
B–61863E/15
3. DISPLAYING PMC INPUT/OUTPUT
SIGNALS AND INTERNAL RELAY
(PMCDGN)
PMC–NB6 MANIPULATION
675
Ex2: I/O UNIT–MODEL A is connected with X0. And X0 is forced
to be changed.
The input value from a I/O UNIT–MODEL A is periodically
transferred to X0. Therefore, even if you change the value of X0
forcedly, the I/O UNIT–MODEL A would overwrite the input
value at next cycle.
I/O Unit–MODEL A
NC
X0 = FFh X0 = FFh
X0 is forced to 00h
X0 = 00h
X0 is overwritten by the I/O Unit–MODEL A.
I/O Unit–MODEL A
NC
X0 = FFh X0 = FFh
The cyclic transfer might be performed to the addresses at which any I/O
device is not assigned. So, you should use the forced I/O function in the
forcing mode without I/O devices when debugging any X addresses. As
for the debug of the ladder program with I/O devices, use the forced I/O
function in Override mode explained in next paragraph.