CNV520 working mode description

[user181]

Good morning,
I would like some information on the new Modbus TCP/IP - Modbus RTU CNV520-21AD converter.

Does this CNV520 converter work on the same principle as the CNV510, i.e. with exchange tables to configure?

[Pixsys tecnico 1]

Hi,
the CNV520 is a simple "bridge", which works without an exchange table.

It does not work like the other CNV510s but simply "converts" the Modbus TCP/IP request into an RTU one, on the RS485 serial.

The master PLC must specify, in the Modbus TCP/IP query, the destination slave, which is the number of the slave on the Modbus RTU side to be queried.

This is a simplified way of working, which is only good with the Modbus TCP/IP protocol towards the RTU one, because the protocols are very similar to each other (in the Modbus TCP/IP frame there is obviously also the information of the IP address of destination).

In the CNV520 you need to configure (through the integrated WebServer, the Modbus TCP/IP registers or the DeviceFinder Windows PC application):
- its IP address (for the Modbus TCP/IP part)
- the speed and format of the RS485 serial port (for the Modbus RTU part)

[cupidforearm]

Thank you for the informationcoreball you have provided. It is very useful.