Controllogix Motion Phasing Question

Hi guys,
When doing error correction/phasing on top of a MAPC (position) cam based on the Slave.RegistrationPosition, what is the difference between a MAM type 6 (incremental master offset) and a MAM type 1 (incremental move) on the slave?
The 1756-um001 doesn't clearly define the difference, other than showing an X-Y graph that illustrates a type 6 MAM as shifting the profile along the (master) X-axis, while the type 1 is shifted up or down the (slave) y-axis.
In a couple of places a type 1 is used as an example over either an electronic gear or cam for phase control, but type 6 is listed as an alternative. I'm just wondering if anyone has used both in practice, and can give me some pros/cons of each approach.

Thanks,
Dustin

They are different (duh that's why they have the option)

Best way describe the difference is to show an example of each.

EG 1
If the master and slave axes are both rotary axes and moving at the same speed AND all you are trying to do is change the phase then either MAM type will work (this effectively changes the "gear tooth" that is engaged)


EG 2
If the slave axis MAPC CAM has a dwell (axis stationary) in its profile then the MAM will have different effects.

MAM type 1 will cause the slave axis to pause at a different angle ( ie a different gear tooth at top dead center)
MAM type 6 will cause the slave axis to pause at the same angle as before but will start its movement at a different location on the master axis.


Notes:
Lots of assumptions in the descriptions - waiting for questions to clear them up
When I engage MAPC I use the type 6 to change the phase.

If I have used MAG (or a MAPC that is effectively a MAG) then type 1 and type 6 will change phase

The above discussion is using rotary axes.
Try describing a linear slave axis example.

Thanks for the reply. In my situation, both axes are rotary, at same speed, and have no dwell, direction change, or indexing. It is basically a 1:1 gear run cam, with a 2:1 start cam executed once (with a retained Master Lock Position).

After talking with AB Tech Support, it appears that your "EG1" applies in this situation. In practice, I can't find any difference in performance between the two Move Types.

The "EG2" explanation clears up the graph from the AB ref, thanks. Would you say that in a dwell or indexing cam, that a MAM type 1 is a "shorter or longer" adjustment, while a MAM type 6 is a "earlier or later" adjustment?

bmacattack33 said:

MAM type 1 is a "shorter or longer" adjustment,

Click to expand...

Depends on the mechanics of the slave axis - I think of it as a start position change and the CAM scaling defines the "shorter or longer"

bmacattack33 said:

MAM type 6 is a "earlier or later" adjustment?

Click to expand...

Yes

bmacattack33 said:

In my situation, both axes are rotary, at same speed, and have no dwell, direction change, or indexing.

Click to expand...

In applications that I have developed in that situation I recommend that you think about using MAG to "Lock" the axes together then use a MAPC
with the master length fixed at one cycle length and the slave length the phase offset - Benefit: the slave axis phase change occurs over a cycle length reducing the Accel and decel requirements on the slave axis.

In a recent project I just changed the MAG ratio all the time (Clutch engaged) as the cycle length was continuously changing and I was chasing slipping product on a belt.