11. PROGRAM COMMAND
B--63003EN--1/02
1008
[Classification] Input signal
[Function] Directs the control unit to retrace the tool along the path which the tool
was moved in automatic operation (memory command, tape command,
manual data input).
[Operation] When RVS turns to “1” while the tool is being moved forward (hereafter
referred to as forward), the tool retraces the tool path along which it was
moved. Note, however, that the tool does not start retrace immediately
after this signal turns to “1” ; the tool starts retrace after the block
performing the current forward operation is executed. When RVS turns
to “0”while retraceis in progress, thetool switches from retrace operation
to re--forward. In this case also, the tool does not start re--forward to
resume machining immediately after this signal turns to “0” retrace; the
tool starts re--forward after retracing all commands of the block currently
subject to retrace.
The movement of a tool can be immediately switched from forward to
retrace or from retrace to re--forward. For this purpose, first turn the feed
hold signal *SP to “0” to stop automatic operation. Then, change the state
of RVS after the automatic operation start in--progress signal STL turns
to “0” and the automatic operation stop state is set. And the feed hold
lamp SPL turns to “1”. Next, turn feed hold signal *SP the automatic
operation start signal ST from “1” to “0” to start automatic operation.
Then, the tool can switch its movement to retrace or re--forward during
execution of a block.
[Classification] Output signal
[Function] Notifies the PMC that retrace is in progress.
[Output condition] This signal turns to “1”when:
· Tool is in retrace with the retrace signal RVS turned to “1”.
This signal turns to “0”
· The tool is in forward or re--forward with the retrace signal RVS turned
to “0”.
· The tool is at stop because of no block to retrace during retracing.
When the tool is in retrace, the M functions, S functions, T functions, and
second auxiliary functions are executed in the same way as when the tool
is moving forward. During retrace, this signal can be used on the PMC, if
required, to prevent these functions from being executed in the same way
as when the tool is moving forward.
Particularly when an M function, S function, T function, or second
auxiliary function is specified in a block containing a move command, the
positions where the code signals and strobe signal are output differ,
depending on whether the tool is in forward (or re--forward) or retrace. So,
take action on the PMC by using this signal and distribution end signal
DEN as required.
Signal
Retrace sign al (RVS)
<G007#0>
Retrace--in--progress
signal (RVSL)
<F082#2>