Problem reading MF using Modbus TCP

[andre.umbul]

I have a v130-330R34 (A). I've been trying to setup the Modbus TCP slave function of it using a Kepware OPC server as the master. For most part it works (MB, MI and ML). However I've been having issues retrieving the MF data. The two registers I need to grab are MF12 and MF13.

I've following the manual by using the following calculation to get my modbus addresses (16384 + 400001 + 12*2 = 416409 and 16384 + 400001 + 13*2 = 416411). 16384 being a decimal representation of 4000h . I think i've pretty much tried every single permutation and still can't get it working (offset of 1 per index instead of 2). I've also tried swapping the high and low bytes in the PLC using the struct and swapbytes function and I still don't have any luck.

Any one can provide any assistance?

Andre

[Ofir]

Hi Andre,

If I'm not wrong the calculation should be as follows:

MF12 - 400001 + 16384 (4000h) + 12 = 416397

MF13 - 400001 + 16384 (4000h) + 13 = 416398

Make sure you are reading 32bit register.

[andre.umbul]

Thanks for your help. It looks like my Kepware OPC server does not support 32 bit registers. Are there easy way to split an mf into two separate 16 bit registers?

Andre

[Gabriel Franco]

STRUCT FB allows it

[Ofir]

Hi Andre,

You can try reading the address in length of 2 (32bit register = 2 x 16bit register).

Anyway if you wish to split MF to 2 MIs you can use the function "Copy Memory". (Vector menu -->Use Offset --> Copy memory)