Posted 20 Aug 2020 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
Posted 20 Aug 2020 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" manualhttps://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