重大利好消息，840dsl v4.7有了解决方案：

31046 ENC_PASSIVE_PARKING A02 -
- Park passive measuring system

Description: The machine data can be used to configure the behavior for the passive measuring
system:
MD = 0:
The passive measuring system is continuously monitored and updated.
MD = 1:
The passive measuring system is automatically parked. It is no longer monitored or
updated. The encoder cable can be disconnected without an alarm being issued.
Notes:
- A measuring system switchover to a parked measuring system takes longer than a
switch to a passive measuring system.
- On account of the duration, an axis standstill is recommended for the switchover.
- It is only with incremental encoders that the position and the state "Measuring
system is referenced" are applied from the previously active measuring system as a
function of MD34210 $MA_ENC_REFP_STATE. In this case, renewed referencing is not
absolutely necessary.
The machine data is inactive if:
- MD30200 $MA_NUM_ENCS is less than 2
- MD30240 $MA_ENC_TYPE=0
- The measuring system is used on the drive side, for example as a motor measuring
system for speed control. Recommendation: Do not change the default value of the
machine data for a motor measuring system.
- MD32950 $MA_POSCTRL_DAMPING>0
- MD32960 $MA_POSCTRL_DUAL_FEEDBACK_TIME>0