
Appendix A. AT Commands and 
maximum length for a command line is 40 characters. Each com- mand line is executed by the Express XRT upon receipt of a termi- nating character. The default terminating character is a carriage return (ASCII 013), but it can be changed by writing a different value to register S3. Before the terminating character is transmit- ted, the command line can be edited by using the backspace char- acter (ASCII 008) to erase errors so the proper commands can be entered.
Using an AT Command
Type AT followed by the letter of the command and numeric val- ue of the setting desired and then press Enter. The following com- mand returns the software version of the unit:
ATI1
Using S-Registers 
The configuration of the Express XRT can be changed or reviewed with 
Reading an S-Register 
Type ATS followed by the number of the 
ATS0?
Reading an S-Register  String
The Express XRT uses 
ATSS80?
Changing an S-Register 
Type ATS followed by the number of the 
ATS0=2
58  | Express XRT User Guide  |