Hello, can I implement Modbus tcp in a bus topology?
I have 6 modbus tcp devices connected in bus topology and I cannot read the modbus registers.

 

Yes and no. This is only possible with dual port Ethernet devices that incorporate an embedded Ethernet switch.

You cannot use a bus topology with single port Ethernet devices (using a T adapter, for example).

To confirm you have an Ethernet connection to your Modbus devices, you can try pinging the devices using a laptop on the same network (or as the first or last device when using dual port Ethernet devices).

 

Only VIA ethernet switch. The ethernet stitch could be used as common(bus)-link.
You might be able to do this connection with Modbus RTU

 

Hello, can I implement Modbus tcp in a bus topology?
I have 6 modbus tcp devices connected in bus topology and I cannot read the modbus registers.

Hello,
Modbus TCP/IP can be implemented in star topology, simply use a comm switch and connect all your devices. you can use also ring topology, be sure your coomm switches have DLR ability.