Siemens SINUMERIK 840C - Manual (Page 746)

10 Axis and Spindle Installation 09.95
10.5.3 Positioning mode, M19, M19 through several revolutions
Data required
This section describes the data that is of special significance to the positioning mode. A
detailed description of the machine data and setting data will be found in the Section "NC
Machine Data (NC MD)/NC Setting Data (NC SD)".
• Position
An absolute position is given in response to a request from the NC or PLC. The position is
specified by S value, machine data or setting data. The values must be within the range 0
to 359.99° and the entry must be to an accuracy of 0.01°.
• Distance traversed
An incremental path is given in response to a request from the command channel. This
path is specified in the user data of the command channel and can be more than one
revolution. The size is only limited by the numerical format. The value must again be
accurate to 0.01° and its mathematical sign determines the direction of rotation for
positioning.
• Override factor
The speed during positioning can be influenced by the spindle override factor.
• Other data
Positioning is effected with interpolation guiding and under position control. The following
data is needed:
–
Maximum permitted speed during positioning
– Maximum permitted acceleration
– Gain factor
– Position window
This information is transferred to the user data on request from the command channel.
When there is a request from the NC or PLC, the corresponding machine data of the
active gear ratio is used, which is:
– MD 427* to 434* ”Creep speed for M19” as max. speed during positioning
– MD 478* to 485* ”Acceleration time constant with position control” for
limiting the acceleration rate during acceleration and
deceleration
– MD 435* to 442* ”Gain factor” for the position controller
– MD 443* ”Position tolerance” for establishing the position window
(regardless of the active gear ratio)
If the gain factor is required to be changed in the positioning mode, the following will also
be needed:
– MD 469* ”Factor for gain changing”
– Output of signal "Spindle position reached" (DB31 DLK bit 4) to the PLC if the current
spindle position has not reached the tolerance range set in MD 4430.
– M19 is completed when the PLC outputs signal "Acknowledge M19" (DB31 DRK + 2
bit 2), or with M3, M4. In this case the position control loop is opened but the spindle
controller enable relay does not drop out (spindle can drift out of position).
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SINUMERIK 840C (IA)