Alarm Recovery
E2 MODBUS Network Wiring • 21
18 E2 MODBUS Network Wiring
• Connect MODBUS Network to the RS485 Connector on the E2 PIB board (Belden 8641 recommended).
• Note to wire the RS485 +/- polarity at the E2 in the
reverse
of the XEV22D devices.
• Position the three termination jumpers to the UP (terminated) position to provide RS485 termination at the E2.
• Do not connect the shield of the MODBUS network to the E2 PIB center terminal. Instead, use a 100 ohm 1/2 watt
resistor to connect the MODBUS cable shield to earth ground.
• At each XEV22D device, wire the MODBUS cable to the RS485 +/- terminals and connect the MODBUS shield to
the pin
16
terminal.
• Terminate the end of the MODBUS network at the last XEV22D device on the daisy chain with the MODBUS ter-
mination block (
P/N 535-2711
), or by connecting a 150 ohm resistor between the /- terminals.
Figure 18-1 - XEV22D to E2 Wiring Diagram (E2 PIB version 3.xx and below shown in this example)
CAUTION! For the XR, XM, and XEV series of controllers, the shield wire must not come into contact with
any other wire or ground source. If contact with other wires or devices does occur, the 485 MODBUS net-
work will malfunction or connected devices will be damaged. This applies to all installations where the
shield is tied to ground through a 100 ohm ½ Watt resistor.
