... terminal 2)support polar-reverse,12 or 16 KHz pulse signal 3)support GPRS 4 line Wireless Terminal Unique Functions1,GSM ... Support secondary dial.5,Lock card, lock terminal.6,Send polarity reversal signal for billing meter while connection.7,Sending 12/16KHz pulse ... hour when out of mains supply. (Optional)10,Transmit tariff for our company phone billing meter. (Optional)Technical Specifications1,Work ...