slc 5/05 ascii awt and ard instructions

I'm having trouble writing to the processor. I followed Rockwell's knowledgebase #A16898 and the processor will write to the hyperterminal just fine but when I type "test" and hit the enter key on the hyperterminal I get no response. Wondering if I have the terminal or channel 0 set up properly. Where I am going with this is I eventually want to communicate to a loss of weight controller that doesn't understand hyperterminal, I have to use docklight scripting??? but I'm just trying to get some bi-directional communication at this time.

Thank you

Sheirj

If you followed the Application Note A16898 to the letter then you won't get a response on Hyperterminal. Additional programming would be required to echo the "test" back to hyperterminal. If you check data file ST12:3 it should contain the word "test" or any other four letter word that to send to the PLC through Hyperterminal.


This app note just scatches the surface of ASCII communication.

Greetings Sheirj,

and welcome to the forum ...

the program at the end of this post may demonstrate the techniques you're asking about ...

I doubt that the string-and-integer conversions will be of any use to you ... but the ASCII commands might be helpful ...

Thank you for responding. The problem I'm having is when I type test or any of the many other four letter words I've tried to send, I don't see them in st12:3. Am I using the hyperterminal correctly?

Thanks.

Thank you for welcomming me. I am new and don't have many resources to turn to.
You mentioned to look at the program at the end of the post. I don't see it? I clicked on "this post" in your message but I didn't see a program. This seems like a simple task. aarrg.
Thank you

sheirj,

The attached file at the end of Rons post is the program. Its labled
CH0Inout.zip

I see said the blind man!

This seems like a simple task

Click to expand...

ASCII communications with a PLC usually doesn't fall into the "simple" column ... but your comment brings up a story that I haven't thought about in years ...



a very frustrated young man came to me one day asking (actually begging) for help ... he had decided to learn PLCs "on his own" by studying the books ... he had started out by trying to work his way through the instruction set manual ! ALPHABETICALLY ! ... he had been frustrated for many weeks trying to get a grip on the ASCII instructions ...



I explained (as gently as I could) that he would have been much better off if he had started at the END of the list and worked his way forward ... at least he would have come to XIC and XIO in a reasonable amount of time ...



well ... back to your problem ... here’s a little trick that often helps me when I’m in the very first stages of working through something like this ... get a couple of LEDs from Radio Shack and wire them into your communication cable ... if you need me to, I can come up with a wiring diagram ...



but the main idea is that when one of the LEDs lights up, the computer/HyperTerminal is transmitting ... when the other LED lights up, the PLC is transmitting ...

you can get something of the same effect (at least from the PLC's end of the line) by monitoring the LED marked "RS232" on the front of the processor ...


sometimes it’s VERY helpful to know for sure that one thing is even TRYING to say something to the other one ...


so what’s your deadline on this project? ... and is it just for “fun and games” or for “I’m getting paid to do this” work? ... I’m pretty tied up right now, but I’ll help as much as I have time for ... the more details you give us about your setup, the more detailed help we can offer ...

Here's the story, I'll try to be brief.
I am a recently retrained aircraft mechanic that took the only job I got offered, my younger classmates are getting hired, after completing a two year automation course at at tech school. I am replacing a 13 year technician at a water plant and he there is alot of pressure on me to perform like him and he was good. Anyway, we, the company I work for in which I am the only employee, installed a loss of weight controller. Now the plant manager wants it to display total weight and clear that total at midnight. So I need the controller to communicate with the slc 5/05. I thought I would start by using hyperterminal. The manufacturer of the controller has been of little help in tunning the controller in the first place and have no help for me to accomplish this task. I do have the controller responding using what is called docklight scripting. I had to figure out the hex codes myself to send to the controller to get it to do what I want. Such as 3E532053540D200 is the code for start. I'm thinking of seeking professional help for my own sanity. Hope that helps you help me.
Thank you for your interest so far.
P.S. deadline is by late summer so I have some time.

Greetings sheirj,



the good news is that we’ve got time to work on this ... you’re on the right track by using HyperTerminal to test things out ... I’d suggest that you leave the SLC-5/05 out of the picture until you get everything at the controller end working with HyperTerminal ...



here’s a suggested plan of attack ...



write a step-by-step listing of what has to happen for a successful operation ... and then post that listing ... here’s an example off the top of my head ... and remember that I know absolutely NOTHING about your equipment except what you’ve told us ... specifically, I have ZERO experience with the weight controller you’re using ... with that in mind, the attempt at my description of your operation might be quite humorous ... it’s up to you to straighten it out ... basic idea: if you can’t adequately describe the process, then NOBODY can program it ...

(1) HyperTerminal sends code “

Click to expand...

3E532053540D200” to the controller ...



(2) controller starts recording loss of weight ...



