Touch probe (capturing machine position)

[bbay]

Hello!

 

Does anyone have experience using a touch probe to capture machine position?

 

I have a Renishaw OMP400, OMM-2, and OSI wired to a Power PMAC through the ACC65E digital I/O card.

 

I intend for the PMAC to record position, halt motion, and move back upon probe trigger.

 

My attempts to use "software capture" triggered moves (e.g. X50^-50) have failed, likely because it was misread as overtravel.

 

Is there a way to use hardware/software capture without disabling overtravel protection? Might it be simpler, albeit less accurate, to implement manually through a PLC? E.g. a while loop that checks for the triggered input.

 

The machine is a 3-axis parallel manipulator (tri-pyramid robot).

 

 

 

My current procedure runs a plc with the following for each motor, before executing the rapid trigger move:

Motor[ii].pCaptFlag = ACC65E… // Capture when probe triggers

Motor[ii].CaptFlagBit = 2 // Probe bit

Motor[ii].captureMode = 1; // Software capture, input triggering

Motor[ii].RapidSpeedSel = 0; // Peak velocity is now Motor[x].JogSpeed

Motor[ii].JogSpeed = very low // Speed at which probe will approach part

[Richard Naddaf]

Why not wire this into a user flag (high speed input) and use hardware capture instead?

Yes, you should be able to do all this programmatically without having to disable the overtravel limits.