Touch Sensing with OTC

Yaskawa America has released a digital interface with the OTC power source. The OTC interface does not support signals for touch sensing function. Therefore, an external source is needed to apply a search voltage and detect when the circuit closes (wire touches). The ComArc LV seamtracking box has a 48vdc circuit for searching voltage and a Hall Effect sensor for current feedback for seamtracking. In this application, the Hall Effect sensor with lugs for the torch lead is not used.

The ComArc LV box has 4 small wire terminals for the external 48 vdc Touch Sense circuit. There is a relay that closes when the SRCH instruction executes and applies 48vdc between the + (torch) and – (work) terminals. There are secondary contacts on a normally closed relay that Open when the search voltage is applied (SE1 and SE2). The wiring back to the YRC1000 controller includes and output which turns on during the SRCH instruction to activate the voltage (via Concurrent IO logic and Simple Connect selection of 48 v Touch Sense option). There is also wiring into Rapid Input 3 (RIN 3) on the Safety IO board. This is standard wiring for the Touch Sense option and should follow system prints, This document covers the external wiring of the ComArc LV box to the OTC welding equipment.

See the document attached for implementation and wiring notes.