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Programming manual
CNC 8055
CNC 8055i
4.
REFERENCE SYSTEMS
·M· & ·EN· MODELS
SOFT: V02.2X
Machine reference (Home) search (G74)
4.2 Machine reference (Home) search (G74)
The CNC allows you to program the machine reference search in two ways :
• Machine reference (home) search of one or more axes in a particular order.
G74 is programmed followed by the axes in which you want to carry out the reference search.
For example: G74 X Z C Y.
The CNC begins the movement of all the selected axes which have a machine reference switch
(machine axis parameter "DECINPUT") and in the direction indicated by the axis machine
parameter "REFDIREC".
This movement is carried out at the feedrate indicated by the axis machine parameter
"REFEED1" for each axis until the home switch is hit.
Next, the home search (marker pulse or home) will be carried out in the programmed order.
This second movement will be carried out one axis at a time, at the feedrate indicated in the axis
machine parameter "REFEED2" until the machine reference point is reached (i.e. the marker
pulse is found).
• Home search using the associated subroutine.
The G74 function will be programmed alone in the block, and the CNC will automatically execute
the subroutine whose number appears in the general machine parameter "REFPSUB". In this
subroutine it is possible to program the machine reference searches required, and also in the
required order.
In a block in which G74 has been programmed, no other preparatory function may appear.
If the machine reference search is done in JOG mode, the part zero selected is lost. The coordinates
of the reference point indicated in the machine axis parameter "REFVALUE" is displayed. In all other
cases, the active part zero will be maintained and the CNC will display the position values with
respect to that part zero.
If the G74 command is executed in MDI, the display of coordinates depends on the mode in which
it is executed : Jog, Execution, or Simulation.