I am connected to a Siemens S7-300 series PLC. Tag browsing is not supported on the Siemens product. Is there a way to bulk import all of the tags if I do not know their addresses? I created a tag called [PLC]IB0 and I do get a value back so I know I can communicate and get values. I just need a way to create several tags at once and maybe from viewing the values of the tags I can figure out which ones are of value to me.
Thanks
In short, no.
More detailed:
Depending on your CPU, there may be 8k bytes inputs, 8k byte output, 8k byte flags and up to 4096 datablocks with 64k byte. Each of this may contain data as byte, word, double word, integer, float...
So, guessing addresses is not really an option 
It would be easier to inspect the plc program online with the Siemens programming software. Even without comments or symbols this should give you some hints. Id you don't have the option to buy the software from Siemens, you may use the free demo version.