Adding MODBUS TCP slaves
Regular MODBUS TCP addressing
When a single MODBUS TCP device has its own IP address on the network,
then the IP address is self sufficient to identify that slave.
New MODBUS TCP slaves can be created by using one of the
following patterns:
- 127.0.0.1
- Create just one slave that will reply to requests received
from any network interface.
- 192.168.10.100
- Create just one slave that will only reply to requests received
on the network interface whose IP address is 192.168.10.100.
- 10.23.6.2, 10.23.6.8
- Create 2 slaves that will reply to requests received
on network interfaces whose IP addresses are 10.23.6.2,
and 10.23.6.8.
- 10.23.6.2-10.23.6.8
- Create 9 slaves that will reply to requests received
on network interfaces whose IP addresses are 10.23.6.2,
10.23.6.3, ..., 10.23.6.7 and 10.23.6.8.
Note: the comma can be replaced by a new line. White
spaces following the comma are ignored.
Multiple slaves sharing the same IP address
When more than one MODBUS TCP device share the same IP address on the network,
then the IP address alone is not sufficient to identify each slave. This is
the case when, for example, the IP address is owned by a TCP/SERIAL gateway
and the actual MODBUS slaves are using MODBUS RTU protocol.
Such MODBUS slaves must be identified by both an IP address and a slave
number, and can be created by using one of the
following patterns:
- 127.0.0.1(17)
- Create juste one slave at IP address 127.0.0.1 (listen on all
network interfaces) and slave number 17.
- 192.168.10.100(10-15)
- Create 6 slaves sharing the same IP address (local network interface
192.168.10.100). Each slave is assigned a slave number ranging from 10
to 15 included.