B–63503EN–1/01
8. AUXILIARY FUNCTION
343
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.
3001#7).
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).
(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.
8.4
HIGH–SPEED M/S/T/B
INTERFACE
General
Basic procedure