How To Select A Seven-Segment Display Unit; How To Select Parameter "N" Based On Seven-Segment Display Specifications - Mitsubishi Electric FX3G SERIES Programming Manual

Programmable controllers

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Series Programmable Controllers

Programming Manual - Basic & Applied Instruction Edition

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:

1. Points to be checked for the seven-segment specifications

The input voltage and current characteristics of the data input and strobe signal satisfy the output specifications of

- The input signal voltage (Lo) is approximately 1.5 V or less

- The input voltage is from 5V DC to 30V DC

The seven-segment display unit has the BCD decoding and latch functions

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.

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. 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.

Output circuit

Negative logic

Sink output (− common)

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."

15 External FX I/O Device – FNC 70 to FNC 79

15.5 FNC 74 – SEGL / Seven Segment With Latch

→ For the wiring, refer to the Hardware Edition of the PLC used.

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."

Positive logic

Source output (+ common)

Fx3u series Fx3uc series