Hello mulenga;

If a module reserves addresses 0-1 in the hardware configuration, I would expect it to be a digital input or output module. The hardware configuration will show the reserved addresses 0-1 either in the I-address ir the Q-address column, which will tell you if this is DI (input) or DO (output) module.

These eeserved addresses are hown as byte addresses, but the  DI/DO modules are bit-oriented, in your program you must access each of the 16 bits of that module individually. Therefore you should search in your program for bit addresses I0.0, I0.1, I0.2...I0.7, I1.0, I1.11.2...I1.7 for an input module, or Q0.0, Q0.1, Q0.2...Q0.7, Q1.0, Q1.1, Q1.2...Q1.7, for a DO module.

As Piscean asked you before, is this an uploaded program from an existing PLC? In that case you will have no symbols  no comments in yhe uploaded project  since these were never dowloaded to the PLC in the first place. Your best bet would be to try to re-create a symbol table, based on electrical diagrams (or any other engineering design document) of the machine or process this PLC is controlling, if you can get your hands on them.

Hope this gelos,

Daniel Chartier