Hello,
Is it possible to run Modbus TCP protocol if cable lenght is 130-140m? It will work if I use cat6 instead of cat5? do you have experience with that?

 

The spec for Ethernet is a performance spec, in other words, for a given Ethernet speed, a 100m cable will support so many bits per second.

That does not mean that the signal dies if the cable is 102m in length instead of 100.0 meters in length. The longer length means that the spec/standard's speed performance is not guaranteed.

Years ago (before widespread WiFi) in the 10Mb era, a friend ran 500m of Cat 5 cable from his house to the town park, through the neighbor's woods, for a local weekend festival so the festival organizers could have access to an internet connection for some reason. Given the low traffic, it worked fine. Unshielded cable worked fine for the low-noise woods environment.

Go for it.

 

If this is something you want to work reliably then stick to the industry standard of 100m of copper Ethernet cable between switches. You can achieve 140m by adding switches or use fibre optic cable if you don’t want a switch in the middle.

 

Hello,
Is it possible to run Modbus TCP protocol if cable lenght is 130-140m? It will work if I use cat6 instead of cat5? do you have experience with that?

Do expect signal attenuation when the distance beyond 80 meter (again vendor specific)
Would prefer to have fiber converter if it exceeds more than 50 Meters.
Else you have compromise on the baurd rate. Slower will work relatively better for longer distance.

Wonder why still modbus which is unsecured ? Why not Profinet or EtherCAT or something better?

 

Do expect signal attenuation when the distance beyond 80 meter (again vendor specific)
Would prefer to have fiber converter if it exceeds more than 50 Meters.

There is always signal attenuation, the longer the cable the worse it gets. However all the vendors I have seen state 100m limit as attenuation is negligible up to this distance

 

Do expect signal attenuation when the distance beyond 80 meter (again vendor specific)
Would prefer to have fiber converter if it exceeds more than 50 Meters.
Else you have compromise on the baurd rate. Slower will work relatively better for longer distance.

Wonder why still modbus which is unsecured ? Why not Profinet or EtherCAT or something better?

Correction. Baud rate is only for Modbus serial not for Modbus TCP/IP.