Ethernet/IP Scanner AB7670-F adds 4 first bytes in Output


#1

Hello,

I’m using an Anybus X-Gateway (AB7670-F) for communicating to an Omron PLC in the Ethernet/IP scanner side of the gateway.

Now it’s working perfectly well, but I had to add 4 bytes more in the Input part of the Omron PLC.

Let me show you in detail.

I configured the following in the Configuration Manager (I disabled the “Control Word/Status word” in Anybus Configuration Manager):

And, in the Web Browser, the connection with the PLC:

Finally, in the Omron Configurator (6 bytes in the Input and 2 bytes in the Output to communicate)

I couldn’t see in the manual information about this 4 first bytes you must to add to communicate well.

I can watch in the PLC memory that the first bit in the first byte shows the operational mode (0: idle, 1: running).

Is it possible to delete this 4 first bytes? How?

Thanks in advance.

Best Regards,
Marc


#2

Hi Marc,

I’m not sure what would be adding 4 bytes. it could possibly be the control word, but this would add two bytes not 4 and from you screen shot I can see this is disabled. The Scanner would only be making the connection as specified in the scan list. Perhaps this is overhead needed by the controller?

Deryck


#4

Hi Deryck,

Thanks for your quick response.

For sure this is not any overhead needed by the controller.

I have tested again but with another EthernetIP device, an Omron remote IO (NX-ECC203) and I have experienced the same issue.

In fact, in this case, this is a problem because as the gateway is adding 4 bytes, I have to connect additional output modules (4 bytes more) to establish the connection.

As I said, I configured 2 “Input I/O data Size” but in Wireshark it appears 8 bytes in the O->T size (I have seen that always there are 2 bytes more in this line, then 6 bytes at the end (4 bytes more of what I configured, AGAIN)).

What would you suggest to do now?

Thanks in advance.

Best regards,
Marc


#5

Hi Mark,

I was trying to setup a demo quickly here to see if i get the same results. I ended up with less time then I expected today.

I’m also checking with my colleagues in Sweden regarding this.

Could you upload the wireshark showing the request for us to take a look at?

Deryck


#6

Hi Deryck,

Thanks for your help.

As I said, now I’m communicating with an Omron Remote IO.

In the slave remote IO, as you can see in Sysmac Studio (Omron Software Configurator), it is configured 12 bytes Input and 6 bytes output, but due to the 4 firsts bytes added by the gateway I can just control from the Profinet Master the last output unit (highlighted).

The configuration in the Anybus Configurator Manager:

The configuration in the Web Browser:

I attach wireshark showing to you the requests from the opening of the connection between x-gateway and the remote IO.

Anybus to Omron NX-EIC203.pcapng (13.0 KB)

The countermeasure I had to take was to add and disable 2 output units (4 bytes in total) in the software. This configuration wouldn’t be necessary if the gateway didn’t add the 4 first byte in the communications.

Here you have the information about the AB7670-F (maybe there is another firmware solving this “issue”).

Anybus%20Information

I expect your feedback.

Thanks in advance.

Marc


#7

Hi Deryck

Do you have any clue?

Thanks.

Marc


#8

It all seems correct, there I/O connection is 2 bytes output and 12 bytes input as you can see in the wireshark:

Input:
image

Output:
image

as you can see, the Run/Idle header is also there, but there are only 2 bytes of output data (I/O data).

Furthermore, We setup an AB7072 as an Ethernet/IP Adapter and then used EIPScan Testtool to setup an I/O connection to the AB7072 (12 Bytes Input and 2 Bytes Output) and the Forward Open from EIPScan Testtool looked exactly the same as from our Scanner.

This proves that our Scanner is setting up a correct I/O connection.

I think it’s 2 bytes of some counter in each direction and 4 bytes Run/Idle header in the Output direction, so the actual size is 8 bytes in the output and 14 bytes in the input), however the raw I/O size (the payload) is still 2 bytes output and 12 bytes input.


#9

Hi Deryck,

My last question to conclude this topic:

Is it possible to delete the 32-bit Run/Idle header in the output direction that it’s adding the AB7670-F? How?

Thanks.

Marc


#10

Hi Marc,

I am double checking, but I do not think this is something we can disable. Support for the run/idle header might be a requirement to be compliant. I would expect the Omron IO device to have an option to enable it, have you reached out to them to check if it is possible?

Deryck


#11

Hello @Marc_Bcn,

I further confirmed that we can not disable the run/idle header from the scanner. Have you been able to talk to Omron regarding enabling the header?

Deryck