FX Series Programmable Controlers Applied Instructions 5
5-85
5.8.5 SEGL (FNC 74)
Operation:
This instruction takes a source decimal value (S)
and writes it to a set of 4 multiplexed, outputs (D).
Because the lo
ic used with latched seven
se
ment displa
s varies between displa
manufactures, this instruction can be modified to suit
most lo
ic requirements. Confi
urations are selected dependin
on the value of n, see the
followin
pa
e.
Points to note:
a) Data is written to a set of multiplexed outputs (D
+0
to D
+7
, 8 outputs) and hence seven
se
ment displa
s. A set of displa
s consists of 4 sin
le di
it seven se
ment units. A
maximum of two sets of displa
s can be driven with this instruction. When two sets are used
the displa
s share the same strobe outputs (D
+4
to D
+7
are the strobe outputs). An
additional set of 4 output devices is required to suppl
the new data for the second set of
displa
s (D
+10
to D
+13
, this is an octal addition). The strobe outputs cause the written data to
be latched at the seven se
ment displa
.
b) Source data within the ran
e of 0 to 9,999 (decimal) is written to the multiplexed outputs.
When one set of displa
s are used this data is taken from the device specified as operand
S. When two sets of displa
s are active the source device S
+1
supplies the data for the
second set of displa
s. This data must a
ain be within the ran
e 0 to 9,999. When usin
two sets of displa
s the data is treated as
two
separate numbers and is
not
combined to
provide a sin
le output of 0 to 99,999,999.
c) The SEGL instruction takes 12 pro
ram scans to complete one output c
cle re
ardless of
the number of displa
sets used. On completion, the execution complete fla
M8029 is set.
Mnemonic Function
Operands
Program steps
SD n
SEGL
FNC 74
(
Seven
se
ment
with latch)
Writes data to
multiplexed sin
le
di
it displa
s - 4
di
its per set,
max. 2 sets
K, H
KnX, KnY,
KnM, KnS
T, C, D, V, Z
Y
Note:
n = 0 to 3, 8
outputs are
used
n = 4 to 7, 12
outputs are
used
K, H,
Note:
n= 0 to 3, 1 set
of 7 Se
active
n= 4 to 7, 2 sets
of 7 Se
active
SEGL:
7 steps
X0
D 0 Y 0 K 4SEGL
[ D ][ S ] [ n ]
10101010
3012
Y2 Y3+V0 Y0 Y1 Y6 Y7+V1 Y4 Y5 Y12 Y13+V2 Y10 Y11
1248
10
10
1010
30
1
2
V+
V+
1
2
4
8
1
2
4
8
1248
Transistor Output (Source)
BCD
data
signals
Display set 2
Display set 1
In this example it has
been assumed that the
seven se
ment displa
s
accept data HIGH inputs
and latch when a HIGH
si
nal is received
Note: A sin
le set of strobe si
nals are alwa
s used
re
ardless of the number of displa
sets.
