Parker IPA Series, Hardware Installation Manual

Page: 82 / 128

TORQUE ENABLE SAFETY CIRCUITRY
82 IPA Hardware Installation Guide
Typical Operation
In typical operation, there can be a small time difference between changes of state on TRQ_EN1 and TRQ_EN2,
due to different delays in the operation of two sets of relay contacts.
1 3
<1.6s
1
TRQ_EN1
TRQ_EN2
3
<1.6s
2
States:
1. Both inputs are low. Hardware prevents the drive from starting. This is the torque disabled state
of the drive.
2. Both inputs are high. Drive is able to run under software control.
3. One input is high and the other input is low. Drive is tripped and cannot start due to torque
disabled state. Normal operation allows this state to persist for up to 1.6 seconds which is the
minimum fault detection time required to generate a fault (3.0 seconds is the maximum). These
tolerable time differences are normally caused by switches or relays; they should be kept as short
as possible.
Fault Operation
A fault is always detected when TRQ_EN1 and TRQ_EN2 are in opposite states for more than 3.0 seconds.
1 3
1.6s
TRQ_EN1
TRQ_EN2
4
TRQ_LATCH
3.0s