Siemens SINUMERIK 840D sl Series Diagnostics Manual page 745

08/2005
Cause: The amplitude (C^2 + D^2) of track C or D is not within the tolerance bandwidth.
The nominal signal must be in the range 375 mV to 600 mV (500 mV -25 % / +20 %).
On the other hand, the response thresholds are < 230 mV and > 750 mV (frequency
characteristic).
This fault also occurs if the A/D converter is overcontrolled.
If the amplitude is not within the tolerance bandwidth, then it cannot be used to initialize the
start position.
Alarm value (r2124, decimal):
Low word: Signal level, track C (16 bits with sign).
High word: Signal level, track D (16 bits with sign).
A signal level of 500 mV corresponds to the numerical value 5333 hex = 21299 dec.
Remedy: - check that the encoder cables are routed in compliance with EMC.
- check the plug connections.
- replace the encoder or encoder cable.
- check the encoder module (e.g. contacts).
- check the Hall sensor box
231415 <location>Encoder 1: Amplitude alarm, track A or B (A^2 + B^2)
Reaction: NONE
Acknowledge: NONE
Cause: The amplitude (A^2 + B^2) of track A or B is not within the tolerance bandwidth.
SMC20:
The nominal signal level is at 500 mV (500 mV -25 % / +20 %). The response threshold is
< 300 mV.
SMC10:
The nominal signal level is at 2900 mV (2.0 Vrms). The response threshold is < 1414 mV
(1.0 Vrms).
Alarm value (r2124, decimal):
Low word:
Amplitude square root(A*A + B*B).
SMC20:
A signal level of 500 mV peak value corresponds to the numerical value 299A hex = 10650
dec.
SMC10:
A signal level of 2900 mV peak value corresponds to the numerical value 3333 hex =
13107 dec.
High word:
Angle 0 to 65535 corresponds to 0 to 360 degrees of the fine position. Zero degrees is at
the negative zero crossover of track B.
Remedy: - check the speed range, frequency characteristic (amplitude characteristic) of the
measuring equipment is not sufficient for the speed range.
- check that the encoder cables are routed in compliance with EMC.
- check the plug connections.
- replace the encoder or encoder cable.
- check the encoder module (e.g. contacts).
- dirty code disk
- aged lighting system.
231418 <location>Encoder 1: Speed difference per sampling rated exceeded
Reaction: NONE
Acknowledge: NONE
Cause: The speed difference between two sampling cycles has exceeded half the value of
parameter p0492.
The error is only evaluated for HTL/TTL encoders.
Alarm value (r2124, decimal):
Speed difference per current controller clock cycle in increments.
© Siemens AG, 2005. All rights reserved
SINUMERIK 840D sl/840D/840Di/810D Diagnostics Guide (DA), 08/2005 Edition
Overview of Alarms
2-745