7
Safety Interlock and Remote Interlock
The system interlock line is a hardware safety line that controls the signal output of all laser
sources within the MAP system. The interlock line connects the MAP chassis to each laser in
the system. If the interlock circuit is broken, interlock is considered activated and all laser
sources are immediately disabled removing all light at the output connectors. Upon deactivation
of the interlock line, all laser sources are enabled after a six-second delay (assuming they have
been previously enabled). Operation and control of this line is hardware-based, therefore it is
not susceptible to software failure. User of the system interlock line is performed in two ways:
Safety Interlock key found on the master local user interface must be inserted in controller
cassette (green color upward) for the interlock to be deactivated. An operator may remove the
key when leaving the MAP unsupervised to ensure that untrained or unprepared users do not
unintentionally expose themselves to dangerous levels of optical energy.
Remote Interlock is normally a closed circuit on the master remote, the interface is available to
be integrated into a user’s safety system. A typical application would be an interruption circuit
tied to a door switch that would activate the system interlock when a door is opened. Therefore
unprepared persons entering a room where a MAP system is located will not be exposed to
hazardous levels of optical energy.
NOTE: If a slave chassis is powered while no master chassis is present on the inter-chassis
bus, the interlock line will be activated.
The interlock line will deactivate all laser sources regardless of their settings, but other factors
such as current setting and laser activation have to be considered when enabling a source
output. The following truth table shows the relationship of the system interlock line, and the
source activation circuit.
Table 3: Laser Source Signal Output Truth Table
Laser State Interlock Signal Out
Inactive X No
X Active No
Active Inactive Yes
Caution
• Use of controls or adjustments or performance of procedures other than
those specified herein may result in hazardous radiation exposure.
• Use of any cassettes with no optical energy source in conjunction with
sources must be conducted with care and recognition of the safety required
according to the classification of the source.
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