mick1994

Mitsubishi fx5u SFRD instruction

2 posts in this topic

Dear sir, 

Good day. I using SFRD instruction to read all the value stored when the sensor trigger. When the SFRD instruction is end(whe the word device number goes to 0), it will move the value to my store value and change my store value. 

May I know how to stop it to overwrite my store value? 

 

Share this post


Link to post
Share on other sites

Hi mick,

i think your problem is the shift that takes place after every read from the FIFO buffer, see section "processing details" for the SFRD instruction
at page 352 from the "MELSEC iQ-F FX5 SeriesProgramming Manual[Instructions, Standard Functions/Function Block" manual
https://www.atronika.com/Mitsubishi/PLC/MITSUBISHI_manual_plc_fx5_programming.pdf

Maybe you can use the "POP" instruction instead, or you can read the data using an index-register ("Z")

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!


Register a new account

Sign in

Already have an account? Sign in here.


Sign In Now