The Laser Safety Interlock - THORLABS MX10C Series User Manual

MX10C, MX40C Series of Optical Transmitters Chapter 6: Control and PC Connections

6.2 The Laser Safety Interlock

The instrument is equipped with a remote interlock connector located on the rear panel. In order to enable the laser source, a
short circuit must be applied across the terminals of the Remote Interlock connector. In practice this connection is made
available to allow the user to connect a remote actuated switch to the connector. The switch (which must be normally open)
has to be closed in order for the laser to be enabled. If the switch changes to an open state, the laser source will automatically
shut down. If the switch returns to a closed condition the laser source must be turned on again in the touchscreen GUI.
All units shipped from Thorlabs are configured with a shorting device installed in the Interlock connector. If you are not going to
use this feature, then leave the shorting device installed. The unit will operate normally as described in the procedures above.
If you wish to make use of the Interlock feature you will need to acquire the appropriate 2.5 mm plug, wire it to the remote
interlock switch, and then plug it in to the back-panel interlock jack in place of the shorting plug. This type of plug is readily
available at most electronics stores. The electrical specifications for the interlock input are shown in the following table.
Specification Value
5 VDC Max
Type of Mating
2.5 mm Mono Phone Jack
Ground
Connector
Open Circuit Voltage <5 VDC (On Barrel of Plug)
Short Circuit Current 7 mA (Typical)
Connector Polarity Tip is Ground, Barrel is at 5 VDC Max
Must be normally open dry contacts
Interlock Switch
Apply no external voltages to the
Requirements
interlock input
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