Functional Sequence (Principle) - Siemens sinumerik 840D sl Function Manual

2.1.2

Functional sequence (principle)

Functional sequence
The principle sequence of the RESU function between the interruption point, program
continuation point and continuation of part program processing is described below:
1. Requirements:
2. Interrupt part program processing:
3. Select reverse travel:
4. Reverse travel:
5. End reverse travel:
6. Select forward travel (optional):
7. Forward travel (optional):
8. End forward travel (optional):
9. Retrace support:
10. Continuation of part program machining:
Special functions: Retrace Support (TE7)
Function Manual, 11/2006, 6FC5397-2BP10-2BA0
A part program with traversing blocks in the 1st and 2nd geometry axis as well as the part
program command for the RESU start has been started in the 1st channel.
The part program processing / traversing movement may be interrupted any number of
traversing blocks after RESU start by NC STOP.
The selection of the reverse travel is by PLC interface signal:
DB21, ... DBX0.1 = 1 (Forward/Reverse)
NC START initiates reverse travel along the contour in the first two geometry axes of the
channel. Instead of the current machining program, RESU selects the automatically
generated RESU main program. For more about RESU programs see Subsection
"Detailed description / RESU-specific part programs".
Once the required program continuation point on the contour has been reached, reverse
travel is ended using NC STOP.
For forward travel, reverse travel must be deselected via PLC interface signal:
DB21, ... DBX0.1 = 0
NC START initiates forward travel along the contour in the first two geometry axes of the
channel.
Once the required program continuation point on the contour has been reached, forward
travel is ended using NC STOP.
Continue machining is initiated via PLC interface signal:
DB21, ... DBX0.2 = 1 (start retrace support)
For retrace support, RESU automatically selects the original machining program and
launches a block search with calculation as far as the program continuation point.
Part program processing continues at the program continuation point in accordance with
the "Block search with calculation" standard function when two NC START commands
occur one after the other.
Detailed description
2.1 Functional description
9