RTDs and AB

Can someone explain how to address a board input that connects RTDs to a A/B 5/03 system and an example of how to write program for one of these.
I need to interface with 8 RTDs and display the readings on a touch screen.
My experiance is limited using analog but I do understand basically what analog versus digital means.

I have searched the site here and found some information about RTDs but it did not explain in the simple form that newbies like me can comprehend.it was good reading but not exactually answering my question(s)
Maybe I did not do a good search with the correct keywords.

any information that can be supplied will be helpful.

thanks,

A visit to AB.com would be helpfull to you. There you can download the manual for the 1746-NR8 module which is the interface module for RTD to SLC500. The manual is pretty good as far as AB manuals go with plenty of examples to get you started with the project.

It is not that hard to set the module up and obtain the data you require.

You need a 1746-NR8 resistance input card.

when installed and added to the hardware list you will get an input and output data table for each RTD input.

You basically set the card up by outputing a binary code (its in the manual) to configure the module to do what you want.

Then the input valves (temperatures in your case) appear in the input data table! simple as.

Have a play, if you cant work it out gimme a msg and i will send you an example.

change the file extension to .rss and have a looksies
this will work for a PT100 RTD and give you a value for your slc503 of 2000 for 200.0 degrees and 0 for 0 degrees.

thanks,

I will give it a try.

I downloaded and saved the zipped example file. When I tried to open it, it said invalid or corrupt.
Did I do something wrong?

rowens said:

I downloaded and saved the zipped example file. When I tried to open it, it said invalid or corrupt.
Did I do something wrong?

Click to expand...

I just tried the file and it opens fine. This is NOT a zip file, so it won't open with WinZip. Did you change the extension from .zip to .rss?



-Eric

I tried winunzip.
I looked at the ext on the file.
Do I need to import it into A/B first or just change the ext to .rss and open it?

AndrewB said:

change the file extension to .rss and have a looksies
this will work for a PT100 RTD and give you a value for your slc503 of 2000 for 200.0 degrees and 0 for 0 degrees.

Click to expand...

see post

The software that runs this board only accepts a limited number of file extensions, so when people attach files with extensions other than those allowed, a quick workaround is to simply change the extension to one that the board software accepts.

That's why AndrewB told you to change the file extension to .rss.

sorry.
I was looking and not reading I suppose.
It is bad when I overlook what is in front of me.
I tried again and changed the ext.Of course it worked.
It is amazing what happens when you follow directions.

thanks, again.

amazing

more importantly did you work it out?

I got most of it.
Please correct and or explain anything that I have misinterpreted. Critisizm is welcomed, good or bad.I am just learning this portion of programming.

The move instruction source -26588 got me.Why this number?Is it to zero the RTD on the first Scan? (S:1/15) The number being below the input minimum?
If I understand this instruction correctly it will put the number -26588 into destination register word O:1.0
That would be the word representing the first RTD output on the board.
I think the input from the RTD is word I:1.0 and that the reading after scaling of the information should go from 0-200.0 degrees.2000/10
From some other reading on some other threads of this site I think the input min 3957 and the input max 7770 comes from the characteristics of the RTD sensor.I read the thread about these numbers but lost it jumping around to related links.
The output N7:0 is the final destination of the information that can be used elsewhere for display or other purposes on say a touchscreen or to an output for a display.

Is this correct?

As far as it working out for me the panel is still in the beginning stages. I do not have the board here yet to actually test it.
I have the software(s),sensors and RTD's ETC and a touch screen on the way.
The machine is an R&D prototype model that we built using all mechanical relays and switches to verify it was a worthwile investment.
Now we(me) are to upgrade to a automated machine to put into production.
I do not have another machine here to even compare it to.
I certainly thank everyone who contributes to my understanding of PLCs.
The more I learn the more I know that I still need to learn.
If you can learn one thing a day it is a good day.

Without reading the manual, I will guess this. The only reason to send data to an input card is to configure the card. The move instruction is probably for setting configuration bits. Look in the manual for the card and find the section that refers to configuring the card. Often it is better to consider the number in unsigned hexidecimal format, it makes it easier to compare with the configuration bits referenced in the manual.

you got it in one

on the first scan i send a bit pattern to the card to set it up to do what i wanted it to do.

you will need the manual to tell you what it all means

Its appeared in decimal in your RSlogix.
I think you can change this??? never bothered myself.