m340 and hmi with modbus-TCP

I want to communicate m340 342020 cpu with weintek hmi. Hmi Ip is 192.168.1.20 (port 8000) and m34 IP is 192.168.1.50 .
Register addresses (modbus) are between 46000-46100. I wrote addm, readvar function , but ı couldn't success.

I think you need to use port 502. The blocks dont give that type of flexibility. Why not make the hmi the client?

robertkjonesjr said:

I think you need to use port 502. The blocks dont give that type of flexibility. Why not make the hmi the client?

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Of course m340 server, and hmi is as client.
we will just read data from hmi (46000-x)

If the hmi is doing the reading and writing then you dont need any code in the plc. You just need to setup the ethernet port in the cpu (or noe)and make sure you locate the variables. To locate the variables go to the variable table and set the address.

Sorry I misread -

we will just read data from hmi

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Why are you trying to read from the hmi - does the hmi even have a modbus master driver (not many do)
Normally the hmi reads from the plc

Sorry I have to explain detail
A s7-200 and weintek hmi are already exist. I have projected new system with m340 and citect ( netwotk with 8 remote ). Costumer wants to join old system (s7-200 and hmi) to my system (m340-citect).
They permission connect to with network only hmi and don't want to change any program. I must read from hmi (modbus tcp) 46000-x address.

Then as I said the hmi must have a Modbus Master driver. This is not the standard modbus driver.

kamil_ozkan said:

Of course m340 server, and hmi is as client.
we will just read data from hmi (46000-x)

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Some thong is not right here modbus tcp is client/server protocol.
Modbus TCP Server serves data like slave in Modbus RTU
Shouldn't PLC be client and HMI server?

kamil_ozkan said:

Hmi Ip is 192.168.1.20 (port 8000)

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Reading data from an HMI is unusual, but not unheard of. Redlion has a Modbus slave driver that I have used. I also understand the need to approach the upgrade where you 'don't change anything' on the current system.

However, you need to move the HMI Modbus slave or server driver to port 502. I am not aware of any way to make a Schneider PLC and the comms blocks use a port other than 502. Other platforms, such as some Rockwell controllers, allow much more flexible use of Ethernet through some of their open sockets capabilities.

If you must go down this path, and you really can't change *anything* on the current system, I think you will need some sort of Gateway that will allow communications to this selected port. Redlion comes to mind - I would implement two masters on the Redlion device: one that is reading from the current system on port 8000, then a second instance writing to the M340 on port 502 because the comms blocks in Unity can be painful. However, there are other ways to do this that are perfectly valid.

I think you are right. Because I can read and write data between m340 plcs. When I tried to connect to HMI, It is going down. I saw a forum, s7-200 and m340 are communicating with each other. My big problem is the costumer, doesn't give permission to connect s7-200 plc. Actually they doesn't have program.