Program-Controlled Reference Point Approach - Siemens SINUMERIK 840C Installation Instructions Manual

07.97
2nd case: Axis is at the reference point cam
Speed
MD 284*
Reference point
Axis is at reference point cam
When the Direction key is pressed, the PLC's "Deceleration" signal enables the NC to
d
establish with absolute accuracy that the axis is already located at the reference point
cam. The axis therefore accelerates in the reverse direction (MD 564* bit 0) to the speed
defined in MD 284* (refer to Section REFERENCE POINT APPROACH WITHOUT
AUTOMATIC DIRECTION RECOGNITION for a detailed description of the remaining
portion of the sequence).
10.4.4.3

Program-controlled reference point approach

Reference point approach can be executed in a part program with G74. When MD 1808*, bit 4,
is set, reference point approach to the coded reference marks is executed automatically. The
direction is defined in MD 564*, bit 0, and not with the direction keys.
Example:
AUTOMATIC or MDA mode
L F
N10 G74 X
Note:
From SW 5, simultaneous referencing of up to 5 axes is possible.
Example:
N10 G74 X Y Z U V
© Siemens AG 1992 All Rights Reserved
SINUMERIK 840C (IA)
2000 units
Reference point cam
Reference point pulse
L F
6FC5197- AA50
10 Axis and Spindle Installation
10.4.4 Reference point approach
d
EMERGENCY
STOP
Traversing limit
Path
10–39