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Old April 24th, 2006, 07:41 AM   #1
fiona_n
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Question Programming in ladder logic

Hi, could someone please help me.

I want to write a program in ladder logic that operates like a joystick that will enable the user to either scroll up, down, left or right. (It is for a T100MD-1616 PLC)

Any help would be appreciated.
Fiona
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Old April 24th, 2006, 07:53 AM   #2
Steve Bailey
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First, you have to define your inputs and outputs. Inputs are the signals from the user. Outputs are the signals generated by the PLC program. Exactly what is going to scroll up, down, left, or right?
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Old April 25th, 2006, 08:34 AM   #3
fiona_n
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I have defined the inputs(sensors) and the outputs are displays (i.e frequency, temp, pulse etc). the problem i am having is that once the user presses the right button, say the freq is displayed, but then the user has the option to either press the right or left button and each button displays a different output. i cannot seem to program this.

could u help?
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Old April 25th, 2006, 08:50 AM   #4
Steve Bailey
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I gather that you have some sort of display that can show one value at a time and you want to give an operator the ability to scroll though all of the values.

First, how does the display decide which value to show? How is it connected to the PLC? I can think of a few methods. One method is a serial (or ethernet) connection between the display and the PLC. With this method, the PLC may send a numeric value to the display unit which shows that value. A variation of that is for the PLC to send a number and the display shows a message from its memory that corresponds to that number. Another method is to have some number of PLC discrete (on/off) outputs wired to the display. The display shows a message from its memory based on the pattern of signals. Another possibility is that the display unit is integrated with the PLC.

Tell us what you have and how it is supposed to work and we can point you in the right direction.

One reason that there have been no responses to this thread may be that you've only given a part number and not a manufacturer. By doing so, you've limited the pool of responders to people who recognize that part number.
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Old April 25th, 2006, 09:05 AM   #5
rsdoran
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I know part of it, the T100MD1616 http://www.tri-plc.com/t100md.htm
It has an LCD alphanumeric display 1-4 lines, 8-20 characters but no keypad for entry etc.

TriLOGI has a forum too and fiona has the question there but has not recieved an answer.

I have only dealt with TriLOGI once and that was years ago, I can not help until I look at the manual.
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Old April 26th, 2006, 01:42 AM   #6
ghettofreeryder
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Something Like this??

-( )-(ons)---------------------[CTU]-
Right Counter

-( )-(ons)---------------------[CTD]-
Left Counter

-[EQU]-------------------------[MOV]-
Counter=1 Value 1 >> Display

-[EQU]-------------------------[MOV]-
Counter=2 Value 2 >> Display



BTW.... How do i take a screen image to just display some rungs, do i just use Prnt Scrn and crop it?

Last edited by ghettofreeryder; April 26th, 2006 at 01:44 AM.
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Old May 8th, 2006, 02:51 AM   #7
fiona_n
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SetCtrSV and SetTimerSV

Thanks guys for all the help.

I have managed to get the LCD to work and allow the user to see the different outputs based on a certain input, but i am struggling to allow the user to change the displayed value i.e increase or decrease the temperature set point by a certain factor. I thought of trying either the SetCtrSV or SetTimerSV but i am not sure exactly how they work. Could u help?
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