RS5000 ascii problems

I have a machine running rs5000, and one of the functions is to send an ascii string to a laser scriber to mark a tag. It seems to run fine random amounts of time, and then it doesn't send the ascii information. The program has 3 rungs of AWT's, one is start transmission, then the string, then end transmission. When i check the ladder, the first AWT rung is true (STX) and the enable bit is lit, but never sends a done bit. Any ideas why?

Can you post your program?

I'm new here, don't know how to post the program in the forums, plus it's an obscenely large program.

This kind of begs the question about the STX not finishing but why don't you concatenate all of this into one string and send it as one unit?

bernie_carlton said:

This kind of begs the question about the STX not finishing but why don't you concatenate all of this into one string and send it as one unit?

Click to expand...

would I concatenate the string with $02 -string- $03? or do I need to actually have <STX> -string- <ETX>

It really depends on what your target is expecting. I was thinking you were sending 02h then the string then 03h but you know best what you are sending and what is expected.

If you are sending three AWTs then there are no appended characters.

If you have the string with just 02h and another with just 03h as well as the actual message string then two ACNs will concatenate them into a final combined string. Unless the end device requires some sort of time delay between the control characters and the message string then the single concatenated string would be easier to deal with as far as sending is concerned.

The knowledgebase has a lot of good examples as well as troubleshooting information.

I've tried it both ways, with the same result. It will run and send the string correctly for awhile, then it will just sit there and never turn on the done bit. The rung is very simple, just one bit that makes the rung true. I normally just pulse the bit for 1 second, but have tried latching the bit on until the done bit comes on but it doesn't make any difference. I don't know what would prevent the AWT instruction from working all of a sudden. The enable is lit, but no done bit.

Do you get the .EU (Queue) bit? Do you get a .ER (Error) bit?

I get .en, .eu, .rn all on, .er and .dn off

I really don't have anything else helpful, sorry.