Note 1 - Significant Accounting Policies (Details Textual) - USD ($)	6 Months Ended	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Jun. 30, 2015
Product Return Period		30 days
Deferred Revenue	$ 1,098,000	$ 892,000	$ 1,098,000
Restricted Cash and Cash Equivalents, Current	100,000	$ 100,000	100,000
Power Supplies and Repair Warranty, Term		3 years
Advertising Expense	58,000	$ 73,000	$ 69,000	$ 150,000
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period		4 years
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount		23,333	40,000	43,000
Deferred Profit	0	$ 0	$ 0
Impairment of Long-Lived Assets Held-for-use	$ 0	$ 0	$ 0	$ 0
XLS and RLS Models [Member]
Advance Replacement Warranty Period		3 years
XLS Libraries [member]
Warranty, Onsite Service Period		1 year
Geographic Concentration Risk [Member] | Sales Revenue, Net [Member] | Outside North America [Member]
Concentration Risk, Percentage	41.90%	46.10%	50.30%	54.00%
Customer Concentration Risk [Member] | Sales Revenue, Net [Member] | Largest Customer [Member]
Concentration Risk, Percentage	10.70%	10.60%	14.80%	11.10%
Customer Concentration Risk [Member] | Accounts Receivable [Member] | Largest Customer [Member]
Concentration Risk, Percentage		22.30%	8.20%