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• To terminate the weld by collapse distance, the total distance the carriage travels from the
Dynamic Trigger Switch (TRS) to a preset lower limit position
2.2.6 Upper Limit Switch
The optical Upper Limit Switch (ULS) signals the control circuits in the controller that the
carriage has returned to the top of its stroke and the welder is ready to start another weld
cycle.
The controller uses this ULS signal to perform various control functions. For example:
• Indexing control, in automated systems, the Ready signal developed by the controller after the
ULS is activated can be used by external devices to prevent movement of the material handling
equipment (indexing) when the horn is not fully retracted
• Electronic pretriggering, the controller can use the ULS signal to activate ultrasonic energy before
the horn contacts the workpiece. Pretriggering is used with large of difficult-to-start horns and in
a variety of applications
2.2.7 User I/O Connector
External controls and devices, such as ALARMS, WELD ON and EXTERNAL RESET signals,
are available through +24V DC interface on the back panel of the welder. In addition, a
READY signal is available as both +24V DC and isolated contact closure. Using this
interface, selected faults or weld errors sensed by the welder can be communicated
outside the welder for monitoring cycles and sorting suspect workpieces.
2.2.8 Dynamic Triggering and Follow-Through
Many weld applications require that force be applied to the workpiece before ultrasonic
energy is activated. To achieve this, the welder contains a Dynamic Triggering Mechanism,
located between the air cylinder and the carriage. The Dynamic Triggering Mechanism
initiates (triggers) ultrasonic energy after a preset force is applied to the workpiece.
Dynamic follow-through maintains a consistent force on the workpiece during the weld
collapse. The system helps provide uniform weld quality.
The calibrated TRIGGER PRESSURE control, located on the front panel, allows you to
record and duplicate the dynamic triggering force.