Supplementary Balance Sheet Information (Tables)

12 Months Ended

Sep. 30, 2023

Organization, Consolidation and Presentation of Financial Statements [Abstract]

Summary of accounts receivable

The following is a summary of accounts receivable at September 30, 2023 and 2022 (in thousands):

	September 30,
	2023		2022
Accounts receivable	$	164,592	$	168,920
Less allowance for expected credit losses		(8,057)		(5,162)
Accounts receivable, net	$	156,535	$	163,758

Summary of allowance for expected credit losses

The allowance for expected credit losses for the fiscal years ended September 30, 2023, 2022 and 2021 is as follows (in thousands):

	Year Ended September 30,
	2023		2022		2021
Balance at beginning of period	$	5,162	$	4,318	$	7,146
Provisions		8,849		3,536		3,445
Payments received		(5,884)		(2,278)		(5,481)
Write-offs and adjustments		(70)		(414)		(792)
Balance at end of period	$	8,057	$	5,162	$	4,318

Summary of inventories

The following is a summary of inventories at September 30, 2023 and 2022 (in thousands):

	September 30,
	2023		2022
Raw materials and purchased parts	$	59,861	$	39,685
Work-in-process		11,400		4,816
Finished goods		56,937		41,043
Total inventories	$	128,198	$	85,544

The activity for excess and obsolete inventory reserves is as follows for the fiscal years ended September 30, 2023, 2022 and 2021 (in thousands):

	Year Ended September 30,
	2023		2022		2021
Balance at beginning of period	$	4,082	$	3,681	$	3,136
Provisions		3,324		1,752		1,522
Inventory disposals and adjustments		(2,415)		(1,351)		(977)
Balance at end of period	$	4,991	$	4,082	$	3,681

Summary of valuation allowance for deferred tax assets

The activity for valuation allowance for deferred tax assets is as follows for the fiscal years ended September 30, 2023, 2022 and 2021 (in thousands):

	Year Ended September 30,
	2023		2022		2021
Balance at beginning of period	$	5,927	$	8,592	$	10,623
Charge to income tax provision (benefit)		1,137		1,337		(3,247)
Charged to other accounts		1,284		(4,002)		1,216
Balance at end of period	$	8,348	$	5,927	$	8,592

Summary of product warranty and retrofit activity

The following is a summary of product warranty and retrofit activity on a gross basis for the fiscal years ended September 30, 2023, 2022 and 2021 (in thousands):

	Year Ended September 30,
	2023		2022		2021
Balance at beginning of period	$	2,890	$	2,330	$	2,211
Adjustments for acquisitions and divestitures		2,475		254		—
Accruals for warranties during the year		8,198		2,438		2,300
Costs incurred during the year		(3,340)		(2,132)		(2,181)
Balance at end of period	$	10,223	$	2,890	$	2,330