S7-sfc51 [rdsysst]

Hi all,

in these days I'm learning how to use the diagnostic management function SFC51.

I started with a simple SZL_ID data input as W#16#0019 (request the status led of all unit).

Now I read the description of the function with the help on line and read the Siemens manual concerning the SFC51 also, but I'm facing some problems with the use of the DR data output of the SFC51.
My question is, how to define the lenght of the data in the DR parameter??
In the image attached, I used 240 bytes just only for test.......
And how understand the result of the values write in the data area assigned to the DR???

Thanks in advance

Sorry..........
problem solved now.

Depending what system info you require, you'll find life's a lot easier if you use FB125 or it's little brother FC125 (for Profibus systems - I believe you need FB126 for Profinet).