
11. PROGRAM COMMAND
B–63523EN–1/03
1496
[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”, the tool retraces the tool path along which it was
moved. The tool does not start retrace immediately after this signal turns
to “1” ; the tool starts retrace after the current block. When RVS turns to
“0” while retrace is in progress, the tool switches from retracing to tracing
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. By first turning 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, the feed hold signal *SP and the automatic operation
start signal ST turn from “1” to “0”. 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 there is no block for 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, to
prevent these functions from being executed.
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.
Signal
Retrace signal RVS
<G007#0>
Retrace–in–progress
signal RVSL
<F082#2>