MTS FlexTest Models 200 - Manual (Page 24)

MTS FlexTest® Models 40/60/100/200 Controller Hardware
Safety Circuits
Safety Information 24
Hardware Interlocks
A Series 494 controller running Series 793 Control Software can have up to eight
separate hardware interlock chains. Each test station configuration that you open
must be assigned to a unique hardware interlock chain. This allows one controller
to run up to eight test stations, each with its own hardware interlock chain.
Note Some test configurations may only use one station that is assigned to a
single hardware interlock chain.
The controller can generate two type of hardware interlocks, global interlocks,
and station interlocks:
Global interlocks
Global interlocks detect controller chassis conditions (such as watchdog timers
and undervoltage conditions) that can affect any station running on the controller.
A global interlock forces all eight hardware interlock chains to an active state.
Station interlocks
Station interlocks are associated with a specific test station and will force the
hardware interlock chain assigned to that station to an active interlock state.
Series 494 controllers include interlock output contacts (NO/NC) that are
intended to provide hardware interlock status to external systems.
Note If necessary for critical applications, you can use an external I/O
monitoring device to monitor both NC and NO contacts to detect state
changes and verify relay integrity.