Low air pressure
The low air pressure signal should be pulled 'low' through 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' signal. If this capability is not required the signal should be connected to 0 V or inverted
during commissioning.
NOTE:
It is strongly recommended to monitor supply air pressure if the CMM is using air bearings and / or a pneumatic counter
balance.
Crash
The crash signal is used to inform the SPA3-2 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. If this capability is not required for integration the signal should be
connected to 0 V or inverted during commissioning.
Limit switches
The SPA3-2 controller supports both inner and outer limit switches for each of the machine axes. During the commissioning process it is
possible to invert these signals. If this capability is not required for integration to the system then they should be connected to 0 V or inverted
during commissioning.
Inner limit switches
If an inner limit is activated the UCC 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.
Outer limit switches
If an outer limit is activated the UCC system will immediately disengage all servo power to the machine drives and apply the machine brakes.
Recovery of this error is only possible by removing the outer limit switch activation (i.e. by moving the machine off of the switch).
0 V
This is the 0 V reference for all of the I/O signals.
NOTE:
All input signals can be inverted from active low to active high during the commissioning process, however care should be
taken as this may prevent the input being detected in the event of input disconnection or cable break. It is therefore NOT
recommended to invert inputs where possible.
SPA3-2 installation guide
www.renishaw.com
Issued 08 2020
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