WesleyVdB

I have Tia Portal V16 and I'm upgrading an older machine.
The machine has still the old I/o cards on an ET200 profibus island connect to a new plc.

The rsr232 is through CP 340 RS232C.

Is it safe to assume that you are upgrading the CPU to an S7-1500?

If so, I fear you are out of luck as CP340's are NOT supported by S7-1500's, see also ChristophD's advice in THIS post for more.

Hello,

if I could say my opinion although fritz is right. I don't understand your actual HW stations types and their interconnections because somehow I understand your situation like this. If your new CPU is connected to ET200 DP station, there can't be S7-300 module to it attached logically. This can means that also some other distribution module with S7 rack type is attached to ET200 and then I expect this ET200 as CPU. If this is that case you can maybe control this data exchange on CP340 with new CPU to send some user defined commands via network to ET200 CPU and then internally do jobs as are required. I think that this can work without problems in case that all old systems need to be existed still via some important reason 

Hello,

AutoGen_3500051

Hello,

Can I have some help?

I have S7-315-2 DP, CP340 and I want to control Delta VFD via RS485 and MODBUS.

How can I send motor data? I am trying P_Send but not sure of which data to send and how to read the feedback.

Thank you in advance.

you need understand for first that your CP340 doesn't support Modbus RTU. You have 2 choices:

1. create your own Modbus driver/messages with P_blocks. Of course, very good Modbus RTU knowledge is expected here.

2. check some 3-rd party library from our member Tibi68, it is library that can be used with also CP340 CP and without dongle. It is simply library/driver and is available somewhere on this Forum.

Hello;

I would like to add a few deas to Ivan's very correct answer.

Siemens does not support a CP 340 as a Modbus master (the CPU is generally a Modbus master when connecting to a drive). Siemens has a loadble Modbus driver for a CP 341, but considers the CP 340 too primitive for Modbus exchanges.

As staed by Ivan, member TI58 developped a block of functions that allows a CP 340 to act as a Modbus master, and posted it here so anyone could upload and use it. You will find it on this link:

https://support.industry.siemens.com/forum/ca/en/posts/modbus-rtu-master-for-cp340-341-441-x-(no-dongle-required)/111091

Since it was not developped by Siemens engineers and does not follow the Siemens software standards, this program is not supported by Siemens. Tibi58 hosted questions on his program for a few years to provide help, on the same link, but he is not so active on  the forum now. You will have to go though the discussion on the blocks to find out how to debug them if you have problems . Many users have found them easy to integrate in their PLC program over the years, so you should not have much trouble.

With these functions the CP 340 acts as a Modbus master, so your VFD must act as a Modbus slave. That means that you must have the Modbus mapping (list of registers that you will need to read/write from the master in order to command and configure it)and operating instructions for that drive. Do you have these? If you do not, and tell us the make and model of VFD you plan to control, we might be able to locate them for you.

Hope this helps,

Daniel Chartier