MAOC instruction Question

[chantecler 15]

Hi,

I’m writing a program to control a puncher press. Basically the machine has a motorized high inertia flywheel with an 842E-CM single turn encoder directly connected to it. The circular movement is linearized to move a die that punches a steel sheet as the sheet advances under the die. One punch for every flywheel turn.

There are some machine functions that need to be activated and de-activated according to the flywheel position. I have to use the MAOC instruction due to high speed and high precision the process requires.

My problem now is that one particular function has to turn on at 200 degrees (The encoder signal has been scaled to 360.0 degrees) pass the 360.0 or 0.0 degrees point and remain “on” till 10.0 degrees.

So far I have not been able to find a way to do it.

Can somebody help me with that?
 

[Ken Roach 194]

How does it behave when you use 220 as the Start position and 10 as the End position ?

Which execution mode are you using :  "Once", "Continuous", or "Persistent" ?     And what Execution Schedule ?  I would expect bi-directional to work correctly.

My guess is that it's turning on at 220 and off at 360 when it rolls over.

 

[chantecler 15]

I was using persistent and forward only, changed to continuous and bi-directional and it's working perfect.

Thank you very very very much.

I'm going to continue doing some tests cause I need to fully understand this instruction.
 

[kaiser_will 65]

Attached is a brief code & process description of a reference MAOC application.  This process was somewhat similar - rotating drum with ejectors that need to come on at a specific position and only for a brief period of time.  The information and code example may be of use in understanding the motion instruction.

Primer - Bottle Filler - Cam Profile & Ejectors.doc

[chantecler 15]

Thank you Emperor, every help is welcome.

[chantecler 15]

 

I just want to tell that this project materialized and the press has been working fine since startup about six months ago.

I ended up programming two separate MOAC instructions. One I utilize to generate logic bits to synchronize the press with some functions like: servos sheet advance command, product control and die protection, and the press normal stop command. The second MAOC I utilize to drive two physical outputs of my 5069-OBF module, one pushes the product out of the tool and the other expulses the product from the die.

The major problem I faced was how to make the MAOC instruction drive only two physical outputs. Originally I configured the MAOC as in knowledgebase topic 853576. I only wanted bits 4 and 5 of my output module to be driven by the instruction but I got all the other bits to go "false". I struggled with this problem for an hour but since I needed to finish all the programming in a very short time I decided to use a different approach and go back to this issue later on.

The different approach was to configure the Module's Output Data as "Data" (not scheduled) and drive bits 4 and 5 from my press task. The press task was configured to run every 2 msec so I estimated that this would introduce an error of 2.4 degrees while running at 200 struck/min. Fortunately this turned out to be completely tolerable.

I haven't gone back to this issue so far since I need production to stop and there is no hurry to do so.

Finally my question:   Has anybody had this same issue with a 5069 CompactLogix?      Ideas?

Thank you

Edited 20 Feb 2019 by chantecler