Modbus Installation | 52
Appendix A
Modbus – Field Retrofit for NHRS Models
Step A – Unpacking
The Field kit is used to provide a simple hardware interface between the humidifier and Modbus
BMS RS485 connection. Because the NHRS Humidifier speaks a different language, a
Translation card is provided with the hardware kit. First start by reviewing the contents of
Modbus Field retrofit kit, you should have the following items:
1 Ribbon cable 10 pin to 20 pin
1 Translation Printed Circuit board (colour blue)
1 terminal strip (3 pole) with RJ 11 termination cable
4 Nylon Standoffs (white)
4 Nylon screws (white)
Step B – Hardware installation
1 Locate the main PCB board inside the humidifier.
2 Connect one end of the ribbon cable (10 pin end) to the Humidifier’s COM port.
Figure 7: Humidifier COM port
3 Route the ribbon cable through the punch out on the humidifiers front electrical panel