Siemens SINUMERIK 840D Function Manual page 680

H1: Manual traversing
17.10 Position travel in JOG
Retraction in the opposite direction
The behavior when retracting from the position in the opposite direction depends on the setting
of bit 2 in the machine data:
MD10735 $MN_JOG_MODE_MASK (settings for the JOG mode)
Retraction in the opposite direction is possible only if the bit is set.
If the bit is not set, retraction in the opposite direction is blocked, and the following channel
status message is output if an attempt is made with the traverse keys or with the handwheel to
exit the approached position in the opposite direction:
"JOG: Direction blocked <axis>"
Special case: axis is already at position
The axis cannot be traversed if the axis is already at the position to be approached when
starting the JOG motion. This is displayed through the following channel status message:
"JOG: position reached <axis>"
To retract, the function "Position travel in JOG" must be deactivated.
Special features of incremental travel
If, during incremental travel, the position is reached before the increment is completed, then the
increment is considered to have been completed fully. This is the case even when only whole
increments are traveled.
MD11346 $MN_HANDWH_TRUE_DISTANCE = 2 or 3
Special features of modulo rotary axes
Modulo rotary axes can approach the position in both directions. The shortest path (DC) is not
observed during the travel.
Features of spindles
A spindle changes to the positioning mode on actuating the "Position travel in JOG" function.
The closed loop position control is active and the axis can be traversed to the position.
If no zero mark is detected the alarm message in the axis operation is output:
Alarm 17810 "Channel %1 Axis %2 not referenced"
As a spindle must also be a modulo rotary axis at all times, the same conditions apply for
direction observation as for modulo rotary axes (refer to the paragraph "Features of modulo
rotary axes")
See also
Parameter setting (Page 681)
680
Axes and spindles
Function Manual, 06/2019, A5E47437747B AA