Motion control: MAG to MAM instruction

Hi
I am new to the motion control. We have two kinetix 7000 which are controlled by controllogix 5000.
Both servo drives mostly work fine either on their own or in gear mode but motion needs a little bit of configuration or tuning in one of the movement they are involving. I am using MAG instruction to gear the slave servo drive to the master. I am using 1.15 – 1.2 gear ratio rate according to the positioning in this particular gearing. Slave accelerates and catches the master on move then it needs to break MAG instruction and jumps into MAM instruction. The way the slave makes the jump from one to another the speed goes to half or nearly 0 and then accelerates that’s where I have the problem with. We don’t need a deceleration and acceleration. We just need an acceleration from where MAM instruction started.
I changed Master Reference in MAG from Actual to Command which has been suggested in Rockwell website for smooth move. Then I made acceleration rate same both in MAG and MAM instructions.
And my ideas stop there. I need your suggestions or your experiences in doing the right thing. I think torque value makes this happening but I am still not sure.
I attached the graphics from rslogix5000 showing MAG and MAM *.IP (red and green lines), speed in purple and torque in white
Thanks for your help

In your MAM statement, I believe you want to have

MERGE: Enabled
MERGE SPEED: Current

REVISION: I don't know that the Merge speed matters.

I don't know how your are handling the transition between the MAG and MAM. Not sure if the MAM merge will override the MAG completley or just while moving. I think it may overrride it completely (ie you would not need to have a MAS to stop the MAG). If you do need an MAS, make sure it is only stopping MAG commands and not all commands.

I have

Merge:enabled
Merge speed: programmed

Should I change them?

No, as I think about it, that should be ok.

Are you issuing a MAS command to kill the MAG? I think if Merge is enabled on the MAM, it will overrride and cancel the MAG (Not totally certain).

I'm just guessing that you are telling the MAG to stop (thus it goes to near zero) and then the MAM kicks in.

No I am not using MAS. MAG rung goes to false at some point and where the MAM kicks in. When i zoom that graphic, red line goes to 0 and green line to 1 just after.

The "Rung" going false is irrelevant. A motion command just needs to be activated and will remain "in process" until it completes(like a MAM) or is stopped(MAS) or overrideen by another command. The rung condition is irrelevant once the instruction has been activated.

It may just be a graphing/reporting issue, but I would not expect to see any real time between the MAG.IP and the MAM.IP. If there actually is time between these, I would think that the MAG is stopping. Are you sure there isn't a MAS being activated??

Beyond that, try creating a new MAM with a new MAM Motion control tag. I have had weird problems in the past that were easily solved by making a new instruction and new name (somehow the existing Motion Control tag was inherently corrupted). I think it usually happened when I had copied an instruction from an eisting instruction and then renamed it. Create a new MAM and new name from scratch.

Can you post a picture of your MAM instruction?

MAS only kicks in if the system goes to manual, semi-auto or stop movements involved

It looks to me like the MAM is trying to ramp up from 0 speed at 11:46:5.25 even though the merge is set. It would be good to see the target speed too. I would check for discontinuities in the target speed and position. There shouldn't be any.

The actual speed shouldn't drop like it does unless the target speed is also dropping to 0.

observation: REAL_MOTION[0] suddenly changes. I assume this happens before the MAM is executed b/c the MAM will use the value that is present at the time of execution.

I'd recommend Jerk Units "% of time" and then use accel jerk=100, decel jerk=100.

All in all, it really seems to be acting as if the merge is not there. I agree with Peter that it looks like it is trying to follow a move that starts at zero speed rather than taking over from the current speed. I would not expect that with the Merge enabled. Try the new instruction approach.

I will try the new approach as well as new tag for MAM instruction tomorrow also I will monitor REALMOTION[0].

Thanks for your suggestions. I will let you know of the outcome.

I have made changes one at a time and both at the same time.

"I'd recommend Jerk Units "% of time" and then use accel jerk=100, decel jerk=100" didn,t work, servo stopped completely and caused problems so i changed it back to how it was.

"...try creating a new MAM with a new MAM Motion control tag. I have had weird problems in the past that were easily solved by making a new instruction and new name (somehow the existing Motion Control tag was inherently corrupted). I think it usually happened when I had copied an instruction from an eisting instruction and then renamed it. Create a new MAM and new name from scratch." tried this as well, not much difference. At the beginning i thought the value it was reducing to was higher than before but there were occasions that it was same.

Do your graph again and this time chart:
AX_Puller2.CommandPosition
AX_Puller2.CommandVelocity

(names may not be right, but there are commanded position & velocity tags)