... can work 6 to 8 hours; 8,ER-691D ER-690D supports ID card, support for password operation ... the user card in the corresponding consumptio; ER-691D ER-690D didn't this function12,ER-691C ER ... -690C disoperation refund function; ER-691D didn't this functionPerformance parameters:1,Power supply voltage ... ; card and Mifare Light card4,Operating frequency: ER-691D ER-690D 125KHz; ER-691C ER-690C: 13 ...
