Siemens SIMATIC FM 351 - Page 102

Modes and Jobs
9-16
FM 351 Positioning Module
C79000-G7076-C351-02
Table 9-3 Options for a Reference Point Approach, continued
Conditions for a Reference Point Approach Sequence of a Reference Point Approach
Example of a reference point approach
(REFPT_TYPE=1):
• Start direction is plus.
• Position of the zero marker from the reference
point switch is set in the minus direction.
• Start position for the reference point approach
is at the reference-point switch.
-v
creep
REF
SYNC
N
Start position
Example of a reference point approach
(REFPT_TYPE=0):
• Start direction is plus.
• Position of the zero marker from the reference
point switch is set in the plus direction.
• The reverse switch is more positive than the
reference-point switch.
R
v
creep
REF
REV
SYNC
R
N
Start position
-v
creep
v
rapid
–v
rapid
Example of a reference point approach
(REFPT_TYPE=0):
• Start direction is plus.
• Position of the zero marker from the reference
point switch is set in the plus direction.
• Start speed = creep speed
v
creep
REF
SYNC
N
Start position
R = Direction
reversal
REF = Reference-point
switch
REV= Reversing
switch
Z = Encoder zero mark
SYNC = Synchronization was achieved.