Siemens SINUMERIK 840C Installation Instructions Manual page 838

11.92
Relevance of machine data bits for sign inversion
Setpoint/actual value for spindle + C axis
The following machine data are affected:
MD 564*, bit 1: "Sign inversion setpoint"
MD 564*, bit 2: "Sign inversion actual value"
MD 520*, bit 1: "Sign inversion actual value"
MD 521*, bit 1: "Sign inversion setpoint"
Whether these machine data bits have to be set or not depends on the configuration.
Possible configurations are:
a) Spindle and C axis have the same actual value input:
Only MD 520*, bit 1, must be correctly set. MD 564*, bit 2, is of no significance, even in C
axis operation.
b) Spindle and C axis have different actual value inputs:
The sign must be correctly set for each actual value input. MD 520*, bit 1, and MD 564* bit
2, must be set correctly. The set signs take effect in one or the other of the operating
modes.
Spindle operation: MD 520*, bit1 active.
C axis operation: MD 564*, bit2 active.
c) Spindle and C axis have different setpoint outputs:
The sign must be correctly set for each setpoint input. MD 521*, bit 1, and MD 564*, bit 1,
must be correctly set. The set signs take effect in one or the other of the operating
modes.
Spindle operation: MD 521*, bit1 active.
C axis operation: MD 564*, bit1 active.
d) Spindle and C axis have the same setpoint output:
The sign must be correctly set for each setpoint output. MD 521*, bit 1, and MD 564*,
bit 1, must be correctly set. The set signs take effect in one or the other of the operating
modes.
Spindle operation: MD 521*, bit1 active.
C axis operation: MD 564*, bit1 active.
© Siemens AG 1992 All Rights Reserved
SINUMERIK 840C (IA)
6FC5197- AA50
12 Functional Descriptions
12.7.2 Description of the spindle modes
12–63