Hi Guys been a long time browser of these forums and they have helped me an incredible amount, however I currently have an issue that I can't seem to find any info on (even tech support couldn't really help)
Firstly I'll give an overview of the application, we have a filling machine, one motor drives the "turret" of the filling machine, we then had a normal three phase motor that would drive the dosing system. To keep these in time some very antiquated hardware would adjust a 0-10v signal to an inverter to keep a flag appearing in a set window. we have two of these machines
I then built a temporary rig to modify the machinery the hardware consists of:
1756 L61 cpu version 19.11
1756 M03SE version 19
2094-bc02-m02-s servo drive
Multi turn high resolution servo and encoder.
I have mounted the encoder on a shaft connected to the turret, then via use of a MAPC instruction I have the servo motor driving the dosing in time with the turret. I am using a linear cam profile from 0-360, with a master lock position of 287 (this is the controlled stop for the dosing)
Now this works perfectly fine with absolutely no issues what so ever.
So we have gone ahead and ordered the following
1756 L71 version 24
1756 M03SE version 19
2094-bc02-m02-s servo drive
Multi turn high resolution servo and encoder.
Panelview plus 7
So I copied the program over, changed cpu and version etc etc. Intalled this to the second machine (this has slightly different stop positions) and I now have a very strange issue.
When the panel is powered down and back on, and the MAPC is executed the servo drive trips on either overspeed fault or position error. After trying almost everything I could think of I wired a second encoder off the machine and turned this by hand to see where the fault was happening.
It turns out that even though I have the Master lock position set to the current position of the servo (under normal conditions this is 302) it will attempt to lock the cam profile as soon as the encoder hits 0 degrees, therefore instructing the servo to move all the way to 0 and causing the above errors.
now for the really weird part, the encoder is holding its position after power up perfectly, but if I home the encoder (no change to the position reading as its always spot on) then it will run with absolutely no issues at all, until it is powered down and back up.
Ideally I would like to sort the above issue out, however I have though of a work around but I'm not entirely sure how to implement it, what I would like to do is, read the position of the encoder after power up, then use this position as a home offset and then perform a home, this way it retains its position, but will be homed and wont cause any issues, but the only place that I have seen the homing offset is in the homing tab, and I would need to be able to dynamically change this value depending on the encoder position on power up.
Hopefully that makes sense, and someone could give me a bit of guidance I cant upload the program as its over the limit, but if someone has a trusted site I can upload to I would be happy to.
many thanks in advance
Rhys
Firstly I'll give an overview of the application, we have a filling machine, one motor drives the "turret" of the filling machine, we then had a normal three phase motor that would drive the dosing system. To keep these in time some very antiquated hardware would adjust a 0-10v signal to an inverter to keep a flag appearing in a set window. we have two of these machines
I then built a temporary rig to modify the machinery the hardware consists of:
1756 L61 cpu version 19.11
1756 M03SE version 19
2094-bc02-m02-s servo drive
Multi turn high resolution servo and encoder.
I have mounted the encoder on a shaft connected to the turret, then via use of a MAPC instruction I have the servo motor driving the dosing in time with the turret. I am using a linear cam profile from 0-360, with a master lock position of 287 (this is the controlled stop for the dosing)
Now this works perfectly fine with absolutely no issues what so ever.
So we have gone ahead and ordered the following
1756 L71 version 24
1756 M03SE version 19
2094-bc02-m02-s servo drive
Multi turn high resolution servo and encoder.
Panelview plus 7
So I copied the program over, changed cpu and version etc etc. Intalled this to the second machine (this has slightly different stop positions) and I now have a very strange issue.
When the panel is powered down and back on, and the MAPC is executed the servo drive trips on either overspeed fault or position error. After trying almost everything I could think of I wired a second encoder off the machine and turned this by hand to see where the fault was happening.
It turns out that even though I have the Master lock position set to the current position of the servo (under normal conditions this is 302) it will attempt to lock the cam profile as soon as the encoder hits 0 degrees, therefore instructing the servo to move all the way to 0 and causing the above errors.
now for the really weird part, the encoder is holding its position after power up perfectly, but if I home the encoder (no change to the position reading as its always spot on) then it will run with absolutely no issues at all, until it is powered down and back up.
Ideally I would like to sort the above issue out, however I have though of a work around but I'm not entirely sure how to implement it, what I would like to do is, read the position of the encoder after power up, then use this position as a home offset and then perform a home, this way it retains its position, but will be homed and wont cause any issues, but the only place that I have seen the homing offset is in the homing tab, and I would need to be able to dynamically change this value depending on the encoder position on power up.
Hopefully that makes sense, and someone could give me a bit of guidance I cant upload the program as its over the limit, but if someone has a trusted site I can upload to I would be happy to.
many thanks in advance
Rhys