User Manual

4-4 Using Modbus RTU
20-COMM-H RS-485 HVAC Adapter User Manual
Publication 20COMM-UM009D-EN-P
Using the Modbus RTU Point
Map for I/O
On Modbus, data transfers are used to transfer the I/O data that controls the
drive and sets its Reference. Note that output I/O is data that the master
device sends and the adapter receives. Input I/O is status data that the
adapter sends and the master device receives.
Important:In order for the drive to use the I/O and Reference from the
Modbus RTU network, you must set parameters in it and the
adapter to receive the I/O and Reference. For details, refer to
Setting the I/O Configuration
on page 3-5.
Write Various Holding Registers
4x0001 Product Logic Command
4x0002 Reference Lo (Bits 0…15 of 32-bit Reference)
4x0003 Reference Hi (Bits 16…31 of 32-bit Reference or whole 16-bit Reference)
4x0004 Parameter # for USER IN1
4x0005 Parameter # for USER IN2
4x0006 Parameter # for USER IN3
4x0007 Parameter # for USER IN4
4x0008 Parameter # for USER IN5
4x0009 Parameter # for USER IN6
4x0010 Parameter # for USER IN7
4x0011 Parameter # for USER IN8
4x0012 Write USER OUT1
4x0013 Write USER OUT2
4x0014 Write USER OUT3
4x0015 Parameter # for USER OUT1
4x0016 Parameter # for USER OUT2
4x0017 Parameter # for USER OUT3
4x0018 Write Datalink A1 In
4x0019
4x0020 Write Datalink A2 In
4x0021
4x0022 Write Datalink B1 In
4x0023
4x0024 Write Datalink B2 In
4x0025
4x0026 Write Datalink C1 In
4x0027
4x0028 Write Datalink C2 In
4x0029
4x0030 Write Datalink D1 In
4x0031
4x0032 Write Datalink D2 In
4x0033
Direct Parameter Access
4x0100 + param # 20-COMM-H Parameter Direct Access (with adapter in 16-bit mode)
4x0100 + (param # x 2) 20-COMM-H Parameter Direct Access (with adapter in 32-bit mode)
4x1000 + param # Drive Parameter Direct Access (with adapter in 16-bit mode)
4x1000 + (param # x 2) Drive Parameter Direct Access (with adapter in 32-bit mode)
Table 4.C Adapter Modbus Register Map (Continued)
Modbus Register Function