
B–62073E–1/04 2. INTERFACE BETWEEN CNC AND PMC–NA OR NB
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Command block
(Input)
PMCAx (Input)
Command disable
CNCAx (output)
Execution
waiting
buffer
Executing
register
[1] [2] [3] [4]
[1] [2]
Start End Start
The buffer state of the CNC can be known by exclusive ORing PMCAx axis control command read strobe
signal input from the PMC with CNCAx (axis control command read completion signal) output from the
CNC.
PMCA
/
CNCA
Exclusive OR(XOR)
Status of CNC side
01
//
01
0
Since the reading of the previous command block has ended,
the next block can be commanded
01
//
10
1
The buffer is full and it is not possible to read the command
from the PMC side. Do not inverse the signal PMCAx. When it
is inversed in this status, the blocks which have been comman-
ded become invalid.
4 Repeat steps 2 and 3 for each command block.
When the transfer and execution of commands for the last block completes, set PMC axis control signal
PCAXx low.
PCAXx must be set low after the block being executed and the block pending in the buffer are completed.
If PCAXx goes low when there is a block being executed or pending in the buffer, the remaining commands
in the block being executed and the pending–command buffer are all cleared and the CNC immediately
regains control.
When the buffer is empty, buffer full signal BUFx is off. When there are no blocks being executed, distribu-
tion completion signal DENx is on.
For axes which control a turret, pallet, or ATC, axis control is always carried out by the PMC without switch-
ing the control between the CNC and PMC. In this case, PCAXx must always go high; it is not necessary
to set it low even when all commands have been transferred.
After all specified blocks have been executed and there are no blocks to be executed, operation automati-
cally completes.
5 When PCAXx goes low, the CNC regains control.