Here are two important tips that will help you establish communication with the PDX. After you have connected in terminal mode using X-ware, you will notice that you do not see a prompt ">" like some of the other x-ware products. This is normal. The PDX does not return a prompt at the terminal.
In order to verify your communication with PDX you need to know that the default address for the PDX is 8. Unlike some the other X products which default to 1, the PDX has three hardware address select inputs on the 25 pin connector which if left untouched result in a address of 8. In order to get a response from the unit you must precede the command with a valid device address. One of the best commands to help determine a devices address is the R command. Issuing 8R(be sure to use capital letters) should give you a response of *R, *S,*B , *C . If you do not see a response to this, the unit may have been set to a different address in which case you will need to try a different address with the R command, like 1R,2R, 3R until you receive a response.