Reference Point Approach Without Automatic Direction Recognition; Reference Point Approach With Automatic Direction Recognition - Siemens SINUMERIK 840C Installation Instructions Manual

10 Axis and Spindle Installation
10.4.4 Reference point approach
10.4.4.2 Reference point approach with automatic direction
recognition
Prerequisites
• MD 560* Bit 6 = 1
• Feed enables set
• Reference point cam extends as far as the traversing limit
• Reference point is ahead of reference point cam
The purpose of automatic direction recognition is to eliminate the problems caused by
reference point approach without automatic direction recognition in situations such as those
presented in case 3.
1st case: Axis is ahead of the reference point cam
Speed
MD 296*
MD 284*
a
Reference point
Axis is ahead of reference point cam
When the direction key is pressed, the axis approaches the reference point in the
a
specified direction (MD 564* bit 0) at the speed defined in MC 296*.
Upon reaching the reference point cam, the axis is decelerated to zero speed with the
b
"Deceleration" signal.
The axis then moves away from the reference point cam at reverse speed (MD 284*)
c
and the next reference pulse is evaluated (refer to Section REFERENCE POINT
APPROACH WITHOUT AUTOMATIC DIRECTION RECOGNITION for a detailed
description of the remaining part of the sequence).
10–38
2000 units
Reference point cam
EMERGENCY STOP
Reference point pulse
© Siemens AG 1992 All Rights Reserved 6FC5197- AA50
12.93
b
c Path
Traversing limit
SINUMERIK 840C (IA)