Control Techniques Digitax ST Advanced User's Manual page 59

Parameter Keypad and
structure display
Encoder trips
The following table shows trips that can be initiated that are related to the drive encoder feedback and whether they can be enabled and disabled by
Pr 3.40.
Encoders
All
Ab, Fd, Fr, Ab.Servo, Fd.Servo,
Fr.Servo,
SC, SC.Hiper, SC.EnDat, SC.SSI
Ab.Servo, Fd.Servo, Fr.Servo
SC.Hiper, SC.EnDat, SC.SSI
SC.Hiper, SC.EnDat, SC.SSI
EnDat
SSI
SC.Hiper, SC.EnDat, EnDat
SC.Hiper, SC.EnDat, EnDat
SSI, SC.SSI
SC, SC.Hiper, SC.EnDat,
SC.SSI, EnDat, SSI
SC.Hiper, SC.EnDat, EnDat
All
All
SC, SC.Hiper, SC.EnDat, SC.SSI Failure of analog position alignment during encoder initialisation
SC.Hiper
SC.EnDat, EnDat
SC.EnDat, EnDat
SC.Hiper, SC.EnDat, EnDat
SC.EnDat, EnDat
SC.Hiper, SC.EnDat, EnDat
+These trips can be enabled/disabled by Pr 3.40
1. If the terminations are not enabled on the A, B or Z inputs the wire break system will not operate. (Note that as default the Z input terminations
are disabled to disable wire break detection on this input). No wire break detection is provided on the U, V or W commutation signals.
2. Phase error for a servo type encoder is to detect that the incremental pulses have been counted incorrectly. The error is detected if the
incremental position moves by 10° with respect to the position defined by the UVW commutation signals. The trip is initiated if the error is
detected for 10 consecutive samples.
3. Phase error for SinCos encoders with comms is detected by interrogating the encoder every second via comms to compare the incremental
position determined from the sine waves with the incremental position via comms. If the error is greater than 10° for 10 consecutive samples the
trip is initiated. It should be noted that this system should not be used where 180 x Pr 5.11 (or Pr 21.11 for motor map 2) / Pr 3.34 is greater than
10° or else incorrect EnC3 trips will occur.
4. Incorrect encoder phasing is detected if the motor reaches half of the speed defined by SPEED_FREQ_MAX and the phasing error is larger
enough for the motor to accelerate uncontrollably. It can be disabled by setting Pr 3.08 to any value greater than zero.
5. This trip can also be caused when data is transferred between the encoder and a Solutions Module, such as an SM-Applications module, and an
error other than those covered by EnC5 or EnC6 occurs.
Digitax ST Advanced User Guide
Issue Number: 1
Parameter
Parameter x.00
description format
Power supply short circuit
+Hardware wire-break detect on A, B and Z inputs
Software wire break detection on sine wave signals
There is no wire break detection on the U, V and W commutation inputs
(2)
+Phase error
+Sine/cosine phase error
(5)
Comms failure (timeout)
Comms failure (timeout) or transfer time too long
Comms transfer time is too long
Checksum/CRC error or SSI not ready at start of position transfer (i.e. data
input not one)
The encoder has indicated an error
+Power supply failure
Initialisation has failed due to a comms error.
Auto-configuration has been requested by changing Pr 3.41, but an
initialisation has not occurred to perform auto-configuration.
Speed feedback selected from an option slot that does not have a position
feedback category Solutions Module installed
Incorrect encoder phasing
The encoder type could not be identified during auto-configuration
The number of encoder turns read from the encoder during auto-
configuration is not a power of 2
The number of bits defining the encoder position within a turn read from the
encoder during auto-configuration is too large.
The number of periods per revolution is either less than 1 or greater than
50000 when read or calculated from the encoder data during auto-
configuration.
The number of comms bits per period are larger than 255.
This is a rotary encoder (Pr 3.39=1 or 2) and the lines per revolution read
from this encoder are not a power of two.
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Advanced parameter Serial comms
descriptions protocol
Reason for error
(1)
(3)
(4)
Electronic
Performance
nameplate
Drive trip
EnC1
EnC2
EnC3
EnC4
EnC5
EnC6
EnC7
EnC8
EnC9
EnC10
Enc11
Enc12
Enc13
Enc14
Enc15
Enc 16
Enc 17
Menu 3
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