
8.MISCELLANEOUS FUNCTION B-63783EN-1/01
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8.4 HIGH-SPEED M/S/T/B INTERFACE
General
To accelerate M/S/T/B function execution, the high-speed M/S/T/B
interface has simplified the transfer of the strobe and completion
signals of the M/S/T/B functions.
Whether to use the usual system or high-speed system for strobe signal
and completion signal handling can be specified by parameter MHI (No.
2004#0).
The description below uses the miscellaneous functions (M code
commands) as an example. The same description applies to the
spindle-speed function (S code), tool function (T code) and 2nd
auxiliary function (B code).
- Basic procedure
(1) Assume that the following program is given:
Mxx;
Myy;
(2) In response to an M command, the NC system sends out the code
signals M00 to M31.
The NC system inverts the logical level of the strobe signal MF,
that is, from "0"to "1", or from "1" to "0".
(3) The CNC system inverts the strobe signal, then when the logical
level of the auxiliary function completion signal MFIN becomes
the same as the strobe signal, the CNC assumes the completion of
PMC sequence.
With the usual method, the operation is assumed to be completed
when a falling edge ("1" to "0") of the M/S/T/B completion signal
FIN is received after a rising edge ("0" to "1") of the FIN signal is
detected. This new system, on the other hand, assumes the
operation has been completed upon detection of only one
transition of the completion signal.
In addition , the usual system uses only one completion signal
(FIN) common to the M/S/T/B functions. This new system uses a
different completion signal for each of the M, S, T, and B
functions; the completion signals for the M, S, T, and B functions
are MFIN, SFIN, TFIN, and BFIN, respectively. The Fig. 8.4 (a)
below shows the timing chart of these signals with the new system.
For comparison, Fig. 8.4 (b) shows the timing chart of the
conventional system.