Micrologix 1500 Serial - Data read but not shown

[donl517]

I am using a Micrologix 1500 ARD instruction, It says it read in 56 characters but they are not being displayed in the ST register where they are supposed to be. Is there another way to find this data? Any suggestions on why it is not in the register?

TIA,
Don

 

[TimWilborne]

Is the ARD completing? What do you have for your string length? How did you get your string length? Does the ARD show an error?

 

[donl517]

No Errors. The String is coming from a data logger and can very in length. I would assume it is completing since it read 56 characters, but I will try latching the R6 and see.

Thanks,
Don

 

[TimWilborne]

Read the charactors in buffer first. ACB

 

[geniusintraining]

Don,


This is how mine are done, like TW said...also how many times are you using your control R-file,

 

[donl517]

Well I have verified that good data is being sent to the PLC but I am still not seeing it put in the ST register. My program is attached.

Thanks,
Don

 

[donl517]

Rungs 23-26 are where the ASCII Data is.

 

[geniusintraining]

Don,

The only thing I saw that might cause it...you put B3:4/0 infront of it...I thought that B3:5/3 might over write it...but no, maybe someone else will take a look

 

[donl517]

It could be that this would overwrite it, I could deal with that, but I am not getting anything, If it was being overwritten there would be something there, so what is overwriting it? It is perplexing to say the least. I have tried several variations of this program. I'm just hoping someone has the silver bullet!

Thanks Anyway,
Don

 

[donl517]

I wound up putting a one shot (ONS) on the rung that was coping ST20:0 to ST20:10 and then clearing ST20:0. Apparently the rung was staying true long enough to overwrite itself. I would not have thought that possible but that is what was happening. Thanks for all the help.

Don

 

[geniusintraining]

Thanks for the update and glad to see you got it.


Nice job