INCOME TAXES - Deferred tax assets and liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Sep. 30, 2019
Deferred tax assets:
Inventory	$ 85	$ 102
Accrued compensation and vacation	137	162
Accrued expenses and other	172	379
Domestic net operating loss carryforwards	3,580	3,282
Basic difference for intangible assets	457	254
Stock compensation expense	96	2
AMT credit carryover	0	31
Leases	108	0
PPP loan expenses	1,276	0
Total deferred tax assets	5,911	4,212
Deferred tax liabilities:
Prepaid expenses	(143)	(121)
Basis difference for fixed assets	(211)	(219)
Goodwill	(141)	0
Total deferred tax liabilities	(495)	(340)
Total net deferred tax assets	5,416	3,872
Valuation allowance for net deferred tax assets	(5,557)	(3,841)
Net deferred tax asset (liability)	$ (141)
Net deferred tax asset (liability)		$ 31