What is the max distance without and with repeater in a modbus network?
Is it possible to hot replace a node without cause some troubles to the comunications?
Thanks,
Malheiros

 

The maximum distance allowed on a Modbus Network is going to depend on the topology. In order for Modbus to be used in a multi-drop configuration you should be using RS485. In order to determine what the maximumn allowed distance will be you need to consult the RS232/RS485 Conveter manufactures specifications.

Depending on how the RS232 connection is made to the the converter you should be able to replace the node (PLC) and only cause a disruption to that particular node. If you need to replace the converter, then it will depend on how the cabling has been installed.

Regards
Robert Willis

 

I think that you are referring to a Modbus Plus network.

For Modbus, this depends upon the media. RS232 or RS485? Cable or fibre or radio or microwave?

For Modbus Plus, again you can go cable or fibre.

For Modbus Plus, approved cable, distance is 1500 ft before a repeater.

Yes, you can add/remove nodes on a properly installed and terminated Modbus Plus network without adversely affecting the other nodes on the network.

To avoid delays in getting a valid response, you should ask as specific and detailed question as possible.