DC Power Wiring
Connect 10 - 30 VDC from the PLC (or other source) to the VT-MODEM-2 as shown. The modem can be powered from any industrial DC power supply such as the SIXNET ST-PS-024-02N, VT-PS-024-01N or equivalent. All the screw terminals should be tightened to a maximum of 3.48 in-lbs.
Telephone Lines
Connect phone lines to the RJ11 jacks as appropriate. One RJ-11 jack is provided to connect directly to a telephone (optional) and the second RJ-11 jack functions as the connection to the telephone network.
PLC Self-Dial I/O Connections
Connect a 10-30VDC signal to the ‘From PLC’ (trigger input) terminal. An OFF to ON transition of this signal starts the auto-dialing sequence. The modem will call and remain connected while the signal is ON. When the signal goes false, the modem will terminate the connection or the call in progress. The ‘To PLC’ (on-line output) terminal will go ON (ON = user supplied VDC input) when a modem to modem connection has been established and the proper ‘Acknowledge Message’ has been received.