Caliper homed with sample in place

Owned by jr_fackler
Feb 18, 2017
2 min read

Status on arrival.

GANTRY software was stopped. The material under observation was left in the tray. After clicking through the messages about obstructions, the calipers went through their homing cycle. Then froze there, no longer responding to Velocity program or Exlar control software commands.

Recovery process, short form

  • Remove power from the Exlar (yellow cables)

  • Pry the calipers apart – 20-30 lb(?) pull against a tensioning spring, assistance required.

  • Remove the section half.

  • Shut down the GANTRY computer. Cycle the power, restart – clears all communication.

  • Start the Exlar software (capital E, dark red).

  • Home tab. Ensure the Auto+home feature is turned off.

  • Export that configuration to the Exlar firmware.

  • Shutdown the Exlar software.

  • Power cycle the Exlar.

Now should be able to open the calipers with the manual button controls.

Once the calipers are open and not obstructing the track, the software may be run normally.

Lagniappe

Turned out to not be germane to the above recovery process, but helpful to know.

The Caliper Exlar is wired to terminate motion on two conditions (not just one as for WRMSL PWL)

  • In current limit

  • When the installed proximity switch is closed (right-hand side of the upper transducer, affixed to the caliper housing)

If the proximity switch is closed, a fault is raised in the Exlar firmware “switch not found”. The fault will not clear until enough physical clearance is achieved to let the switch open.

As a check of communications

There is a spare Exlar in the drawers under the STMSL. Computer communications with the Exlar system can be confirmed by disconnecting the in-place cabling and wiring up the spare

  • Remove power from the Exlar (yellow cable thick)

  • Then remove the button-control cable (black cable thick).

  • Then remove the RS-485 communications cable (black thin).

In reverse of the above order, attach the cables to spare. Beware: The spare may go into motion when power is applied. Totally dependent on settings in firmware last time the device was used. 

Communications control then may be established from the computer via the Exlar software.