AirLink 7543 Gas Monitor Operator’s Manual
Chapter 3: Installation • 17
RS-485 Modbus Wiring (Modbus Out)
NOTE:
The Modbus output is not available if Wireless HART is being used.
1. Open the enclosure box to expose the Front Panel.
2. Unscrew the two thumb-screws on the Front Panel.
3. Open the Front Panel so that the Terminal Board is exposed.
4. Locate the Modbus Out Terminal Block.
5. Connect the yellow wire from a DB-9 connector (or the connector-type that best suits your
application) to the terminal labeled “A” on the Modbus Out Terminal Block.
6. Connect the white wire from a DB-9 connector to the terminal labeled “GND” on the Modbus Out
Terminal Block.
7. Connect the brown wire from a DB-9 connector to the terminal labeled “B” on the Modbus Out
Terminal Block.
8. Plug the DB-9 connector into a PLC.
Figure 7: Modbus Out Wiring
9. Close the Front Panel.
10. Screw in the thumb-screws.
11. Close the enclosure box.
12. Clamp down the enclosure latches.
