keal

CJ1M-CPU13-ETN modbus

18 posts in this topic

Hello, I want to send information with a CJ1M-CPU13-ETN to a B&R X20CP0484 over ethernet with an open protocol like modbus. It's possible ?

Thank's in advance...

Best regards.

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Hi, I try to do this since 4 days.... Nothing for the moment, if anyone know how to do this (send information with modbus and cx programmer, please help me !)

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Posted (edited)

Hi @keal, unfortunately it's not possible. The said CPU does not support open Socket Service protocol. You can only use it for FINS, web server, or SNTP. It is stated in manual number W441, chapter 1-2.

You need to connect a CJ1W-ETN21 or CJ1W-ETN11 to use Modbus TCP

Edited by innoaloe

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16 hours ago, innoaloe said:

Hi @keal, unfortunately it's not possible. The said CPU does not support open Socket Service protocol. You can only use it for FINS, web server, or SNTP. It is stated in manual number W441, chapter 1-2.

You need to connect a CJ1W-ETN21 or CJ1W-ETN11 to use Modbus TCP

Thank you for your reply, i have see it, but i wanted a confirmation. And it's not possible to use FINS to communicate with a BR automation ?

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Actualy you can, if the BR supports Udp socket. Just open a UDP port on BR side then send data from the omron plc using SEND or RECV instruction.

The down side though, you need to manually process the Fins command sent by omron plc and generate proper fins response also to be sent back.

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I don't find SEND and RECV instruction.

 

And what do you mean by generate proper fins response ? To receive fins command by omron, it's need to send a response ?

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And how i use send and recv ? because, i need to connect to my BR PLC (ip address)

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26 minutes ago, keal said:

I don't find SEND and RECV instruction.

 

And what do you mean by generate proper fins response ? To receive fins command by omron, it's need to send a response ?

Both SEND and RECV instruction is on the Omron PLC side. You can use it on CJ1M-CPU13-ETN also.

You need to read manual number W342 in order to understand the FINS protocol structure and its contents. It will take some time to work on.
Now, if you just need to send information to the BR plc (using the SEND instruction), then the Omron PLC don't need to receive any response, but the BR PLC still need to process the data (like removing FINS protocol headers and just taking the necessary data).

But if you want to receive data from the BR plc (using the RECV instruction), the Omron PLC will send a FINS request first, which must be interpreted by the BR PLC in order to send proper response. And the response must be in correct FINS protocol format also, or else Omron PLC will interpret it as a communication error. This is pretty troublesome to do I'd say, since basically you are creating a protocol manually inside the BR PLC. Buying a CJ1W-ETNX1 slot will make it faster since the Modbus TCP library is already available to use with ease.

 

27 minutes ago, keal said:

And how i use send and recv ? because, i need to connect to my BR PLC (ip address)

The SEND/RECV instructions doesn't require you to input IP Address of the target PLC, since UDP is an unconnected socket communication. But you need to specify Destination Node Address, which is the 4th digit of BR PLCs IP Address, considering both Omron and BR is on a same subnet.
E.g. Omron IP is 192.168.250.1 and BR IP is 192.168.250.5, the Destination Node Address is set to 5 in that instruction.

Still I'd say it's pretty troublesome to do.

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Thank you very much for your help, i'm going to try this... And if i can't, i have two choices, the CJ1W ETN21 or CJ1W SCU21 (to communicate in RS232)

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For you, it's possible to use the built-in peripheral port to communicate in RS232

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13 minutes ago, keal said:

For you, it's possible to use the built-in peripheral port to communicate in RS232

No, that's not possible. See the plc Settings under the peripheral port. You'll see that Rs232 does not exist as an option.

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Yes. Hardware-wise, the connector is indeed RS232C. But software wise, that port can only send certain Omron protocols, like Toolbus (it's default. Also called C-Mode in W342 manual I believe), Host Link, or Serial Gateway. It doesn't support No-Protocol RS-232C.

You can, however, sends the Toolbus command using the very same SEND or RECV instructions to the BR. But then it will be the same issue with the FINS protocol, where the BR plc need to interpret the data

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Hmm ok... So, I think the better way it's to send information with SEND(090) by ethernet and identify the data.

+Have you an example of program that send data with SEND(090), because, when i send with this function block, the led SD don't blink (that i think mean send data)

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Ok, now, i can send with the omron to my PC (multiway) but, in mode "terminal" in sysmac, when i receive the omron tram, there is a message that crash multiway, the datagram is too large to fit into the buffer and is truncated

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The Terminal mode is just your other HyperTerminal like Putty. If you're receiving too many data bytes, try giving a Differential Up to the SEND Instruction, so it should be executed only once on each trigger.

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