20
WIKA operating instructions model A2G-200
20210728.01 10/2021 EN/DE
EN
PARITY BIT
■
Press
PARITY BIT
in the
MODBUS
menu in order to set to odd or even or to switch
off a discrete character check bit for error detection in the parity check.
■
Press the desired setting for the parity bit.
■
Press
in order to confirm the setting.
�� The parity bit is set.
5.5 Modbus
®
protocol
Functions for the Modbus
®
communication
Function code
Description
01
Read coil status
02
Read input status
03
Read holding registers
04
Read input registers
05
Force single coil
06
Preset single register
07
Read exception status
15
Force multiple coils
16
Preset multiple registers
17
Report slave ID
Function code 02 - Read input status
Register Parameter description
Data type Value
Range
1x0001
Relay status
Bit 0
0…1
On/Off
1x0002
Relay trend
0…1
0 = increasing
1 = decreasing
Function code 03 - Read holding registers
Register Parameter description
Data type Value
Range
4x0001
Parameter for analogue
output
16 bit
0…3
0 = CO2, 1 = r.F.,
2 = T, 3 = MAX
4x0002
CO₂ high limit
500…2000
500 … 2,000 ppm
4x0003
CO₂ low limit
0…1900
0 … 1,900 ppm
4x0004
R. h. high limit
100…1000
10.0 … 100.0 %
4x0005
R. h. low limit
0…900
0.0 … 90.0 %
4x0006
T high limit
50…500
5.0 … 50.0 °C
5. Commissioning, operation
