Kinetix5500 Not Synchronized!

[PLC Pie Guy]

Hey Folks.

L33ERM, V33.12

I'm having an issue with a machine that I built.
I converted a an old 4 headed Pneumatic Filler to Servo with a set of AB Servo motors and Tolomatic, ball screw linear actuators.

The machine itself works perfectly and until we took it to test in production, it was flawless. So we have it all ready in the production schedule and we put it in place. I power it up and immediately notice that I cant home any of my axis.

I connect my computer and quickly find that there is a "Not Synchronized" on my Group Status tab. I ended up pulling the machine from production and putting it back in the shop a bit digested with the whole situation.....


Now this AM, back in the shop. I power the machine up to find the exact same situation. So I power cycle it again and the same issue, not synchronized. This time I download, it works perfectly, can home after the download.

So I power cycle it again. After the 3 successful power cycle and re-homing, another power cycle gets me back to the Not Synchronized issue. There seems to be no rhyme or reason to when it happens, its just random. Of course it would happen when all the folks are there to get trained on the new machine.... They think its a POS now and haven't even seen it run.


Any suggestions on what could be causing this Group Not Synchronized Issue or how to rectify?

I will say, that I have my Ethernet connected directly from the first Kinetix to one of the ports on the L33ERM. The first Kinetix jump to the other three from their own ethernet ports.

 

[PLC Pie Guy]

So I finally got to speak with Rockwell tech support.

They talked to me about setting the priorities in the advanced tab of the Date/Time window.

They were set to default, he asked me to try setting these to 1 and 2 and re-try.
I will be back at the machine tomorrow AM and I will follow up here with my results.

They also explained to me how to use the AB:MotionDiagnostics:S:1 tag to help me troubleshoot any further issues should the priority setting not help me.

Thank you.

 

[PLC Pie Guy]

So to continue this.

I downloaded the program with the Date/Time Advanced - Priority set as specified by Rockwell. 1 for priority 1 and 2 for priority 2.

The result is after several power cycles it seems to recover from each one and successfully Synchronize the group.

Each time I go online to verify this this.

After many cycles, 1 time, I noticed that it was taking a very long time to synchronize the group. It did, without intervention, but it took several minutes to normalize.

So I started digging into the AB:Motion_Diagnostics:S:1 tag for each of the 4 Kinetix5500. I noticed that on one of the drives, I have a value of 262 for
SVD004:S.LateControllerToDriveTransmissions. The rest of this tag is all 0 with the exception of the last 5 elements. They all look normal. In the other 3 drives, these values are always all 0.

The drive that is showing this issue, is the first drive in a string of 4. The Ethernet is run directly to the drive from the PLC and from the first drive with very short cables directly to the next one. I tried replacing the main cable between the first drive and the PLC with an AB shielded cable, I get the same result with the SVD004:S.LateControllerToDriveTransmissions = 262.

I have tried unplugging everything else from the processor. (Just PC connected in one port and drives on the other) same result.

I have tried moving the plc connection to the last drive in the string, same result.

I have tried connecting only the drive in question. Same result....

Upon shuffling all this around, I now see a value of 4 in the tag SVD004:S.LateControllerToDriveTransmissions. After a power cycle at this point, it goes back to a value of 250, but the group is synchronized...

I'm not sure what to think about all this. Could the ethernet module be bad or going bad in this new Kinetix5500 and causing these observations?

Thank you.

 

[PLC Pie Guy]

If your following along....

I tried a new drive today. Actually 2 of them. Both with the same results as the first.
I continue to observe the same values as described in the tags in the original post.
The machine is functioning perfectly. I'm just kind of mystified about why I see values in the SVD004:S.LateControllerToDriveTransmissions tag and not 0 like the other 3 drives.

 

[GerryN]

As long as the number doesn't climb during operation I wouldn't worry too much about it.

All the equipment is synchronized to the same course update periods. The controller sends out packets to all the drives at the beginning of the update period. The problem could be due to the controller CPU being busy at initialization and the last drive is receiving it's packet later than expected or it could also be that the clock on that drive is not completely synchronized yet. Note that the crystals that control the clocks are used "raw" initially but there is a tuning algorithm that runs which might take longer on one of the drives because it is the drive with the "worst" crystal. After a short automatic tuning period all the clocks become completely synchronized. Since replacing the drive results in the same issue, the problem is likely that the controller is just a bit too busy during initialization to get the packets out in a timely manner.

 

[dmroeder]

I missed this thread, I sent you a PM @PLC_Pie_Guy