Parameter and variable descriptions 6-35 – Rockwell Automation 1557 MEDIUM VOLTAGE AC DRIVE User Manual
Page 91
PARAMETER AND VARIABLE DESCRIPTIONS
6-35
1557-UM050F-EN-P – June 2013
Tachometer Pulses Per Revolution [Tach pulse/rev]
Linear number:
234
Minimum value:
120
Maximum value:
4096
Default value:
360
This parameter specifies the number of pulses produced by the tachometer in one revolution. This parameter
is not used for absolute encoders.
Tachometer Loss Trip [Tach loss trip]
Linear number:
235
Minimum value:
0.0 Hz
Maximum value:
10.0 Hz
Default value:
2.0 Hz
This parameter specifies the amount by which the speed feedback from the tachometer and the speed
feedback derived from stator frequency must differ before a tachometer loss fault is indicated.
Tachometer Loss Delay [Tach loss delay]
Linear number:
236
Minimum value:
0.00 sec
Maximum value:
1.00 sec
Default value:
0.10 sec
This parameter specifies the time that the tachometer error must be greater than the trip level before a
tachometer loss fault is indicated.
Tachometer Select [Tach select]
Linear number:
237
Minimum value:
0
Maximum value:
3
Default value:
0
This parameter specifies which of the four tachometer inputs available on the Tachometer Feedback Board is
to be used by the drive. It is not used for synchronous motors with absolute encoders.
Encoder Offset [Encoder offset]
Linear number:
238
Minimum value:
0 deg
Maximum value:
359 deg
Default value:
0 deg
This parameter specifies the value of the offset between the rotor d-axis of the synchronous machine and the zero
of the absolute position encoder. It can be set manually or by autotuning. This parameter is not used for induction
motors with incremental encoders.
Warning:
Parameter “Speed Feedback Select” should not be set to 1 until the encoder offset has been correctly
set.
This parameter was added in Rev 5.20 and is not present in 4.xx.