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SPA3 installation guide
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Brakes
These outputs (pins 3, 4 and 5) are used to disengage the CMM axis brakes if fitted. These outputs become active as soon as the CMM
servos are engaged. 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
It is an open collector pulled down to the 0 V 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. 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 be pulled down to the 0 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 the
CMM has been temporarily "de-clutched" from the 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 current position when the signal 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.
Crash
The crash signal is used to inform the SPA3 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.
Limit switches
The SPA3 controller supports both inner and outer limit switches for each 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 .
Inner limit switches
If an inner limit is activated the SPA3 system will perform a maximum movement de-acceleration in all axes to a stop and then
perform a controlled axis back-off in the opposite direction, as if a trigger event occurred.
Issued 01 2018
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