Mitsubishi Electric Melsec-k Instruction Manual page 38

1
4, PROGRAMMING
I ! J EL8EEbK
4.4.3 Prograrnrr) ing instructions
If communication is interrupted in the optical data link system,
1
Master channel [=Data, which has been received last, are retained.
I
Remote I/O channel All outputs are turned off,
I
Local channel
1
=Depending on circumstances, received data are retained or cleared.
As indicated above, the results depend on channels. For the sake of fail safe, therefore, it is recommended
to set an interlock condition in the program.
Master Channel
Data link start signal
MC K1
K1
---
I
i
Control probram by link data
M C R K l '
Data link start
Local Channel Number 1 (KOJIP)
I - L
T K1
I
Local Channel Number
2
(K3NCPl.J'
MA2 0 MA21
4 )
I
I - L
T
K1
1
1
YlOO ON
7
>
>
X I 4 0 ON Y1 DO ON
>
Y120 0 N - Z X120 ON
HOLD
sw3
YlOO ON
Number 1 Number 2
machine machine
normal
XlOO ON X190 ON
abnormal
x i 0 0 OFF X I 9 0 OFF
Data link
M I OON
Disconnected operation
SW1 ON SW2 ON
J/
MCKl
During data link, output i s provided
to Number 1 machine by Y120 and
to Number 2 machine by Y I D and
each local channel returns normal
signal by YlOO i f
it
receives normal-
ly. In the master channel, receipt of
normal signal activates MC to allow
control program processing b link
data. However, when the RUNYSTOP
switch of local channel i s moved to
STOP position, the return signal from
!oca1 channel i s turned off, resulting
in disconnected state. I f disconnected
operation i s pedormed in this state
turning on SW1 and SW2 permit;
control program processing by link
data continuously i f the content of
DA06 is 0 (no error in local system
transmission system). To process the
control program by link data of
master channel although there is an
error channel, turn on SW3. (See
Section 4.4.2.)
I
When link i s normal X I
20 (Y 120
of
master channel) i s {urned on wh'ich
turns on YIOO. When YlOO iiturqed
on XlOO in the master channel i s
tuined on, which allows the checking
that the link system between both
channels i s normal.
During normal link, M250 and M251
are off. Therefore check off of both
coils and process the control program
by link data. (See Section 4.4.1.)
l
When link i s normal, X I 4 0 (Y 1 DO of
master channel) i s turned on which
turns on Y100. When YlOO iiturned
on, X190 in the master channel i s
turned on, which allows the checking
that the link system between both
channels i s normal.
During normal link, MA20 and MA21
are off. Therefore check off of both
coils and process the control program
by link data. (See Section 4.4.1.)
/ /