Communication; Modbus Data Transfer - Viessmann Vitotronic SPS Service Instructions Manual

Communication

Modbus data transfer

Modbus connection via RS485:
M1 Pin1 X1 Pin10 X2
Pin1
X15
Pin8
X16
X17
X12 X18 X19 X13 X11
Fig. 29
Note
The RS485 interface is on X16.
Pin arrangement
RJ45
Pin1
Pin8
Pin1
Fig. 30
Not allocated
1
/RX/TX
2
RX/TX
3
GND
4
Termination
The internal terminator must be activated if the Saia
■
PLC is connected to the start or end of the RS485
bus
■ To do this, use the 2 wire jumpers from plug X16
■ Connect pins 5 and 6 to each other
■ Connect pins 7 and 8 to each other
X3 X4 X5
X10 X9 X8 X7 Pin8
Termination+
5
/RX/TX
6
RX/TX
7
Termination
8
Transmission cables
Signals RX/TX and /RX/TX are required for transmis-
■
sion
RX/TX and /RX/TX are connected 1 to 1 with the
■
opposite side. GND must be connected to the data
cable screen on at least one side
■ For equipotential bonding, GND can be connected
on both sides.
Configuring the system
X14
Pin1
X6
41