12 Functional Descriptions 12.93
12.18.13 Start-up
Setting the interlocks
To complete the start-up procedure, you now need to set or reset the interlock or enable bits
for certain GI functionalities according to the machine manufacturer's data. The following
settings are available:
• NC MD 1456*/496* Default setting of link structure
• NC MD 1844*/525* bit1 Reconfiguration permissible
• NC MD 1844*/525* bit2 Switchover of link factor permissible
• NC MD 1844*/525* bit3 Overwriting of positions permissible
• NC MD 1844* bit4 LINK_ON after power on
12.18.14 Special cases of gearbox interpolation12.18.14.1 Synchronous spindle
If only the "Synchronous spindle" option is set, then several pairs of
synchronous spindles can be configured. The selected gearbox
interpolation type is subject to the following restriction:
Only one leading spindle can be configured for each following spindle.
The synchronous spindle function is especially important for the "on-the-fly transfer" of the
workpiece from the working spindle. During this process, the workpiece is transferred to the
synchronous spindle (following/counter-spindle) while the main (leading) spindle is rotating. In
this case, the synchronous spindle must be synchronized with the main spindle in terms of
speed and, with shaped workpieces, also in terms of position.
The synchronous spindle is programmed by means of the G400, G401, G402 and G403
commands in conformity with the general programming options for gearbox interpolation.
The interface signal INTERLOCK LINK ON can also be applied in this case to influence the
activation and deactivation of the gearbox link from the PLC.
The following special features must be noted with respect to the "Synchronous spindle"
functionality or following spindles:
POWER ON/Ramp-up/Start-up
• The leading and following spindles are always in the spindle mode after POWER ON. LINK
ON cannot be activated after POWER ON in this case (in contrast to axes).
• A pulse encoder must be provided for the leading and following spindles.
• The spindle drift must be compensated.
• The position control loops of the spindles must be set to the same following error for a
setpoint link.
• The leading and following spindles are always operated under position control in
synchronous operation.
• If a simulated spindle is to act as the leading spindle, NC MD 520*.2 (pulse encoder
installed) and the NS SPEED CONTROLLER ENABLE must be set for the spindle (even
when a pulse encoder is not connected).
12–166
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SINUMERIK 840C (IA)