Siemens SINUMERIK 840D sl Function Manual page 240

H1: Manual and handwheel travel
4.15 Start-up: Handwheels
Filter time
Since the handwheel pulses on the Ethernet bus are not transferred deterministically, filtering
(smoothing) of the handwheel pulse transfer process may be necessary for highly dynamic
drives. The parameter for the filter time is assigned using the following machine data:
● MD11354 $MN_HANDWHEEL_FILTER_TIME[< x - 1 >] = <filter time>
where x = 1, 2, 3, etc. (handwheel number in the NC) and filter time = 0.0 to 2.0 s
The filter time specifies the time it takes for the handwheel pulses transferred to the control to
be sent on to the interpolator for traversing purposes. With a filter time of 0.0 s, the handwheel
pulses are sent on to the interpolator within a single interpolation cycle. This can result in the
relevant axis being traversed jerkily.
The recommended filter time is 0.2 to 0.5 s.
Stationary state detection
A stationary state is detected by the Ethernet modules to which the handwheel is connected.
If a handwheel does not transfer any handwheel pulses for a defined period of time, the module
detects this to be a stationary state and transfers it to the NC/PLC interface:
NC/PLC interface signal
DB10, DBX245.0
DB10, DBX245.1
DB10, DBX245.2
By evaluating the signal, it is possible to reduce the overtravel of an axis traversed via the
handwheel, due to the handwheel pulses that have been collected in the control but not yet
transferred to the interpolator for traversing purposes. To do this, deletion of the distance-to-
go must be triggered for the relevant axis or in the channel when a stationary state is detected:
● DB31,... DBX2.2 = 1 (axial deletion of distance-to-go)
● DB21,... DBX6.2 = 1 (channel-spec. deletion of distance-to-go)
240
Value Description
0 Handwheel 1 is operated
1 Handwheel 1 is stationary
0 Handwheel 2 is operated
1 Handwheel 2 is stationary
0 Handwheel 3 is operated
1 Handwheel 3 is stationary
Function Manual, 10/2015, 6FC5397-1BP40-5BA3
Extended Functions