Logix 5000 FLL instruction

[Saint AAI]

EDIT: Meant FFL not FLL.

Hi, I'm struggling to get this instruction to work and I don't know why. I've created an array and a control word and am trying to load my source into the array, but when I try to compile the code it says that my Source is not a valid type? Yet the source is just a DINT which should be valid. Any suggestions on what I've done wrong or do people need more info?
Thanks, Shane.

 

[robertmee]

Hi, I'm struggling to get this instruction to work and I don't know why. I've created an array and a control word and am trying to load my source into the array, but when I try to compile the code it says that my Source is not a valid type? Yet the source is just a DINT which should be valid. Any suggestions on what I've done wrong or do people need more info?
Thanks, Shane.

FLL doesn't use a control word. Are you sure you didn't mistype a FFL (FIFO Load) which does use a control word?

 

[Saint AAI]

Sorry, I meant FFL instruction. Typo.


Anyway, I've figured out what I've done wrong. My array was the wrong data type. I put it in as what ever the logix software came up with as default when I clicked on the tag name and selected new. Deleted that and made a new one which was a DINT[3] (only 3 layers to my array) and its accepted it. Haven't tested it to see if it works yet though.
Thanks, Shane.

 

[robertmee]

So, to be sure, you are trying to use the FIFO Load instruction and not a File Fill instruction. If you want to fill an array with a single value, you should be using the File Fill instruction (FLL). If you are trying to a file load/shift then use the FIFO.

On the FIFO, I believe the Source and FIFO MUST be the same data type. A File Fill instruction you can mix data types, but the FIFO I believe they must be the same. Is your FIFO array also a DINT? Also, the FIFO should be the first element, not the entire array, so it should be something like MyDINTtag[0], not MyDINTtag.

If you can post a snapshot of the offending rung, and maybe a properties box on the tags involved, that might help.

 

[Saint AAI]

Yes it is the FIFO Load instruction I am using. It didn't work as my array was a different data type to my Source. Works fine now, thanks.