Analog Input Readings via Profibus-Siemens S7

Hello Rott,

what I remember from my old project, I had defined I/O buffer, as type BYTE defined. I think this conversion can be very simple, I got this idea, I'll be prepare that temeratures as WORDs. Pls think about max values to not reach last bit on WORD, it can be reserved for sign in case of temp lower than 0. If this temp value can be, set that bit to 1 in your prepare WORD value, or check if it is there. This WORD temp value simply put to your buffer on needed offset f.ex.

DB20.DBB10:=MB10; //First buffer BYTE contain first BYTE of your WORD value

DB20.DBB11:=MB11; //Next buffer BYTE contain next BYTE of your WORD value

In this case BYTE order you can set as you prefer, don't forget use this criteria for back conversion. Via that sign bit you can know if it is positive or negative value. Helpful?

Update: this system can be used for Send criteria, but look to that BYTE order on RECV buffer for right conversion, probably temp values are send with this criteria. Probably now think that my recommendation cant be helpfull for RECV, but that conversion probably yes.

Update2: can you post some value of temperature and received value in buffer (with right order)? Better if it is possible also negative temp value example.