Mitsubishi Digital Electronics FX2N Manual

A SERVICE OF

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FX Series Programmable Controlers Applied Instructions 5

5-86

d) If the SEGL instruction is suspended durin

g

mid-operation, when it is restarted it will start

from the be

g

innin

g

of its c

y

cle and not from its last status achieved.

e) The SEGL instruction ma

y

be used

ONCE

on FX controllers with CPU versions lower than

3.07. FX units with CPU ver 3.07 or

g

reater and all FX

2C

units can operate a maximum of

TWO

SEGL instructions.

Selecting the correct value for operand n

The selection of parameter n depends on 4 factors;

1) The lo

g

ic t

y

pe used for the PLC output

2) The lo

g

ic t

y

pe used for the seven se

g

ment data lines

3) The lo

g

ic t

y

pe used for the seven se

g

ment strobe si

g

nal

4) How many sets of displays are to be used

There are two t

y

pes of lo

g

ic s

y

stem available, positive lo

g

ic and ne

g

ative lo

g

ic. Dependin

g

on

the t

y

pe of s

y

stem, i.e. which elements have positive or ne

g

ative lo

g

ic the value of n can be

selected from the table below with the final reference to the number of sets of seven se

g

ment

displa

y

s bein

g

used:

Device considered Positive logic Negative logic

PLC Logic

With a source output, when the

output is HIGH the internal lo

g

ic is ‘1’

With a sink output, when the output

is LOW the internal lo

g

ic is ‘1’

Seven

segment

Display

logic

Strobe

si

g

nal lo

g

ic

Data is latched and held when this

si

g

nal is HIGH, i.e. its lo

g

ic is ‘1’

Data is latched and held when this

si

g

nal is LOW, i.e. its lo

g

ic is ‘1’

Data

si

g

nal lo

g

ic

Active data lines are held HIGH,

i.e. the

y

have a lo

g

ic value of ‘1’

Active data lines are held LOW, i.e.

the

y

have a lo

g

ic value of ‘1’

PLC Logic

Seven segment display logic n

Data Logic Strobe logic 1 display set 2 display sets

Positive

(Source)

Positive

(High)

Positive

(High)

04

Ne

g

ative

(Sink)

Ne

g

ative

(Low)

Ne

g

ative

(Low)

Positive

(Source)

Positive

(High)

Ne

g

ative

(Low)

15

Ne

g

ative

(Sink)

Ne

g

ative

(Low)

Positive

(High)

Positive

(Source)

Positive

(High)

Ne

g

ative

(Low)

26

Ne

g

ative

(Sink)

Ne

g

ative

(Low)

Positive

(High)

Positive

(Source)

Positive

(High)

Positive

(High)

37

Ne

g

ative

(Sink)

Ne

g

ative

(Low)

Ne

g

ative

(Low)

V+

0V

Y

+V1

HIGH

Pull-down

Source output

COM

Y

V+

0V

LOW

Pull-up

resistor

Sink output