S7-300 Monitor I/O

Hi Everyone,

Very new to the Siemens world of PLC's and have little knowledge about S7. I have worked with some AB PLC's in the past but have gathered it is very different to Siemens! So have signed onto this forum to try get abit of much needed help and advice. Apologies in advance if some of my questions seem rather silly or simply, but i have on a very steep learning curve! I have a couple of S7 programming coarses booked for the coming months but want to get abit of knowledge first.

Anyway... I have got an S7-300 PLC rigged up to a small conveyor with a few sensors and actuators on. I am using a standard company FB which has many functions for different conveyors and specifications. But I basically want to override some variable I/O states, is there a function within S7 that I can online monitor and change the state of an input or output?

Cheers
Austin

P.S sorry for the long winded explanation...

To monitor memory adresses - merkers and DBs, you create a variable table, aka VAT. Activate the "glasses" to make the online status values display. Type in values in the "modify values" column, and hit the "lightning" button to transfer the modified valies to the PLC.

To force real i/o, activate the "Display force values". Similar to VATs, except there can only be one of these tables.
Here you can force inputs (make the program interpret the input state as the forced value irrespective of the physical inputs state) and force outputs (force the physical output irrespective of the program).