MMC-A4 Plus Excess Error
Dear Expert,
I have 3 real axis connected to Drive. Let say Main Axis, Feednip and Transfer Axis.
Recently and become often the machine stop because of Axis Fault. When I go deeper found that Excess Error are the source of error. This error sometime happened at the same time, sometime only in Main Axis or Main Axis and Feednip.
We have replace the power supply both for MMC and for I/O Blocks (while Power supply 5 Vdc for Encoder emulator from Servo drive to MMC not yet replaced). From electrical perspective what can be the source of problem here.
regards
dedi bin mulyadin
Comments & Answers
Sam Harris said ...
Excess error is caused when the motor does not keep up with the command.
If the axis are electronically geared check master encoder not slipping and has stable signal .
Since the error is random on all axis is there a noise disturbance coupled into the analog ground from the drives?
If the ground of the MMC is not at the same potential as the drives noise can couple into the ground of the analog convertor.
Check te ensure drives are bonded to the control panel and DC common and ground of drives are connected to single point.
Make sure motor armature cables are secured in the ground clamp.
bin mulyadin said ...
Thank You Sir,
Please find my comment
1. If the axis are electronically geared check master encoder not slipping and has stable signal .
The master encoder is coming from another Inverter (AMK) so I think there will be no slip, but I will check again.
2. Since the error is random on all axis is there a noise disturbance coupled into the analog ground from the drives?I would say it's not random, It's always Main axis but sometime following with other axis for example Main Axis with Axis 2 or Main Axis with Axis 2 and Axis 3. But from the monitoring Axis View List the Position Error only happened at Main Axis, I wonder why Axis 2 or/and Axis have excess error too. I have seen the 24Vdc for Drive supplied internally (from the Rectifier module/one in the most left module), while the analog is coming from MMC to each Drive using D-SUB connector and screeen connected to GND. I don't which one you mean analog ground .
3. Check te ensure drives are bonded to the control panel and DC common and ground of drives are connected to single point.
Ground of MMC and Drive are both connected to GND panel (yellow/green terminal).
I am trying to change the Following Error Limit at the Axis Data but it seems to not working or maybe wrong procedure. Please advice how to make change in Axis Data too.
regards
dedi bin mulyadin
Sam Harris said ...
The following error limit is setup in the servo setup used in the ladder diagram.
The name of the setup function is established by the application developer so I can not state the name but the setup function is generally located to the right of the STRTSRV function. Right click on your servo function and View the function. With the servo function open edit the data, Compile and make function. After the function is made compile and download the ladder diagram.
Sam Harris said ...
The following error limit is setup in the servo setup used in the ladder diagram.
The name of the setup function is established by the application developer so I can not state the name but the setup function is generally located to the right of the STRTSRV function. Right click on your servo function and View the function. With the servo function open edit the data, Compile and make function. After the function is made compile and download the ladder diagram.
bin mulyadin said ...
Dear Experts,
In Axis 1 (main Drive), during speed-up or in steady speed let say 80 %, the following error is not more then 50. But during speed-down from 80 to 30 following error is too high (above 5000). The limit is previously is only 1800, but I increase to 5000 just for troubleshooting but it still happened.
Original setting of Kp is 1001, Ki and Kd is 0.
If I disconnect the motor from the load, everything is fine. I test from 100 to 10 it's fine.
Please advice
dedi bin mulyadin
Thanks to Mr. Sam Haris,
Thanks to Mr. Sam Haris,
I am now able to adjust the Following Error Limit. The error is less often now, but still occure. I am afraid if I adjust the limit more higher (originally it is 1800 now it is 5000) will damaging machine.
After monitoring for a while, I see that when thi machine speed down drasticcaly let say from 80% to 30% the following error is high, but when speed up from 30% to 80% they are fine.
Any advice what else should be adjusted in Axis Data
regards
dedi bin mulyadin