SLC5/03 Input Buffer Chan 0

[Big John T]

Now get this I just plugged it into my partners computer and it works fine! Now I got to figure out which of the three things I did inbtween...

Thanks for all the support and help...

John

 

[Big John T]

Now I need a drink.

Is the SLC chassis grounded ? Are you using a USB/RS232 converter between the computer and the SLC ? Is your shop located on top of an ancient burial ground ?

No, Yes a 1747-UIC, Maybe

It works fine on one computer and halfway works on another computer refuses to work on this compute and two others...

John

 

[Big John T]

Ken, I can't thank you enough for sticking with me and helping. Today will be a better day for sure... And when this project is done I'm going fishing!

John

 

[geniusintraining]

I had a few days off but glad to see you got it , nice job!

 

[Big John T]

I need a few days off now...

This morning I have written and tested my code all ready. I've been beating my head on this one for over two weeks for what should have taken less than a day...

Thanks for your help and everyone else who pitched in...

I'm making that serial break out box that Ron suggested for the future...

John

 

[Ken Roach]

So, you plugged the SLC into another PC and were able to receive and transmit ASCII data successfully between the SLC and Hypterterminal.

Does this mean you also got the servo / SLC application working correctly ? Did you change something in the strings, or something in the wiring ?

 

[Big John T]

I had to change my string a bit. I'm almost ready to plug the servo drives in. I'm testing with hyperterminal on another computer. Hyperterminal on mine would only show garbage, My old one would not send the "ok" from hyperterminal. The old laptop did neither. The funny thing is the two new desktops are identical. Mine hyperterminal is hosed and my partners is fine. I went with adding ^M and using AWT. Seems to work fine. One last bit of code to get working and I'm there...

Thanks
John

 

[Big John T]

I have sucessfully written to and received a response do both drives... Today will be a good day... Tomorrow I will shoot this computer LOL...

John

 

[Big John T]

Check this out. During testing we put values in the velocity box of the drive software and the tag was RPM... So all the time I assume I need to send an RPM number to the drive. Well after all the other problems I had working out the communications or lack of and hammering out my code then testing it in hyperterminal... I hook up to the drive with my PLC and sucessfully send and receive ASCII back and forth iniated from the PV... So finally all is working great.

Now I press the big red run sequence 1 button and look at the drives... Nothing... pulling more hair out... I disconnect from the drive with the PLC and hook up the drive programming software... dig around a while... open up the drive control panel... green lights all seems normal... but no movement. I look back at the control panel and the count has changed... The COUNT CHANGED!!! WTF!!! how could the count change the servo is not moving... So I watch closely and the count is going up but real slow. I look closely at the servo and sure enough it is going but like 5 counts a second or so slow you really have to look at it to see it move... More head scratching and digging in the drive software...

I Open up another copy of the software on my compter...Start a simulation session... When I put a register number in the velocity box it changes from RPM to 0.1 counts/second!!! After a quick chat with tech support I find out "Oh your using registers, yea it changes when you use registers"

Ok back to the drawing board on sending that number to the drives as 3000 RPM is 3,640,000,000. Now convert that to a string!!! As you can only convert intgers to strings in RSLogix I had to break out the number by billions, millions, thousands, and hundreds... Then make sure I had all the zeros in there where they belong... To make a long story even longer I finished up about 9pm last night. I only have one bug to sort out this morning... I'll post the finished code if anyone is interested...

A BIG THANKS to all those that helped me...

When you don't get what you expect you get experiance!

John

 

[Big John T]

Well I know a lot more about what I didn't know about float numbers now... I have to store a string with a max value of 3,618,000,000. I arrive at that number by multipling RPM x 1,206,000 and store it in a float... I have been using a divide by then subract .4999 but it does not work with all numbers... Well more to learn...

John

 

[Big John T]

Well that didn't work so I gave up.

This however does work for me.

I found the smallest multiplier then did some excel work to find the formulas needed and a couple of CPT's later here we are.

Thanks
John

 

[geniusintraining]

John,

In some controllers you can do the math after you send the string to it... (not sure about yours)

You would send (say) 3,618 when you get the string in the servo controller then multiply in the controller program then place it in the controllr register for position

Just a thought

 

[Big John T]

No scaling in the servo controller. But I finally got it to work as needed...

Attached is the file if any one wants to see it...

I ended up having to create a string and one value had two different multipliers... The trick was to add the leading zeros on the hundreds when that part was less than 100 and to plug in three zeros when the hundreds was 0..

Thanks for all the help. I'm relaxing and having a beer...

John

 

[Big John T]

We finally figured out what the communications problem was. Get this. When we communicated with the controllers with the control programming software it changed the communications speed of the drives to 19200... On power up the communication speed defauts to 9600! Our hyperterminal and the SLC was set at the recommended speed of 9600...


Thanks

John