Hello capraloris;
The detailed explanation of the HART interface with your module is explained in chapter 4 of the following manual:
http://support.automation.siemens.com/WW/view/en/1096709

HART uses "commands" to request specific data from the HART slave modules. The master in this communication will be the 331-7TB00 module, and you must setup a HART "Command 3" to request "up to 4 measured values" from the HART slave. The "measuring interface" of the 331-7TB00 can be either 0-20 mA/ 4-20 mA or HART, so you cannot at the same time read the analog signal from the HART slave and request a second value over HART. You must read multiple values over HART, and that involves a Command 3.
You will have first to parametrize the HART slave, using a handheld HART communicator, or Siemens' PDM software (it will use the Profibus link to connect to the 331-7TB00 module), so that it recognizes its HART address and the values to be sent to the master.
Then it is a matter of using the Profibus interface (the 331-7TB00 can only work as part of an ET 200M station, with a IM 153-2) to connect to the 331-7TB00 module, write a Command 3 request to the HART slave, and collect the reply form the HART slave. This can involve using read records, as explained in the chapter I suggested.
Although the setup can look complicated, please take the time to study the interface as presented in the manual. Things should become clearer as your reading takes hold.
If you are curious about the HART interface, or if you need more complete information on HART, you could look at the opening chapters of the following document:
http://support.automation.siemens.com/WW/view/en/22063748
Hope this helps,
Daniel Chartier