-251723760 CIP Error when trying to read and array of sgl from and AB ControlLogix PLC

[aetc]

I have the NI Ethernet/IP module to communicate with an Allen-Bradley ControlLogix PLC. I am doing both reading (only 13 values) and writing (over 200 values). I am using the basic ethernetip tag write.vi to  do the writing. These program are in an executable running on a 'run-time' machine. I have the list of tagnames I am reading and writing to and have confirmed with the person who created the AB load that the array I am writing to on the AB side has more than enough addresses (it is an array of length 300). However I am only able to write 118 values to it. When trying to write 119 or more I get the error:

-251723760 CIP error - extended status may be available

I have confirmed with NI OPC Servers with an OPC quick client (running on my development PC) connected to the AB ControlLogix that the values I am writing to up to element 118 are getting through correctly, i.e. if I write 123.456 to sample_array[13] then I in fact see this same value at that location in the OPC quick client.

To be honest I am a little disappointed that the error message is so cryptic and gives no hints as to what troubleshooting paths are possible. I have tried various combinations of group/tag names with and w/o offsets, e.g. [3], but nothing has led me any further.

[Jesse_D]

Hi aetc, 

Can you post your code with the problem configuration saved as the default values? 

The size of Explicit (Tag read-write) data that can be transferred is ~504 bytes, I would bet that you are exceeding this limit. We have hit this limit before on Rockwell PLCs.

Does the error message have an extended status associated with it? 

[aetc]

Thanks for the quick response - here are screenshots of before (write OK - writing 118 values - all except last are 0) and after (error - when trying to write an array of length 119) as well as the simple test program I as using.

[Jesse_D]

Writing a 119 length REAL should correspond to 476 bytes worth of data. Including headers I bet you are hitting the size limit of the tag transfer. The limit is a PLC limitation and should be documented somewhere in the Rockwell documents. I can't find the Rockwell documents but I did find this discussion backing up the size conclusion. 

If size is a problem you will just need to do multiple reads/writes. You should be able to read and write to multiple tags in parallel though. 

[aetc]

Thanks - I am in fact assuming there is a size limitation and am splitting up the writes into chunks that would fit within that limitation.

[aetc]

Thanks - I am in fact assuming there is a size limitation and am splitting up the writes into chunks that would fit within that limitation.

[DarkLordOfG]

Did you ever resolve this?  We are getting the same error and we are just trying to read a single value.

John

[Jesse_D]

John, 

Look at the error message. Is it just "Ethernet/IP Industrial Protocol: (Hex 0xF0FF0010) CIP Error - Extended status may be available" or is there more? 

CIP has a setup for extended status that the vendor defines, essentially vendor specific error codes. It may help in this case. 

[DarkLordOfG]

Jesse,

Yes that is the error.  So does this mean it is a setting on the Allen Bradley side?  I am not that familiar with their technology.

John

[Esteban.R]

Hi rammer

Probably the problem is with the configuration, so in order to find out the problem  we will need to know

The extended codes and figure out what they mean and what they do.

Check the configuration on both the LabVIEW side and in the PLC side. The assembly that you are trying to read must set to be the same on both sides.

Are you using explicit reads and writes? The implicit requires that the entire array is read.

Which programming environment are you suing to program the PLC? Could you give us more information about how the AB PLC is setup?

Regards

Esteban R.