Siemens SINUMERIK 840D sl Function Manual page 99

Note
Rotary absolute encoders
If the plausibility check is to be used for a rotary absolute encoder, the SINAMICS parameter
p0979 must be taken into account when setting the modulo range (MD34220
$MA_ENC_ABS_TURNS_MODULO).
Note
Upgrading the NCK software
If the plausibility check is activated in absolute encoders (MD36310 > 0), the existing MD36310
settings must be checked and, if necessary, increased during an upgrade of the NCK software.
Zero mark diagnostics
With absolute encoders, the permissible deviation must be determined for the plausibility check
during commissioning. This can be performed via the machine data:
MD36312 $MA_ENC_ABS_ZEROMON_WARNING (zero-mark monitoring warning threshold)
Value
0
> 0
Procedure when commissioning the system:
1. Deactivate zero-mark monitoring:
MD36310 $MA_ENC_ZERO_MONITORING = 0
2. Activate zero-mark diagnostics:
MD36312 $MA_ENC_ABS_ZEROMON_WARNING = 1
3. Move axis and monitor system variable $VA_ENC_ZERO_MON_ERR_CNT (number of
detected limit value violations).
4. If $VA_ENC_ZERO_MON_ERR_CNT ≠ 0:
Increase MD36312 value and repeat step 3.
5. If $VA_ENC_ZERO_MON_ERR_CNT = 0 (over a longer period of time!):
The correct value for MD36310 is located! Apply the value from MD36312 to MD36310 and
then set MD36312 to "0".
Note
Depending on the rigidity of the machine (minimal load masses / moments of inertia are
optimum) and the controller settings, the control play "oscillates" with varying degrees of
intensity. Account must be taken of this by entering machine-specific limit values in MD36310.
Basic Functions
Function Manual, 01/2015, 6FC5397-0BP40-5BA2
Meaning
No zero mark diagnostics
Permissible deviation in 1/2 coarse increments between the absolute and the incremental
encoder track
A3: Axis Monitoring, Protection Zones
3.2 Axis monitoring functions
99