Data Display

Hi Good Day!

I am trying to make a data display that employ 20 characters. Since a character will take 4 PLC digital outputs, I will have to use 80 digital outputs!! Is there any programming method that can save the outputs to display the data?

Implement a multiplexer -

http://www.intersil.com/data/an/an054.pdf

Is it that just for testing purposes?

In this case you can try to build some simple circuit from CMOS 4094 (or similar) which can be easily attached into chain and it will need just three outputs (+5V only of course)... i used that to build long BCD LED Segment display.



Well... for industrial use, some more solid multiplexing solution will be better

If your PLC has a RS232 port maybe you shold consider to find a display with a RS232 interface. Then you need no outputs.