Direct Soft Programming

[DRATCLIFFE]

I AM WRITTING A PROGRAM FOR DIRECT SOFT 32

1.A PUMP SPEED CAN BE CONTROLLED MANUALLY AS A PERCENT BY TWO THUMB WHEELS SWITCH SETTINGS.

2.ANALOG OUTPUT PROPORTIONAL TO THE THUMB WHEEL SETTING. 00 ON THE THUMB WILL BE 0 VOLTS AND 99 WILL BE 9.9 VOLTS

3.IF THE PUMP IS RUNNING AT 75% OR HIGHER IT WILL TURN ON A INDICATOR LIGHT.

 

[thierry2003]

Congratulations. Is the program working alright?
Seriously, you can't expect people to write the program for you.
Give it a shot, show what you've got and the ask questions....

Good luck

 

[dandrade]

Only they wrote a program to you will go a challenge. Somewhat well explained, and an unusual situation.. Not necessarily complex, the help will be guaranteed and amused the participants

 

[ArikBY]

I am new to AD PLCs too so I will try to do with you this exercise.
Let decide what we need before.
I think we need 8 inputs,1 output and 1 analog output.
Do you agree?
How do you think we should convert the thumg wheel signal to numbers?
2 digit number.
Think obout that come with an answer and we will go to the next step.

 

[elevmike]

Question,

I've never worked with thumbwheels before. Do they put out a binary, BCD, or grey code signal or something like that?

 

[ArikBY]

Most of them work as binary some as BCD.
I assume it binary.
I never see thunbwheel with gray code.

 

[elevmike]

Thanks ArikBY,

Ok so lets presume that the tuumb wheels are BCD just to keep things simple, You would take the tuumb wheel value, and mutlaply it by your proportanate value, and out the result directly into your refrence location for the Analog Output module. Your indicaator could simply work by using a comparitve contact (Thumbwheel > K75). Seems pretty simple to me. You didnt mention the model PLC, or analog unit etc.. So who knows what memory locations are involved....

Mike.

 

[Thomas Sullens]

2.ANALOG OUTPUT PROPORTIONAL TO THE THUMB WHEEL SETTING. 00 ON THE THUMB WILL BE 0 VOLTS AND 99 WILL BE 9.9 VOLTS

3.IF THE PUMP IS RUNNING AT 75% OR HIGHER IT WILL TURN ON A INDICATOR LIGHT.

The first thing you have to do is setup your hardware, so you will know what your inputs and outputs will be. When using a DL205 system your analog card has to start on a file boundary.( Example ) slot 1 16 bit card X0 THRU X17 slot 2 comb. Analog card F2-4AD2DA it would take X20 THRU X37 AND Y 0 THRU Y 17. Slot 3 out put card Y 20 thru Y 27 the thumb wheel switch will be wired to slot 1 X0 and so on the value of this input card or word will be in word V40400 in your processor. This is your discrete input it really exists. Now you take the value of V40400 and scale it to where 0 to 99 will show up in the analog out as 0 to 4095. As for as turning on your light you could use a compare statement to do this. If this were a real project you would need to get an Analog I/O Manual for whatever type system you were going to use so you could set it up. On the new processors you may not have to set them up. I don`t know. This is probably as clear as mud, but I hope it helps.

Have a nice day.
Tom

 

[DRATCLIFFE]

THE THUMB WHEELS ARE BCD

I THINK I HAVE THE BCD FIGURED OUT


(SCALED_MAX - SCALED_MIN)
SCALED = ( -------------------------
(RAW - RAW_MIN) )

*(RAW_MIN - RAW_MIN)+ SCALED_MIN


I THINK THIS WILL GIVE ME THE CORRECT PROGRAM SEQUENCE

THANKS FOR YOUR HELP

 

[DesertDog]

Thumb Wheel switches are setup for BCD, however I used to get the electrical drawn by someone that re-ordered the inputs to make his drawings simpler. This meant I could either decode the inputs as individual inputs and the sequence that stood for a specific digit, as the code I had to look at had done or move the input bits into a correct ordered sequence of memory bits and then use a BCD conversion to get the number as I started to do as the projects grew in size.