity awards	505	770	1,306
Taxes paid related to net share settlement of equity awards	(203)	(1,257)	0
Net cash provided by (used in) financing activities	5,799	(487)	1,306
Effect of exchange rate changes provided by foreign currency	(63)	(41)	3
Net (decrease) increase in cash, cash equivalents and restricted cash	(41,218)	(5,559)	3,884
Cash, cash equivalents and restricted cash at beginning of period	63,195	68,754	64,870
Cash, cash equivalents and restricted cash at end of period	21,977	63,195	68,754
SUPPLEMENTAL DISCLOSURE OF CASH FLOW INFORMATION
Cash paid during the period for interest	126	63	71
Cash paid during the period for income taxes	68	131	114
NON-CASH INVESTING AND FINANCING ACTIVITIES
Changes in accounts payable related to purchases of equipment	(180)	755	(861)
Issuance of common stock to Board of Directors	$ 0	$ 0	$ 331