Machine I/O

The 44-way (high density) socket provides connection for the CMM I/O.

The table below details the I/O pinout:

+24 Vdc

+24 Vdc limited to 1 A.

Air

Pin 2 will be be set low (to energise the air solenoid) on boot-up and subsequently, provided there is no air failure. They will be set high on this transistor output signal active low controlled by the “engage command”.

Brakes

During the commissioning process it is possible to invert the output from the brake connections from an active low signal to an active high.

General-purpose output

This is an open collector pulled down to the 0 V (24 V return) line via an NPN transistor when activated. It is suitable for driving devices in the range 5 V to 24 V with a maximum output current of 200 mA. If the output is not required, then it should be left open circuit. The output is protected for excess voltage and over-current within the controller.

Switched inputs

Two uncommitted inputs are provided. Each input is activated by being pulled down to the 0 V (24 V return line). The inputs are not opto-isolated and are pulled up to 24 V via a 10 kohm resistor. These inputs can accept signal levels in the range of +5 V to +48 V, and need to be pulled below 1 V to signify a change in state.

De-clutch

This input on pin 20 should normally be pulled down to the 24 V return line, to signal to the controller that the CMM's drives are mechanically connected to the moving elements of the machine, i.e. in their normal condition. The input should be open circuit, or held high, when a CMM has been temporarily ‘de-clutched' from its drive motors to allow manual positioning. The servo system will not drive the motors in this condition and will resume control at the machine‘s position when the signal again goes low.

Low air pressure

The low air pressure signal should be connected to a suitable air pressure switch. This input is monitored by the controller and when activated will remove power from the motors by causing a system fatal fault. During the commissioning process it is possible to invert this signal from an active low signal to an active high. If this capability is not required for integration to the system, then it should be connected to the 0 V (24 V return line).

Crash

The crash signal is used to inform the UCC T3 of a collision of the mechanical structure of the machine. Typically this is a sensor that is fitted to the end of the CMM quill and if activated will remove power from the motors by causing a system fatal fault.

During the commissioning process it is possible to invert this signal from an active low signal to an active high. If this capability is not required for integration to the system, then it should be connected to the 0 V (24 V return line).

Limit switches

The UCC T3 controller supports both inner and outer limit switches for all directions of machine axes. During the commissioning process it is possible to invert this signal from an active low signal to an active high. If this capability is not required for integration to the system, then it should be connected to the 0 V (24 V return line).

Inner limit switches

If an inner limit is activated, the UCC T3 system will perform a maximum movement deceleration in all axes to a stop and then perform a controlled axis back-off in the opposite direction as if a trigger event occurred.

Outer limit switches

If an outer limit is activated the UCC T3 system will immediately disengage all servo power to the machine drives. Recovery of this error is only possible by removing the outer limit switch activation, i.e. by moving the machine off the switch.

0 V (24 V return)

This is the 0 V reference for all the I / O signals.