Biddle HR 25 - Connecting the Unit to Modbus

HR MANUAL INSTALLATION
Manual version 4.1 (26-07-2018)
en-21
en
2.7 Connecting the unit to Modbus
2.7.1 Communication parameters
Standard values of the communication parameters for Mod-
Bus are:
The turnaround time between the unit and Modbus is 4.2
msec.
The default value for the Modbus node address is 1.
Note:
n You can modify the parameters via b-touch
menu > Maintenance > Modbus settings or
via Modbus register addresses 460-464.
2.7.2 Wiring
A twisted-pair cable must be used for connection to the Mod-
bus system. The cable must also have a third core for the
GND (grounding). Normally, a four-pole, twisted-pair cable is
used; one pair is used for communication and one core from
the other pair is used as the GND.
Modbus A = -
Modbus B = +
GND = ground
Note:
n If there is no communication, this may be caused by
incorrectly connected wiring. Swap the A- and B+
wires.
COMMUNICATION PARAMETER VALUE
Baud rate 9600
DATA 8
Parity none
Stop bits 1