how do I teach Kinetix the home position?

I am studying motion control with RSLogix5K & Kinetix 6500. I know I use MAH to home an axis. But how do I teach Kinetix the home position? I can use a photo eye to send a high signal, but where to? Is there a servo drive structured (module-defined) output tag that I can use? Or do I have to use the CIP type MSG method? Thanks.

Hi

The home sensor is wired into the drive. In the mah instruction there is a couple of options in the drop down box, as well as direction, speed etc.

Hope this helps you

Donnchadh

You are right that you want to use the MAH instruction. How you have the homing setup for the servo will dictate what that MAH instruction does. In my picture that I have attached you can see that I set up my homing on a switch. When the MAH is activated the servo will drive at 2mm/s until the switch is made, and then drive in the other direction at 5.0mm/s to an offset of 25mm off of the switch. This is now the servos zero. This works for both incremental and absolute servos.

Unfortunately, this is not all there is to it if you have absolute encoders. When power is cycled on the machine you will lose this home position. With absolute encoders you also have to run the MAH instruction with your homing mode set to "Absolute". This instruction will not move the servo, but simply take its current position and then make that your absolute zero position. Now if you power cycle the machine the position is remembered, and you shouldn't have to home the servos. So what I like to do is set my servo to an active homing mode to find my zero. I then use the SSV instructions to set the mode to absolute, and then activate the MAH again. You can see this in my other attached image. In a small homing sequence I set the system values for homing, and then I use the GSV function to back check that the values took. Then I retrigger the MAH.

I hope this helps you out

I suppose I went a little off topic. Here is a snippet of a Kinetix 6000 drive with the home limit switch wired to it. This should clear your question up directly. We used a limit switch, but a photo eye would work here too.

JDCROCKETT724 said:

I suppose I went a little off topic. Here is a snippet of a Kinetix 6000 drive with the home limit switch wired to it. This should clear your question up directly. We used a limit switch, but a photo eye would work here too.

Click to expand...

That surely answers my question and your other reply was priceless too. Thanks JDCROCKETT. Would you give me any link or suggestions for learning servo drive motion control programming (with Controllogix)?