FX3 Extension Registers

[Sergei Troizky 26]

I used to be a long time user of FX0/1/2 but never worked with FX3. Recently, I was reading a FX3U program and discovered a new type of device- extension register R. The manual says it can be used the same way as D register, in 16- and 32-bit operations. Here comes the question: what are the extension registers intended for? Is there a case they MUST be used instead of D registers? Edited 12 Feb 2013 by Sergei Troizky

[Crossbow 295]

They are just like D, more data storage. You don't have to use them, but they are handy for data logging, since there are 32,768 of them.

[Inntele 60]

Sergey, these registers can be used for the simple data storage, the same as D-registers, but they are especially useful for the creating of moving archives. But, if you want to output their values onto HMI screen, you can not do it directly. For this purpose you have to copy values of the appropriate R-registers to the group of D-registers with fixed addresses.

[kaare_t 155]

In addition, and very important: If you want to permanently store data from FileRegisters, you can store them in an EEPROM if you use one (just remember the EEPROM has a 10000 write limit so you can't write to it all the time, but e.g. if you have initial settings you can change them in the HMI and then press a "Save" button or similar and the File Registers can be loaded again during startup even if both the power and battery is gone...)

[Crossbow 295]

kaare_t, that was FX2N. FX3U has R addresses built in, and doesn't use EEPROMs.

[kaare_t 155]

Crossbow, you are correct in one way. However when installing the EEPROM in the FX3U you get access to the "parallell" area ER (Extended Filergisters). I have used this once for a customer that required the battery to be removed (offshore customer) before installation. By using an EEPROM the program is of course stored in the EEPROM, however by using ER you can store parameter values or any other value in the EEPROM memory using the special ER commands. By writing to the EEPROM values are retained even if the battery runs low (or is removed) and the power is switched off.

[Crossbow 295]

Yes, ER memory does exist in FX3U. But as I stated, R registers are NOT stored to the memory module. The discussion was about R registers. And it's Flash ROM now, not EEPROM.

[kaare_t 155]

Correct, as it should be...

[Bryll 31]

I have to wake this old thread up, since my questions are about the R-registers. The setup is a FX3U connected to a Beijer E1101 panel. I found the R-registers quite handy for data storage since they are battery backed. Wrote a small FB that traces certain events and logs a time stamp and current login level in the panel. There's no problem to show these registers in the Beijer panel, so I don't have to use any D-registers. But it seems that some of the data is lost during a PLC reboot. Will check the code again, but I'm almost sure it is as it should. Anyone else discovered data loss in the R-registers after a reboot ?

[Inntele 60]

Hi Bryll, What do you mean under 'reboot'? If just a power-off to power-on, then never were lost. And I used a full range of R-registers in the machine.

[Nightfly 12]

We also used the whole 32K of R registers in the FX3U (to hold recipe information sent from a PC). Never once lost any info and we have a hundred or so installations worldwide. Think it's a bit different on the 3G though - fairy sure we needed an extra battery to hold up the R registers (we don't use 3G much so I could be wrong)

[Bryll 31]

Thanks for your answers, have to find the "bug" then