Extending memory

[WKla]

Hi. I use GX IEC Developer and FX1N. I want to log some data in the memory. It is possible that the internal memory will not be enough. Could you tell me please if there are some memory cassettes I can use in this purpose? Thank you.

[Gambit]

You can't create more devices in the FX1N by using a Memory Casette. For the FX2N there is a secret instruction (DOPT) which you can use to read & write Dataregisters to extended dataregisters. This way you can increase the amount of Dataregsiters with 15000. I do not know if this also works for the FX1N.

[Crossbow]

In the FX1N, you can reserve file registers in blocks (each block takes up 500 steps of program memory, but gives you 500 registers). This is done in the PLC Parameters. So you can have the 8000 built in registers and use some of the extra program memory to create up to 7000 file registers. In the FX3U, you get 8000 data registers and 32768 file registers.

[WKla]

Could you please give me an example of using DOPT instruction, because I didn't found it in the manual. Thank you.

[Gambit]

It's not in the manual. This is the special instruction but unfortunately it's only for FX2N. dopt.pdf Edited March 2, 2007 by Gambit