6 NC Machine Data (NC MD), NC Setting Data (NC SD) 07.97
6.6.2 Spindle-specific MD bits (spindle bits)
76543210
Bit No.
NC MD
521*
Spindle
available
No spindle
zero speed
with M03
and Reset
New S
value after
gear
acknow.
Switch off
C axis
mode on
RESET (as
from SW 2)
No
measuring
circuit
monitoring
Ramp-up
as C axis
(as from
SW 4)
Setpoint
sign change
Automatic
drift
compen-
sation on
M19 (as
from SW 2)
Default value
MD 840C (T) 840C (M)
5210 1000 0000 0000 0000
5211 - 5215 0000 0000 0000 0000
Bit 7 A SINUMERIK 840C system can include up to 6 spindles.
Active: POWER ON
Bit 6 Instead of being decelerated to zero speed on a key-initiated reset, mode
change or M2 / M30, the spindle continues to rotate at the spindle speed last
programmed (spindle override active). In this case, the spindle can be
decelerated with the interface signal "Spindle RESET" (DB 31 DRk + 1, bit 5).
EMERGENCY STOP (alarm 2000) and all alarms that result in removal of the
"Mode group ready" interface signal decelerate the spindle to zero speed in all
cases (mode group-specific).
The "Spindle RESET" signal is effective only when the channel to which the
spindle is currently allocated (DB 31 DLK + 1, bits 0 to 4) is in the RESET
state.
This bit has no effect on the M19 function (spindle positioning); only NC MD
520*, bit 6, is relevant.
Active: In next block
Bit 5 Up to SW 4
A newly programmed spindle speed, which requires a gear change (automatic
gear selection in the NC), is not accepted until the gear change has been
acknowledged over the interface (DB31, DRk, bit 7), thus preventing an
unintentional speed increase in the old gear prior to a gear change.
Active: NC STOP
Bit 5 As from SW 5
Bit 5=0 The new speed setpoint is output immediately on a gear stage change.
Bit 5=1 Spindle speed not accepted until acknowledged by PLC.
The new speed setpoint is not output until interface signal ”Switch over gear”
has been acknowledged by the PLC user program.
Bit 4 Whether C axis mode is maintained on RESET depends on how bit 4 is set.
Bit 4=0 C axis mode is maintained
Bit 4=1 C axis mode is switched off on RESET
6–126 © Siemens AG 1992 All Rights Reserved 6FC5197- AA50
SINUMERIK 840C (IA)