Siemens SINUMERIK 840D sl Function Manual page 91

Encoder
type
0
1
2
3
4
5
Activation/Deactivation
The function is activated/deactivated with machine data:
MD36310 $MA_ENC_ZERO_MONITORING (Zero-mark monitoring)
MD36310
0
> 0
100
2.1.5.3 Zero-mark monitoring for incremental encoders
Function
Incremental encoders with one or more zero marks use the zero-mark signals to check the
plausibility of the actual values.
Monitoring starts with the first zero-mark signal once the encoder has been switched on
(fault counter = 0). The function checks whether the number of incremental signals is
plausible after each zero mark (if equidistant zero marks) or after every second zero mark (if
distance-coded zero marks). This is the case, for example, if the number of incremental
signals from straight-line axis motions matches the value required for the distance between
two relevant zero marks. In the event of a non-plausible deviation, the fault counter
increases by 1. The zero-mark monitoring is tripped (alarm) if several non-plausible
deviations occur in direct sequence and the fault counter exceeds the configured permissible
number of deviations:
MD36310 $MA_ENC_ZERO_MONITORING (Zero-mark monitoring)
If a plausible value is recorded before this threshold is reached, the fault counter is reset to
0. This ensures that the non-plausible deviations only trigger an alarm if they occur in direct
sequence and in a non-tolerable number.
Basic logic functions: Axis monitoring, protection zones (A3)
Function Manual, 11/2006, 6FC5397-0BP10-2BA0
Meaning
Simulation
Raw signal generators (voltage, current, EXE etc.) → High resolution
Rectangular signal encoder (standard, no. of PPRs quadrupled)
Reserved
Absolute encoder with EnDat interface
Absolute encoder with SSI interface
Meaning
No zero-mark monitoring.
Zero-mark monitoring active.
No zero-mark monitoring and all encoder alarms concealed.
Detailed description
2.1 Axis monitoring
25