Siemens SINUMERIK 840C - Manual (Page 743)

09.95 10 Axis and Spindle Installation
10.5.1 Open-loop control mode
In view of the fact that not all spindle drives are equipped with ramp-function generators, a
ramp-function generator was integrated in the control (unit 1 ms). The following enable signals
are required for spindle setpoint output:
DB 31 Spindle-specific signals
• DL
K
+
1
bit 6= 1 "Servo enable"
• DL
K
+
1
bit 5= 0 "Default setpoint is 0"
• DW
K
+
3
all bits= 0 "Spindle disable"
• Setting data "Spindle speed limitation"
Note:
See also functional description ”Parameter set switchover” in Section 12.
Data required
This section describes the data that is of particular significance to the open-loop control mode.
• Limiting the speed
Parameters for maximum and minimum speed limits can be assigned for each gear ratio.
Parameter assignment is effected through the machine data:
–
MD 403* to 410* ”Max. speed” per gear ratio
– MD 411* to 418* ”Min. speed” per gear ratio
If a gear stage is not used, the value zero must be entered for the maximum speed of this
gear stage and not the value in the standard machine data.
Regardless of which gear ratio is active, the speed is limited by:
–
MD 451* ”Max. chuck speed”
– MD 448* ”Min. motor speed”
– SD 401* ”Programmable spindle speed limit for G96”; programmed with
G92
– SD 403* ”Programmable spindle speed limit”; programmed with G26
• Limiting the acceleration
In order to avoid excessive acceleration when changing speeds, the setpoint is ramped up
or down accordingly by means of a ramp-function generator. The maximum value of
acceleration to be used is assigned by means of an acceleration time constant. A
separate acceleration time constant must be specified for each gear ratio employed:
– MD 419* to 426* ”Acceleration time constant without position control”
© Siemens AG 1992 All Rights Reserved 6FC5197- AA50 10–53
SINUMERIK 840C (IA)