Siemens SINUMERIK 840D sl Series Diagnostics Manual page 755

08/2005
Cause: SMC20:
The nominal signal level of the encoder must lie 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).
SMC10:
The nominal signal level is at 2900 mV (2.0 Vrms). The response thresholds are at < 1070
mV and > 3535 mV.
Fault value (r0949, decimal):
Low word:
Signal level, track A (16 bits with sign).
High word:
Signal level, track B (16 bits with sign).
SMC20:
A signal level of 500 mV peak value corresponds to the numerical value 5333 hex = 21299
dec.
SMC10:
A signal level of 2900 mV peak value corresponds to the numerical value 6666 hex =
26214 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).
232116 <location>Encoder 2: Amplitude error, monitoring track A + B
Reaction: A_INFEED: NONE
SERVO: ENCODER (DCBRAKE, NONE)
Acknowledge: IMMEDIATELY
Cause: The amplitude of the rectified encoder signals A and B is not within the tolerance bandwidth
(hardware monitoring).
The nominal signal level of the encoder must lie in the range 375 mV to 600 mV (500 mV
-25 % / +20 %).
On the other hand, the hardware response thresholds are at < 176 mV and > 1.35 V.
Fault value (r0949, decimal):
Low word: Signal level, track A (16 bits with sign).
High word: Signal level, track B (16 bits with sign).
A signal level of 500 mV corresponds to the numerical value 5333 hex = 21299 dec.
These analog values are not measured at the same time with the hardware fault output.
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).
232117 <location>Encoder 2: Inversion error, signals A and B
Reaction: A_INFEED: NONE
SERVO: ENCODER (DCBRAKE, NONE)
Acknowledge: IMMEDIATELY
Cause: For a square-wave signal encoder (TTL. bipolar. double ended) the A* and B* signals are
not inverted with respect to signals A and B.
Remedy: Check the setting of p0405: p0405.2 = 1 is only possible if the encoder is connected at
X520.
Check the encoder/cable: Does the encoder supply TTL signals and the associated
inverted signals?
© Siemens AG, 2005. All rights reserved
SINUMERIK 840D sl/840D/840Di/810D Diagnostics Guide (DA), 08/2005 Edition
Overview of Alarms
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