Honeywell HVAC232 Series, Applications Manual

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Application manual HVAC232/402 | Document 27-652 | Issue ENG06 | 2019-08-07 134
10.18 Termination resistor
The RS-485 bus is terminated with termination resistors of 120 ohms
in both ends. HVAC232/402 has a built-in termination resistor which is
switched off as a default (presented below). The termination resistor can be
switched on and off with the right hand dip switch located above IO-termi-
nals in the front of the drive (see below).
4 5 13 14 15 16 20 18
1 2 3 6 7 8 9 10
22 23 2 6
24 25
AI2 GND DO- DI4 DI5 DI6 AO DO+ R13 R14 * R24
+10VAI1 GND 24V DI-C DI1 DI2 DI3 A B R21 R22
DI Enc
o N
or
AO
V m
A
AI
2
V m
A
RS
485
- te
rm
ON
OFF
J500
*ENCO = logic input configured as encoder input
Fig. 68. HVAC232/402 I/O
10.19 Modbus address area
The Modbus interface of HVAC232/402 uses the ID numbers of the ap-
plication parameters as addresses. The ID numbers can be found in the
parameter tables in „9
Standard application parameters“ on page
55. When several parameters / monitoring values are read at a time, they
must be consecutive. 11 addresses can be read and the addresses can be
parameters or monitoring values.
NOTE:
With some PLC manufacturers, the interface driver for Modbus
RTU communication may contain an offset of 1 (the ID number
to be used would then subtract 1).
10.20 Modbus process data
Process data is an address area for fieldbus control. Fieldbus control is
active when the value of parameter 2.1 (Control place) is 1 (= fieldbus). The
content of the p()rocess data can be programmed in the application. The
following tables present the process data contents in HVAC232/402 Appli-
cation.