Hello Community
I am using an external SSI Absolute Encoder (Kubler F5863.1226.G221 )with an ACOPOS P3 plug‑in module (8EAC0150.001-1). I have completed the wiring and configuration by following the guidelines provided in the Automation Studio help.
However, when I check the NC trace, the position value remains constant and does not change.
What can be the possible issue in this case?
Hi Priyank,
Hello and welcome to the Community!
This is just off the top of my head, but I did some testing with an external encoder a while back and I ran into the same issue until the axis was powered on. Are you able to power on your axis and then re-run your test to see if the position changes?
Hi Priyank,
welcome to the community!
There could be many reasons for the problem, of course. To help us to identify the reason, could you share the following:
From my experience with SSI and Biss encoders, there are two very common reasons for problems:
Pleas doublecheck and send us the configuration infos.
Hi @kuma1p ,
Could you share with us your configuration inside AS?
Is this your encoder?
How did you make the cable?
If you home the axis with the mode direct did you get any error?
Thanks
Ciao
Valerio
With this configuration, you need an external supply voltage for the encoder. You will get NO Voltage out of Pin 1 and 7 of the 8EAC0150. Do you have external supply voltage for the encoder? The other values in your configuration seem to be ok.
You could trace the ParID 246 ENCOD2_POS_ACT. This is the encoder raw value (increments) in one revolution. There you should see the 12 bit singleturn.
In your trace the Actual Speed seems to make some noise. The reason is maybe because of the PCTRL actually uses Encoder 1 and not Encoder 2. I think ParID 230 PCTRL_S_ACT_PARID is not switched from encoder 1 to encoder 2. You can do this later here:
But independent of this: If the encoder works correct, you shout see a position in the Encoder 2 actual position (423 ENCOD2_S_ACT). So this is not the root cause for your problem.
Everything looks fine in the configuration in Automation Studio.
Therefore, all I can do at the moment is to recommend to check the following:
What you could do in AS/mappCockpit: Check the Network Command Trace/ DriveLog for some errors. But I don’t expect something, you should have seen this already.
And read the ParID 88 ENCOD2_STATUS, maybe there you can see something strange.: B&R Online Help
Ok Samuel. I’ll once again recheck the wiring.
If nothing helps, use an oscilloscope to measure between the encoder and P3. Can you see the clock? Can you see changes in the bit pattern when you turn the encoder by hand and check the power supply?
If I interpret this correct, I see the following:
Hi Kumar
The frequency is close to the limit of 400 kHz, which may already be a problem for the encoder. Could you halve the baud rate as a test so that we can be sure that this is not the cause?
Hi Samuel
You were right, this was an encoder issue. We replaced it with new encoder and everything worked fine.
