MTS Model FlexTest SE - Manual (Page 22)

Models FlexTest® IIm/GT/SE Controller Hardware
Hydraulic Control
Introduction 22
Cooling The chassis is cooled with a fan. An overtemperature sensor is part of the
standard power supply assembly. If the internal chassis temperature exceeds
50ºC, this sensor will light an amber indicator located on the rear of the power
supply module.
Hydraulic Control
Hydraulic control is handled with two transition modules:
• The Model 493.73 HPU Transition module has a connection to control a
hydraulic power unit. It includes connections for an emergency stop button
and digital I/O for system communications.
• Typically, up to four Model 493.74 HSM Transition Modules can be used to
support up to eight HSM stations. Each HSM module includes connections
to support two stations. Each station supports an HSM, a load unit, run/stop
outputs, auxiliary outputs, and interlock controlled outputs.
Interlocks
Two types of interlocks are supported, the system wide interlock and station
interlocks. The system wide interlock shuts down the hydraulic power unit and
all stations, and the station interlock shuts down a single station leaving other
stations running. The emergency stop function on the Model 493.74 HSM
transition board contains two separate circuits, the system wide interlock (HPU)
and the station interlock (HSM).
System wide interlock
The emergency stop circuit consists of a loop that only runs through the rear
panel transition boards of the chassis. Any board that generates an interlock by
breaking this system wide loop causes the hydraulic power unit to be shut down.
This will also cause all of the stations to shut down.
Note The emergency stop circuit meets the requirements of the Machinery
Safety Directive (EN 60204-1, 1992, section 9.2.5.4). This means the
emergency stop circuit is hard-wired with electromechanical
components.
Station interlocks Each station represents all of the components associated with an interlock chain.
All of the modules plugged into the chassis can be assigned to stations. If one of
the stations generates an interlock, all of the components assigned to the station
are shut down.
Standard configurations support up to four independent stations.