Allen-Bradley 1756-DNB to Toyopuc DLNK-S2 DeviceNet Setup

I'm trying to commission a DeviceNet network between a 1756-DNB scanner card and a Toyopuc DLNK-S2 DeviceNet card.

I see both the scanner and DLNK-S2 card in RSNetworx for DeviceNet, but I receive an E#77 fault (I/O size mismatch) when communications are trying to establish.

I configured the I/O parameters on the scanner card to send and receive 60 bytes each, and the DLNK-S2 is setup to send/receive 60 bytes each as well.

Anyone have any ideas on what I might be missing?

Try to open Toyopuck device on rsnetworx for devicenet and pay attention to data size.

see attached file

This is what I meant.

Thanks. Unfortunately, there is no EDS file for the Toyopuc card, so I/O area is empty. I created the I/O parameters to match the settings in the Toypuc PLC (see attached), but RSNetworx warns me that the connection sizes may not match (because the device in RSNetworx has no pre-configured I/O sizes).

Attachments

Forgot attachments.

I would try querying the I/O connection object in the Toyopuc. If they implemented it correctly, it will help you figure out the size of the Polled I/O connection.

The procedure for using RSNetworx and the "Class Instance Editor" to query the size of the Polled I/O Connection object in the slave device is described in RA Knowledgebase Article ID # 24919 (Access Level: Everyone).

I've seen lots of devices where they say "configure this in our software for X bytes" but then forget to say "plus two bytes for a header, if you've selected the optional DIP switch, and don't forget to cycle power".

Ken,

You hit the nail on the head. I used a previous post of yours (found through google) to query the device:

"
For a Polled I/O connection, the C/I/A values are Class 0x05 (Connection), Instance 0x02 (Polled), Attributes 7 and 8 (Produced and Consumed sizes)."

It turns out the Toyopuc card was sending 60 bytes, but only receiving 40 (still not sure why, since the card was set for 60/60).

Once I re-configured the polled I/O on the scanner, I was all set.

Thanks so much!

Regards,

Jason

Sweet ! Thanks for posting the followup.

The old "query the connection object" trick still works with Ethernet stuff these days; I helped a co-worker figure out a B&R X20 connection that way a couple of weeks ago.

On topics like this I've reached the point where Googling the problem results in my own solutions, so I think I'd better move on to another topic.