(3) loss of weight value is displayed in pounds on controller’s display (question: does the controller even have a display - or will the SLC display the values on a PanelView, etc.?) ...



(4) the controller sends the current value to HyperTerminal in a four-digit HEX format ... for example:



ABCD = 100 pounds

119B = 200 pounds

81BD = 313 pounds

(note: these are all meaningless random values - but we’ll need some realistic values to test things as we go along ...


(5) the weight-lost value keeps increasing as material is used from the vessel ...



(6) the controller keeps updating HyperTerminal with the current value ...



(7) at midnight HyperTerminal sends code “BDE123AB” to tell the controller to reset the accumulated weight value back to zero ...

Click to expand...

try to write your listing something along those lines ... most programmer’s call this “pseudo-code” ... it’s sort of like a “flow-charting” step - but not near as much trouble to develop ... it doesn’t have to be fancy - but it DOES need to be precise ...



anyway ... once you’ve got the step-by-step procedure all nailed down, be SURE that you can make the puppet dance by typing the appropriate commands through HyperTerminal ... and make SURE that the controller will give you the expected response ... EACH time and EVERY time ...



during this part of the programming process, you (the programmer) are temporarily playing the part of the PLC ... so “be the PLC” as a famous forum member would say ...



once you’ve got all of the HyperTerminal-to-controller communications nailed down, then (and only then) will it be time to start working on the PLC end of things ... and ideally, you’ll be able to leave the controller out of the picture during that phase of the operation ... specifically, you’ll use HyperTerminal to play the controller’s part ...



when we’ve reached that stage, we’ll concentrate on writing the ASCII commands to make the SLC duplicate the same procedures that you’ve been doing manually ... and once HyperTerminal has confirmed that the SLC can (and does) say the right things - at the right times - then it’s time to start thinking about tying the two ends of the line together - and kissing the temporary go-between HyperTerminal goodbye ...



now obviously I’ve made a LOT of assumptions here (and gosh I hate that word) ... you need to correct these where I’ve been wrong - and confirm these where I’ve been right ... take your time and dot all of the “i’s” and cross all of the “t’s” ... this isn’t ONE big task ... actually it’s two much smaller tasks ... one is the controller end ... the other is the SLC end ... by using HyperTerminal, you can separate the job into bite-sized chunks ...

I'm thinking of seeking professional help for my own sanity.

Click to expand...

I’d hold off on that for at least a couple of weeks or so ... I think that you’ve got time to get this done ... and besides, sanity isn’t all that important anyway ... I hardly even miss mine anymore ...

Sorry I haven't responded lately, had to put out a few fires.
The controller is a Hardy instruments 2160. They tell me that they have never been able to communicate with it using hyperterminal. They use docklight scripting from www.docklight.de. That is how I got the controller working with the hex codes I typed into docklight. Sound strange? I haven't had any success getting hyperterminal to read from the plc yet either. I feel that that is one of the first steps I need to accomplish. I also don't understand how to send a hex code to the controller and how to recieve the hex code and translate that to a decimal value. I have a long way to go.
Any way here is my step by step
Write to controller 3E582053540D2004. This will make the controller send out the accumulated total.
Next, I need to clear accumulated total. To do this, I have to stop the controller, clear the total and restart the controller. These are the codes. Stop = 3E532053500D2004, Clear total = 3E532041540D2004 and start = 3E532053540D2004. Again these codes work using docklight. With docklight I can select hex format and type in these codes and the controller does what I want it to do. I don't understand how to do that with hyperterminal.
That's the deal.
Thanks again
Shierj

I'm thinking of seeking professional help for my own sanity.

Click to expand...

well, now it’s time to start calling in some reinforcements ... basic idea: if you can’t do it with HyperTerminal, then you’re probably not going to be able to program the SLC to do it either ...



sorry ... but there’s just not enough here for us to work with in an “over-the-forum” situation ... but then again, that’s just ME ... maybe someone else out there has some experience with this type of hardware? ...



just for discussion ... if I absolutely HAD to do this, I’d start out by rigging another computer to “eavesdrop” on the conversation between Docklight and the Hardy ... I’d be willing to bet that Docklight is adding a checksum (or something similar) to the basic command strings that you’re typing in ... once I had those checksum values, then I’d try to duplicate the transmission with HyperTerminal ...



what we know: Docklight is saying “SOMETHING” to the Hardy that makes the system work ...



what we don’t know: what is Docklight saying that HyperTerminal is not saying? ...



if we can find out exactly what that “SOMETHING” is, then we could almost certainly program the SLC to say the same thing ... monitoring the successful communication link is one way to figure out what’s going on behind the scenes ... I’ve used the technique before with other systems ... I’d be willing to bet substantially more than pocket change (but less than the rent) that the technique would work on your problem too ...



good luck ...