Mitsubishi Electronics FX3G User Manual
437
FX
3S
/FX
3G
/FX
3GC
/FX
3U
/FX
3UC
Series
Programming Manual - Basic & Applied Instruction Edition
15 External FX I/O Device – FNC 70 to FNC 79
15.5 FNC 74 – SEGL / Seven Segment With Latch
11
FN
C30
-FN
C3
C30
-FN
C3
9
R
ota
tion and
Shi
ft
ft
12
FN
C40-FN
C40-FN
C49
D
ata O
perati
perati
on
13
FNC
50-FNC
59
High-Speed
Proc
essing
14
FM
C60-FN
C60-FN
C69
H
andy
In
struction
15
FN
C70-FN
C70-FN
C79
E
xternal
F
X
I/O
De
vice
16
FNC
80-FNC
89
External
FX
Dev
ice
ice
17
FNC1
00-
FNC10
00-
FNC10
9
Dat
a
a
Transfer 2
18
FNC1
10-
FNC139
FNC139
Fl
oati
ng Poi
nt
19
FNC14
0-F
N
C
149
Da
ta
Operation 2
20
FNC1
50-
FNC159
FNC159
Pos
itioning
itioning
Control
15.5.1 How to select a seven-segment display unit
When selecting a seven-segment display unit based on its electrical characteristics, refer to the manual below:
→ For the wiring, refer to the Hardware Edition of the PLC used.
1. Points to be checked for the seven-segment specifications
1) The input voltage and current characteristics of the data input and strobe signal satisfy the output specifications of
the PLC.
- The input signal voltage (Lo) is approximately 1.5 V or less
- The input voltage is from 5V DC to 30V DC
- The input voltage is from 5V DC to 30V DC
2) The seven-segment display unit has the BCD decoding and latch functions
15.5.2 How to select parameter "n" based on seven-segment display specifications
The value set to the parameter "n" varies depending on the signal logic of the seven-segment display. Select "n" as
described below.
The check column is provided at the bottom of the table. Check a corresponding type of logic (positive or negative),
and utilize it for parameter setting.
described below.
The check column is provided at the bottom of the table. Check a corresponding type of logic (positive or negative),
and utilize it for parameter setting.
1. Role of the parameter "n"
The parameter "n" should be determined according to the data input logic (positive or negative) of the seven-segment
display unit, the logic (positive or negative) of the strobe signal and the number of sets of 4 digits to be controlled (1 or
2).
display unit, the logic (positive or negative) of the strobe signal and the number of sets of 4 digits to be controlled (1 or
2).
2. Checking the output logic of the PLC
Transistor outputs in PLCs are classified into the sink output type and source output type. The table below shows the
specifications for each type.
specifications for each type.
Logic
Negative logic
Positive logic
Output type
Sink output (
− common)
Source output (+ common)
Output circuit
Description
Because transistor output (sink) is provided, the output
becomes low level (0 V) when the internal logic is "1 (ON
output)". This is called "negative logic".
becomes low level (0 V) when the internal logic is "1 (ON
output)". This is called "negative logic".
Because transistor output (source) is provided, the output
becomes high level (V+) when the internal logic is "1 (ON
output)". This is called "positive logic".
becomes high level (V+) when the internal logic is "1 (ON
output)". This is called "positive logic".
Check
ON
PLC
LOW
Logic 1
Pull-up
resistor
COM1
Y000
ON
PLC
Logic 1
Pull-
down
resistor
V+
HIGH
+V0
Y000