MTS Material Test Systems - Manual (Page 24)

3.4.0 Interlocks
The test controller incorporates interlock circuitry that can automatically stop a test when a system problem,
specimen failure, or an operator error could result in unwanted or unexpected actuator movement. The test
controller interlock circuitry will cause one of two interlocks to occur in response to specific conditions
encountered during testing. These interlocks are:
• Hydraulic Interlock – stops the program and removes hydraulic pressure from the system.
• Program Interlock – stops the current test program when certain test parameters are not met or are
exceeded.
Because specimen installation procedures and testing situations can be adversely affected by the sudden
loss of actuator pressure that accompanies a hydraulic interlock, the operator might choose to enable or
disable the interlock detectors during system setup. Disabling the interlock detectors allow the operator to
prevent a hydraulic shutdown if an interlock condition occurs. the following table lists the possible types of
interlock conditions for the test controller.
Table 4: Interlocks
Type of Interlock Cause Condition
Hydraulic Emergency Stop or E-Stop button pressed Emergency Stop
Program Open circuit at the Prog Intlk rear panel connector Program Aux
Hydraulic Fault in the performance of hydraulic components Hydraulic event
Hydraulic Fault in the performance of mechanical components Mechanical event
Hydraulic or Program Completion of a preset number of cycles in the current
test program End-of Count
Hydraulic with indicator
option
1
Selected signal fails to reach a preset minimum or
maximum level Underpeak
Hydraulic with indicator
option
2
When the control channel's DC error signal exceeds
a preset maximum level Error
Hydraulic with indicator
option
3
Transducer feedback signal exceeds a preset
minimum or maximum level Upper LimitLower Limit
1 These interlocks can be set to indicate only. For further information on configuring these interlocks, refer to
the test controller documentation.
2 These interlocks can be set to indicate only. For further information on configuring these interlocks, refer to
the test controller documentation.
3 These interlocks can be set to indicate only. For further information on configuring these interlocks, refer to
the test controller documentation.
24 MTS Material Test System Operation
3.0 Introduction