Siemens SINUMERIK 840D sl Programming Manual page 700

Motion synchronous actions
10.4 Actions in synchronized actions
Example
Program code
$A_IN[1]==0 DO TRAILON(Y,V,1)
$A_IN[2]==0 DO TRAILON(Z,W,-1)
G0 Z10
G0 Y20
...
G1 Y22 V25
...
TRAILOF (Y,V)
TRAILOF (Z,W)
Example of conflict avoidance with TRAILOF
The coupled axis is released again for access as a channel axis by invoking the TRAILOF
function for the axis. It must ensure that TRAILOF is executed before the channel
requests the axis involved. However, this is not the case in this example
...
N50 WHEN TRUE DO TRAILOF(Y,X)
N60 Y100
...
In this case, the axis is not released early enough because the non-modal synchronized
action becomes active synchronously with N60 with TRAILOF, see section, Motion-
synchronous action, "Structure, basic information".
To avoid conflict situations the following procedure
should be followed.
...
N50 WHEN TRUE DO TRAILOF(Y,X)
N55 WAITP(Y)
N60 Y100
700
Comments
; Activation of the 1st coupled motion group
if the
digital input is 1
; Activation of the 2nd coupled axis group
; Infeed Z and W axes in the opposite ;axis
direction
; Infeed of Y and V axes in same axis
direction
; Superimpose dependent and independent
;movement of coupled motion axis "V"
; Deactivate 1st coupled axis group
; Deactivate 2nd coupled axis group
Programming Manual, 06/2009, 6FC5398-2BP20-0BA0
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