s7-1200 plc

Hello,
I need to connect my plc (simatic s7-1200) to the computer via ethernet connection, i set may LAN IP adress to: 192.168.56.101 but no communication occured between it !. i've changed the last no. around 100 but still no communication !.
please help me to for this problem and advice me if there is a standard IP adress for such plc ?.. waiting for kind help

sometimes the subnet can cause a problem. try auto detect bby going to online & diagnostic, accessible devices, search. if you find it connect to it, it will ask for additional address for laptop, yes, then if you succeded check for plc address.

First some obvious things:
Are the PLC and Computer connected to the same network via a switch/hub or are you connecting directly with a cable between the PLC and Computer.

If they are on the same network or directly connected then do some basic diagnostics checks.

What IP address and what Subnet range is the PLC set for, have you set it to use a Router. Write down the values and post them here.

What IP address and what Subnet is your computer set to use. If you don't know then run a Command Prompt (All Programs/Accessories/Command Prompt) and type ipconfig and press return. Note the IP address and Subnet range for the wired ethernet connection. Post them here. If you find that there is also a wireless connection then disable it. The method varies depending on the driver and system.

Let us know the results.

Dears Balash & BryanG,
I'm connecting directly with a cable between the PLC and PC,
also, i've applied your advice ( online & diagnostic, accessible devices, search) successfuly which help the computer to find the three PLCs and the HMI panel !.
The software has update files for the three PLCs and the HMI panel , it loaded successfuly to the PLCs, but not loaded to HMI panel!..I dont know why the update files is not loaded to the HMI ?!..if you can help !..thank you

HMI tend to need for downloading all data including system config and all screens if you do not have original program, cause you cannot upload files from HMI, you can just access online diagnostic

I don't use the Siemens HMIs so can't help much with that. Glad you managed to get things to work with the PLCs.

Hello again,
I need to download an updated project to the 3 PLCs to make HMI panel functioning correctly, please advice me how to delete the old project from the PLCs to download the new one?.. waiting for kind help..

if you use 1200 i think that by going to download all (software and system configuration) would do the trick.
if updates are only to program blocks, you could either download all or modified software blocks, or delete them first from PLC and then download them to remove unused blocks.
if however you only had changes in system config due to new HMI then you could just download new system config
all this is done under online -> download
beware that you must be online to do this.

Thanks for kind help.. I've applied your advice and all plc's and hmi panel has rec ipe the sofware correctly.. thank you again..