thumb wheel switch

[saleem patel 0]

how to program a thumb wheel switch with delta plc using isp sowftware 

[IvanBratanov 6]

First you have to find out the thumbwheel switch output’s coding system (binary, decimal, hexadecimal). Then you have to find the output’s polarity (common anode or common cathode) in order to connect it proper to the PLC’s inputs. Each digit of the thumbwheel switch has 4 outputs. So you have to use inputs X0-X3 of the PLC for the first digit, X4-X7 for the second digit etc.

For the first digit (if the thumbwheel switch has binary outputs) you may use MOV instruction in format with Kn value to modify the input values:

LD M1000
MOV K1X0 D0

 

The instructions above will continuously convert the states of the X0-X3 inputs and store the result in D0. So D0 will contain the first digit of the thumbwheel switch (if the first digit of the switch is 1, the value in D0 will be 1 as well).
 

The situation for the other digits will be similarly.

Edited 10 Sep 2023 by IvanBratanov

[BobLfoot 303]

IT is old school and time consuming to code, but if you are input limited, but do have 4 inputs and some spare outputs you can diode isolate the same output of each switch and use one input for all 1st output of all switches.  you then poser one switch at a time and after powering the switch read the inputs it generates and then move to the next switch.  Had to do this once on an old omron system that only had 5 spare inputs left but an entire 16 bit bak of outputs spare.

[IvanBratanov 6]

10 hours ago, BobLfoot said:

IT is old school and time consuming to code, but if you are input limited, but do have 4 inputs and some spare outputs you can diode isolate the same output of each switch and use one input for all 1st output of all switches.  you then poser one switch at a time and after powering the switch read the inputs it generates and then move to the next switch.  Had to do this once on an old omron system that only had 5 spare inputs left but an entire 16 bit bak of outputs spare.

Its widely used even today when for example large quantity of 7-seg numbers have to be driven by limitd number of PLC outputs. Each number is illuminated for a fraction of second with its value, then the next etc. When the last digit is illuminated it starts back with the first one. Because of the high switching speed all the digits seem to be illuminated at the same time for the eye.

[IO_Rack 193]

BobLfoot

I'm calling you The Pinball Wizard from now on! LOL