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Analog Output FT1A-C14SA Messages in this topic - RSS

Brady
Brady
Posts: 4

8/13/2019
New member, first post. Hope some one here can help me. I did partially learn what to do by reading the manuals.

My back ground is an electrician at a food plant, just now starting to dabble in the world of PLC/Programming. I have a good sense of ladder logic and control systems, but the programming of the Analog Output has me stuck. I am building a test box for testing mix proof valves that are modulated with an 4-20ma output. I have used a signal generator in the past, but this little PLC will let me test every type of the 5 valves except mod bus. So far I can get all my DI's and DO's, and program to load and run flawlessly (special shout out to "Control Freak" on YouTube for his informative videos).


Here is what I have done so far:
Configured analog output AQ0 for 4-20ma
Added a Potentiometer on one of my base touch screen and assigned the following:

Data type: BIN 16+
minimum: 0
maximum: 1000
destination device: #D8044
target: internal
device type: #D Control Function Data Register
Address: 0

When I go to program the ladder logic, I am just not sure what to do. I think I have to add a Data Register Compare (DC=) ? and assign similar settings as above, but I just can not see to complete the logic to make this work.

Any suggestions are appreciated.

Thank you in advance for your help.
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Shane
Shane
Moderator
Posts: 306

8/13/2019
First, the FT1A will do Modbus as well if you need it. May be a little more tricky for you to set up initially as a beginner but it's capable.

Next, looks like you've basically done it correctly but where you lost it, I think, was after "target: internal". You say the destination device is #D8044 but then below that you say "Address: 0" that would change the 8044 to 0, and you probably don't want that. If you set the destination device to #D8044 the potentiometer you created on the HMI will write directly to the physical output AQ0.

If all you want to do is use the FT1A as an analog test output you shouldn't need to do anything else. 0-1000 is the proper scale for the analog output AQ0 so moving the pot from 0-100% should give you full span from 4-20mA.

Date Register Compare, DC=, is just used to compare two registers and turn on a bit. You can do the same with Load Compare LC and Compare CMP but you didn't specify if and why you'd be wanting to turn on a bit from the analog value.
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Brady
Brady
Posts: 4

8/14/2019
Excellent. Thank you for helping me. I will make the change and test it out. I was thinking that I had to write something in the ladder logic to make the AO work properly.
So if I wanted a numerical display, I could add a "Numerical Display" to the touch and assign it to #D8046 ?
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Shane
Shane
Moderator
Posts: 306

8/15/2019
Why #D8046? What do you want the numerical display to show?
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Brady
Brady
Posts: 4

8/29/2019
Thank you for your help, finally had time to get this one figured out and working, I was trying to display a numerical value of the potentiometer, (0 to 100) I used #D8044 as the display reference and had to change the display with arithmetic operation to @ / 10 (since D8046 is 0-1000).
What if I wanted to add 4 push buttons and when the buttons were pushed it would give me 0%/25%/50%/100% output to Analog output? From what I read so far, i would need to some logic programming, and trigger an internal relay. I really need to catch the next IDEC class when they are back in Texas to get better at this.
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Shane
Shane
Moderator
Posts: 306

9/4/2019
No logic needed for that one either. On the HMI just make 4 word buttons and have them "Set" xx value to destination #D8044. Make 4 buttons and the set values will be 0, 25, 50, 75, and 100. When you push each button it will write the value to the destination.
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Brady
Brady
Posts: 4

9/8/2019
Thank you for all your help.
This project turned out very well.
Here are some photos to show what I did.
Looking for the next one, thank you for all the learning.




edited by Brady on 9/8/2019
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Shane
Shane
Moderator
Posts: 306

9/11/2019
Excellent, glad it worked out.
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