Enabling AT Commands on the DSU III AR
LOADING DEFAULT SETTINGS:
Enter the Manual Command 8A, Value 00 to Load Factory Option Set #1.
Use UP ARROW to delete current entry
Enter "8", "SHIFT", "A", "ENTER" to complete the Command entry
Press ENTER when VALUE:00 is displayed
This change is almost instantaneous. Next, connect a straight through serial cable to the COM port on your PC to the Aux port on the DSU. Now we need to configure the DSU for AT commands.
SETTING DSU FOR AT COMMMANDS VIA AUX PORT:
Set the AUX port rate for 1.2k.
Use option 1=1.2K AT CMD under
B) AUXILARY PORT
That is the only rate that the DSU's were designed to work with, for AT commands over the auxiliary port.
DISABLE DTE COMMANDS:
Also, option 4= DTE CMD OPTION under
needs to be set to 1= DISABLED. That command is for using AT commands over the primary DTE interface.
Now we open a Hyper Terminal Session.
HYPER TERM SETTINGS:
1.2k - bits per second
8 - data bits
None - parity
1 - stop bit
None - flow control
Next, we will issue the escape sequence to issue AT commands.
GETTING THE DSU READY FOR COMMANDS:
type "+++" then hit <enter>
now type "ATE1" then hit <enter>
Do not be alarmed when you do not see your characters show up on screen.
You should see "OK" - now your characters will show up onscreen.
Lock the front panel
AT_P0 disables the front panel
AT_P1 will enable it
When you reset the unit, these changes go away. To write these changes to memory add the suffix "&W"
So - AT_P0&W will make the change permanent, until you come back in command mode and enter AT_P1&W.
Other AT commands are listed in the Appendix of the manual.