There may be different components of the control system connected to the network:
- process stations
- management stations
- wireless access points
- routers to connect to other networks
- terminal servers for remote connection of I/O buses
The devices must be addressed properly to be able to communicate to each other.
IP version 4 addressing is used, which provides addresses as 4 numbers ranged 0…255, separated by dots. For private networks, which is the case of technological networks, the following ranges are reserved:
- 10.0.0.0 – 10.255.255.255
- 172.16.0.0 – 172. 16. 255.255
- 192.168.0.0 – 192.168.255.255
The exception may be embedding of the process stations into a customer network with its own numbering rules, e.g. as part of an international infrastructure. Consult the IT administrator for details.
If the control system designer is responsible for the network numbering plan, addresses of 192.168.1.10 and higher are usually uused, with network mask of 255.255.255.0. It is also possible to state in the project that the network numbering is up to the software engineer who commissions the site and who should consult the numbering plan with the customer or end user.