ABB ACSM1 Manual page 232

232
62.30 PROBE TRIG FILT
To avoid false latch events due to signal disturbances, latchings are verified on the basis of a low-pass
filtered signal. The signal is filtered using the time constant (τ) defined by this parameter. In effect, the
value of this parameter determines how long the probe signal must stay in its new state to be
accepted as a latching.
After the state of the selected latch input changes, the state of the filtered signal is checked at 2τ to
verify the change. If the signal has remained in its new state, the latching is accepted and new
latching events prevented until the drive has read the latched position from the FEN-xx adapter. If the
signal has not remained in its new state, the latching is discarded and a new one allowed immediately.
The diagram below illustrates an ideal probe signal and a filtered signal. In this instance, the rising
edge of the digital input is used as the triggering command.
(0) 125 us
(1) 250 us
(2) 500 us
(3) 1000 us
62.31 CYCLIC COR STYLE
Sets the cyclic correction style.
(0) Once
(1) Continuous
Parameters and firmware blocks
FW block: HOMING (see above)
Ideal probe signal
Filtered probe signal
Latch verification
Latch detection
125 µs.
250 µs.
500 µs.
1000 µs.
FW block: None
Selection Once requires that the previous correction is done before
the next measurement for the correction is allowed.
Selection Continuous allows a new correction even though the
previous correction is not ready