If there are 900 m between the two PLCs, then an Ethernet based solution cannot go directly via copper cables.
You would have to go via fiber or connect via a plantwide network. To mix your system with a plant-wide network can be a disadvantage or an advantage. You would have to coordinate with the local IT department. Consider what happens when there is maintenance on the plant-wide network. Can your system accept if the connection is lost ?
At 187.5 kbps Profibus can reach 1200 m.
As I see it, Profibus is easy and inexpensive.
Profibus cable costs 10 DKK/m, fiber much more.
You would have to go via fiber or connect via a plantwide network. To mix your system with a plant-wide network can be a disadvantage or an advantage. You would have to coordinate with the local IT department. Consider what happens when there is maintenance on the plant-wide network. Can your system accept if the connection is lost ?
At 187.5 kbps Profibus can reach 1200 m.
As I see it, Profibus is easy and inexpensive.
Profibus cable costs 10 DKK/m, fiber much more.