Siemens SINUMERIK 840D sl Function Manual page 1557

Aborting reference point approach
In channel-specific reference point approach the machine axis is traversed in the channel to
which that axis is currently assigned as channel axis.
For aborting the reference point approach either mode group reset or channel reset for the
corresponding channel must be activated:
DB11, ... DBX0.7 (mode group reset)
DB21, ... DBX7.7 (channel reset)
All machine axes for which the reference point approach is not yet successfully completed
when the action is cancelled remain in the status "Not referenced":
DB31, ... DBX60.4 (referenced / synchronized 1)
DB31, ... DBX60.5 (referenced / synchronized 2)
2.3 Reference point appraoch from part program (G74)
Referencing of machine axes can be activated for the first time or repeated from the part
program
Referencing must be repeated, for example, after:
• converting the actual value of the machine axis: PRESETON function
• Machine axis is parked:
• DB31, ... DBX2.1 (servo enable) = 0
• Exceeding the encoder limit frequency of the position measuring system
Programming
Syntax
G74
Function
Machine axes can be referenced from a part program with part program instruction G74
Parameter:
The name of the machine axis must be specified. The machine axis must be a channel axis
of the channel in which the part program is processed.
Effective:
G74 is non-modal.
Special points to be noted
G74 must be programmed in a separate part program block.
Basic logic functions: Reference Point Approach (R1)
Function Manual, 11/2006, 6FC5397-0BP10-2BA0
DB31, ... DBX1.5 (Position measuring system 1) = 0
DB31, ... DBX1.6 (Position measuring system 2) = 0
Machine axis Machine axis
{
Machine axes
2.3 Reference point appraoch from part program (G74)
}
Detailed description
11