CANopen problem

[rzasior]

Hello mates!

I have got a problem with CANopen connection between my Unitronics V560 and gateway Turck BL20-E-GW-CO.
As u see on the picture I attached after connecting my PLC and Turck gateway Err red diode is turned on. 
In this case, user manual says:

"Faulty or interrupted communication between BL20-CANopen gateway and other CANopen.
Possible causes:
– CAN-BusOff
– Heartbeat error
– Guarding error
– Transmit timeout"

"– Check that the fieldbus ends with a termination resistor, if the BL20-CANopen gateway is the last node in the bus topology.
– Check the seating of the CANopen bus connector (or the joints in the case of direct wiring). All connections must be correct and properly seated.
– Check the CANopen cable for possible damage, and for correct connections.
– Check that the correct bit rate has been set.
– Check that the NMT-master is still functioning properly."

 

- I have turned on termination resistor (my gateway is first and the last one at once). I even added extra one to PLC between H and L signal.

- My connectors seats well
- Cables do not have any issues

- Bit rate which I set in "COM PORT INIT" block is the same as in gateway

- My master PLC (V560) works

What can be issue of my problem? How could I cope with that?

Thanks for your time. Cheers!
 

 

[Ausman]

Hi Rzasior,

Others may have suggestions I don't know about, but my immediate thoughts:

 

It looks like you have covered things.  I'm assuming the error led is not on with PLC disconnected and communication not trying.

So time to check it all again!  Easy things first as dumb errors easily missed!

 

560 reports a fault as well?  Com init settings definitely OK? Earthing OK?  Baud rate definitely the same?  Polarity correct?  Electrically checked all connections are ok?  H&L correct at the Turck...not spaced apart over the terminal block, (although it shouldn't matter)? Tried altering the Turck address to one either side of what it is meant to be via the DIPs in case they have some strange numbering quirk?

Also, although it shouldn't matter in the slightest, I always have all control gear running from the same phase.

 

If again all ok but still the error, I would first be playing the "vary the baud rate" game.  Set the Turck to the lowest it can go which is one above the 560's minimum of 10Kb, the info sheet I googled says 20Kb is lowest.  Start the 560 at 10Kb and increase it a step at a time and see if the connection picks up.  If it doesn't, vary the Turck and repeat.  I would always be trying the slower speeds first.  Maybe the Turck DIPS are not working ok.  I don't know this particular unit, but I have had manuals where the information is incorrect and the DIPs are actually inverse in operation.  Although the speed game is a pain, it is not that hard to do and I have sometimes picked up a dud connection with surprising implications.  If still no go, I would be taking the PLC physically right next to the Turck and hook in with minimal cable length.  If it works then that will help as it must be a cabling issue.

 

If none of this helps then time for some more headscratching and input from someone here with more knowledge.

 

cheers,

 

Aus

[rzasior]

>> 560 reports a fault as well?

 

SI 236 shows error "6", that's mean that I have:

CANbus Warning error

Poor transmission quality due to faulty wiring, or if the cable length exceeds recommendations.

 

 

&

One or more networked units cannot be read. If this bit is ON, check SI 238, SI 240-243.

 

SOURCE: http://www.unitronics.com/knowledgebase/visilogic/knowledgebase/visilogic/Communications/Networks/CANbus_network_problems.htm
 

>> Com init settings definitely OK? Baud rate definitely the same?
 

Yes. My DIP switches are 0 1 1, so my gateway is set also as 20 Kb

 

 

Earthing OK?

 

Yes. It is.

 

Polarity correct?

 

I think so. 

V- is grey one, V+ is a black one.

 

 

Electrically checked all connections are ok?

 

Yes, they are.

 

Tried altering the Turck address to one either side of what it is meant to be via the DIPs in case they have some strange numbering quirk?

 

If You ask if I tried different gateway IDs - yes, I tried to connect devices using different adresses, but nothing happened.

 

I also tried to run it on lowest rate, but also there happened nothing.

 

Additional informations:

- I tried to put extra resistor between H & L at PLC but nothing happened. (Btw. CANbus network termination resistor is in V560 standard kit contents, so it shouldn't be neccesarry I think. Or maybe i have to turn it on manually?

 

- I also tried to make as short cables as possible. Nothing happened

Thank You for your help, I appreciate it a lot, but maybe You have any idea of another solutions?

Cheers, Rzasior.

 

 

 

 

 

[Ausman]

Baud rate definitely the same?

 

Yes. My DIP switches are 0 1 1, so my gateway is set also as 20 Kb

 

Hi again,

 

Yep...s/t not right somewhere.  In relation to the above, in theory the Turck is set at 20Kb.  Did you then run the PLC at all it's different baud rates to check if it connected at another speed?  This is not clear from your answer.   This is a long shot but s/t worth trying if you haven't done so already.

 

Also, pls post a screen shot of your Com init settings, a pic of your connections at the Turck, and pls "label" the leads shown in the pic of the PLC connector. 

 

 

cheers,

 

Aus

[rzasior]

>> Did you then run the PLC at all it's different baud rates to check if it connected at another speed?

 

Yes. I tried all options.

>> Also, pls post a screen shot of your Com init settings, a pic of your connections at the Turck, and pls "label" the leads shown in the pic of the PLC connector. 

 

Ok. I did it.

 

BTW. SI 236 (CANbus network communication error) shows me value "6". It means that:

"Poor transmission quality due to faulty wiring, or if the cable length exceeds recommendations."

 

and

 

One or more networked units cannot be read. If this bit is ON, check SI 238, SI 240-243."

 

How is that possible when I'm using reccomended DeviceNet cable?

 

Cheers, Rzasior

 

 

 

 

 

 

 

 

 

 

 

photo upload

[Ausman]

Hi again,

thanks for these.  There is still a simple explanation for this somewhere, but it is hard to see without being there! 

 

The only thing that stands out in the photos is perhaps some earthing issues.  I can't see them being the cause, but worth doing just in case.  There is no earth at the PLC and perhaps the comms line is earthed at both ends if the blue lead going to the lower Turck earth IS an extension of the earth. Another thing is to check that there isn't some sort of residual crap in the push connector sockets that is preventing contact.

 

I've assumed all along, here, that it is wiring, but perhaps there is a PLC program issue.  My read of the Turck manual is that you have the address set to 2.  No clash with the PLC? If you've used the Canopen example in Visi, the PLC is at 2.  Haven't accidentally left it at that? 

 

If you haven't seen the example yet, have a good look at it's structure. 

 

That's all I can offer at present.  Others here have far more experience than me with Canopen.

 

cheers,

Aus

[tmoulder]

I'm going to throw a really stupid idea out here:

 

Some models of unitronics label the terminals for the can port, and some do not.  The diagram you posted from the documentation, and the image you took and labelled, is in reverse order.

 

Top to bottom, on a V570 (where the terminals are marked on the side of the PLC), the terminals are V+, H, PE, L, V-

 

This has gotten me more than once.  

 

Best of Luck!

[Ausman]

Hi & thanks Tm,

 

yep I thought of this one and I agree.  But I don't have a correct unit to physically check but did look very carefully at the slots on the connector, (not the rounds) compared them to some of mine on other models, and thought that everything looked OK.  (Surely Unitronics aren't inverting something this fundamental b/n different models?) But yeah, double check them again Rzasior.  Unless it is a program issue, there is likely something really simple here that would be obvious if on site!  I really hope this is it.....I should have mentioned to check it again.

 

Keep hunting, Rzas!

 

cheers,

Aus