The WBS-670 / 680 series base stations cannot remotely power RS-500 or RS-600 series beltpacks connected directly to the base station.  There is no DC power available at pin 2 to do this nor is there a 200 ohm termination at the base station 2-wire PL connectors.   The WBS 2-wire PL interface on the base station requires a Clear-Com power supply or main station to properly power and terminate the PL interface on the wireless base station as the 2-wire PL interface needs approximately 30Vdc to operate. For stand alone use or stand alone use of linked base stations a termination for the wireless base (in essence a 220 ohm resistor connected to pins 1 and 3 of a 3-pin female or male XLR) can be constructed.  Attached below is a simple PDF of the termination using a 3-pin XLR connector.  The other alternative would be to simply switch the interface setting from 2-wire to 4-wire to prevent any audio oscillations from an un-terminated 2-wire PL port on the base station.