Pause or Stop encoder count during jog?

[eddy159357]

Hi, I'm programming in RSLogix 500, and I'm wondering how I would program a Jog command that does not increase the encoder count. Basically we'd like to be able to jog to adjust a piece without messing up the existing counter.

My first thought would be to mov the encoder count into a float before the jog and then mov it back into the HSC after the jog is complete?

 

[MikeyN]

It is best to keep the HSC on an unconditional rung to prevent losing counts during operation. It sounds like you are wanting to lose counts while jogging, so why not put an XIO or XIC in front of the HSC to disable it while in jog mode? The ACC value of the HSC is read only, so you can't MOV a value back into it. Also, why would you move it to a float? IIRC the PRE and ACC are integers only.

 

[eddy159357]

Thanks, that is a good idea! Yes sorry, not a float the counts are integer.

So, I currently do not have a rung that enables the HSC, it's enabled in the function files. Would I move a bit to HSC:0.CE or FE to turn it off while I'm jogging?

It is best to keep the HSC on an unconditional rung to prevent losing counts during operation. It sounds like you are wanting to lose counts while jogging, so why not put an XIO or XIC in front of the HSC to disable it while in jog mode? The ACC value of the HSC is read only, so you can't MOV a value back into it. Also, why would you move it to a float? IIRC the PRE and ACC are integers only.

 

[MikeyN]

Ah, you are using a MicroLogix. I am more familiar with SLC and using the HSC instruction. I would imagine you can set the .CE bit to 0 while you are jogging.

If you have a TechConnect contract, check out this article: ID: QA1634 | Access Levels: TechConnect. It has a very handy document attached that I think will explain what you are trying to do.