FX3U Analog Output Problem

[N-Automation 0]

Hi, first of all, sorry for my bad english... i started my first project with mitsubishi FX3U PLC at the moment, after reading many PDFs i am done with most of the things like reading analog values, setup analog inputs, pid and a wrote my own pid step controller for a solid state heating register... for the moment i ran into 1 main problem, and some minor questions... my main problem: i have 2 analog outputs, i need to have them 0-10V like they come from factory (FX2N-2DA). so far, so good... what i found is that i need to write my value for the output into bfm#16 (Bit0-Bit7) and then i need to set Bit1 of bfm#17 to start the output? first problem: my data is a word (16bits) and i limit the value to max 4000 via limitation_e block. how do i get this 16bit data into these 8bit? for you to know: i created a function block for my analog output, my value for this output is a word input of this function block. my minor questions: where is the main difference between a file register and a latched data register? i didnt find an explanation for this in my german documentation...

[Bryll 31]

I think the attached picture from the programming manual can describe Data and File registers better than I can with my poor English. Attached also a function block I made for the FX2N-AD for a project. Just unzip the file and import it. Hope it helps DataReg_FileReg.bmp FX2NDA_Output.zip

[M1923 0]

Latched data register is the register backup by battery or big electric capacitor after power failure. File registers will be backup by program memory, you can choose to backup the file registers or not by using command BMOV when their value have been changed. I think this the biggest difference. Hope this help.

[N-Automation 0]

Thank you very much, i didnt know that there are these functions (WR3A) i searched for them in the included documentation, but there is nothing... i finaly found now a documentation in german to this function...

[N-Automation 0]

i still didnt get the difference between data and file registers... if i take a look on the page you posted there is written: Data Registers fixed latched (battery backup) D512-D7999 File Registers latched (battery backup) D1000-D7999 for me as a green horn it looks like they are using the same memory area, and both are battery backuped... is there any difference in handling of these registers? i know that i can do something like this with data registers : ADD K10 , K20 ->Result= D514 can i do the same with file registers? like: ADD K10, K20 -> Result = D6549 ??? mybe i am to stupid for this, or i have done to much siemens... ;) sorry

[kaare_t 155]

No difference in handling these. Normally you use D1000+ normally, but you can use an EEPROM and use D1000+ as EEPROM written values by using a BMOV instruction into these. However, during normal operation there's no need to worry about D1000+ (and the expression "File Registers" are actually misleading).

[N-Automation 0]

ok... good to know, thank you