Siemens SINUMERIK 840D sl Function Manual page 1572

Z1: NC/PLC interface signals
19.1 Various interface signals and functions (A2)
DB31, ...
DBX1.5 - DBX1.6
Position measuring system 1 (PMS1) / Position measuring system 2 (PMS2)
Application exam‐
1. Switching over from position measuring system 1 to positioning measuring system 2 (and vice
ple(s)
2. Machine axis is parked:
3. Switch off position measuring system:
4. Reference point approach:
Special cases, If the "parking" state is active, the following interface signal is ignored at NC start for this axis:
errors, .... DB31, ... DBX60.4 / 5 (referenced/synchronized 1 / 2).
Corresponding to ... DB31, ... DBX60.4/.5 (referenced/synchronized 1/2)
DB31, ... DBX61.6 (speed controller active)
DB31, ... DBX2.1 (controller enable)
MD36500 $MA_ENC_CHANGE_TOL (max. tolerance on actual position value switchover)
MD30200 $MA_NUM_ENCS (number of encoders)
Additional references Function Manual, Basic Functions; Velocities, Setpoint / Actual Value Systems, Closed-Loop Control
(G2)
1572
versa).
If the axis was referenced in both position measuring systems and the limit frequency of the used
measured value encoder has not been exceeded in the meantime, i.e.
DB31, ... DBX60.4 and 60.5 == 1 (referenced/synchronized 1 and 2) , a new reference point
approach is not required after the switchover.
On switchover, the current difference between position measuring system 1 and 2 is traversed
immediately.
A tolerance band in which the deviation between the two actual values may lie at the switchover
can be specified in the following machine data:
MD36500 $MA_ENC_CHANGE_TOL (maximum tolerance for actual position value switchover)
If the actual value difference is greater than the tolerance, switchover is not performed and alarm
25100 "Measuring system switchover not possible" is displayed.
The position measuring system monitoring is switched off when the measured value encoder is
removed.
When the position measuring system 1 or 2 is switched off, the associated interface signal is reset:
DB31, ... DBX60.4/5 (referenced/synchronized 1/2)
Reference point approach of the axis is executed with the selected position measuring system.
Every position measuring system must be referenced separately.
Function Manual, 01/2015, 6FC5397-0BP40-5BA2
Basic Functions