Help comunication calculateur,automate et un PC

Hello,
I am an engineering student, now I am in an industrial project graduation
I want to make a statement of dosing (manufacturer Hasler and SCHENCK) with a supervisor who can view alarms and failures dispensers, to archive it in a database.
Solution 1 /
-a computer (PLC) the manufacturer of dosing Hasler communicates:
PROFIBUS or MODBUS Ethernet or DeviceNet
PLC put it as slave SIEMENS kind (you can use PROFIBUS)
-I want to communicate with a PLC SIEMENS PC to access the data transfer by the master is the computer (PLC) Hasler
Solution 2 /
Hasler-communicate directly with a PC computer that communicates PROFIBUS or MODBUS Ethernet or DeviceNet Rolling Eyes I do not know there is this possibility

I've never make a call like this
I do not know how the data is transferred by the Hasler computer (how the controller or PC knows addresses these parameters and data)
-if I was able to understand how I can change the address settings and data transferred from the master to the slave computer Hasler PLC siemens I can continue the work.
Is someone please explain to me how is the communication
and thank you in advance Smile