Fagor 8070 BL - Selecting the Loop for an Axis or a Spindle. Open Loop or Closed Loop

Programming manual.
CNC 8070
STATEMENTS AND INSTRUCTIONS
22.
Programming statements
·407·
(REF: 1709)
22.1.12 Selecting the loop for an axis or a spindle. Open loop or closed loop
When working in open loop, the command does not depend on the feedback. When working
in closed loop, the command is generated according to the feedback.
The spindle usually works in open loop when it is in M3 or M4 and in closed loop when it
is in M19. In spindle synchronization, the slave always works in closed loop and the master
can work either in open loop or closed loop depending on the programming parameters of
the #SYNC instruction. However, it is possible to work in closed loop with functions M3 and
M4 to make the following adjustments on a spindle:
• Adjust the loop for M19.
• Adjust a loop for when the spindle is the master of a synchronization.
The axes usually work in closed loop. A rotary axis may be controlled in open loop as if it
were a spindle.
The following instructions may be used to open and close the loops and they are valid for
axes as well as for spindles.
#SERVO ON - Activates the closed loop mode.
#SERVO OFF - Activates the open loop mode.
#SERVO ON
Activates the closed loop mode
Programming this instruction switches the axis or spindle to closed loop mode.
The spindle must be homed before switching to closed loop mode; otherwise the loop will
be closed and a warning message will be issued.
The programming format is as follows:
#SERVO ON [axis/spindle]
The loop of each axis or spindle must be closed separately.
#SERVO OFF
Activates the open loop mode
Programming this instruction switches the axis or spindle to open loop mode. For a spindle,
it cancels the closed-loop mode programmed #SERVO ON and restores the status that the
spindle had before closing the loop.
• If the spindle was in M19, it stays in closed loop after programming this instruction.
• In spindle synchronization, the #SERVO OFF instruction cannot be programmed for the
slave spindle; if programmed, the CNC will issue an error message.
If the synchronization has been defined withe master spindle working in closed loop, it
stays in closed loop after programming #SERVO OFF. If the synchronization has been
defined with the master spindle working in open loop and, later on, it is closed with
#SERVO ON, the loop of the master spindle will be opened after programmming
#SERVO OFF.
• If the spindle was in M3, M4 or M5 without synchronism, the CNC opens the loop.
The programming format is as follows:
This function is not available for Sercos position-drives (axis or spindle). In this case, the CNC cannot
open or close the loop, the drive controls the loop, instead.
i
Parameter Meaning
axis/spindle Name of the axis or spindle.
#SERVO ON [S]
Closes the loop of spindle S.
#SERVO ON [S2]
Closes the loop of spindle S2.
#SERVO ON [X]
Closes the loop of the X axis.