Ethernet IP addressing

[sgull]

Hi

 

I am trying to read from energy meter (Socomec DIRIS A40) to a unistream via MODBUS TCP.

I have set up the device as per the images.

I can access the meters built in webserver while connected to the same hub as the PLC so the addressing and cabling appears ok.

The result returned for each parameter is 0.

I think it may be an addressing issue but I am not sure what to try next.

 

Regards

Denis

 

536181B_GB_Ethernet-1.pdf

[Ausman]

Perhaps the webserver is on a different port?  Can you go further into the settings of the meter to check this?  Many things I encounter like this often use ports either side of the designated one, and you have to allow for them.  Whilst connected to the meter on a PC, use something like TcpView to see what else it might be throwing up.  One species of cameras I run use 5 sequential ports based around the designated one, but only 2 of them relate to successful operation via the outside world.  But there is no mention of this quirk in any manual...I just found it by observing port activity.

cheers, Aus

[sgull]

Thanks Aus

Im using port 502 for the Modbus TCP.

I cant find anything in the manual or online to suggest a different port.

I will try playing around with different values to see if I can get a response.

Regards

Denis

 

[Joe Tauser]

Try subtracting 40000 from your addresses.

Holding register data types already imply a 4xxxx base address, and I think you should start at 10512.

Also, the document shows the data is two words long, so change your receiving tag data types to INT32.

You may be off by one, also.  If subtracting 40000 results in weird values try subtracting 40001.

Joe T.

[sgull]

Thanks Joe

I already tried subtracting the 40000 but didnt try the offset of 1.

I will try this and post back any results.

Regards

Denis

 

[Ausman]

Hi Denis,

at this stage it would be much easier to use Modbus Poll etc on your PC to throw things at the meter to find what works.  Once you get responses you could transpose things into plc language, or if that doesn't work then monitor the port whilst in action to fully find all the data stream needed.

cheers,

Aus

[sgull]

Had a quick look at this again today.

I got communicating using the settings above but with INT32 instead of INT16 (thanks Joe)

The results I am getting are really big numbers, much higher than what I would expect.

I will now need to find out which parts of the result need to be swapped to give me the correct result.

The documentation of the meter is quite poor on this topic.

Thanks for all the help.