Raymar 14.4 Installation, Operation & Diagnostics - page 20
0049-0300-XXX MIU/Power Port Series – USER GUIDE
08/04/2010
Rev. A
Page 16 of 26
&T2 NO FUNCTION
&T3 PERFORM LOCAL DIGITAL LOOPBACK (See Figure 3)
The modem must be in the command state with connection established when this command is
issued, otherwise an ERROR result code occurs.
The AT&T3 command establishes a loopback of received data, after demodulation, and sends it
back to the distant end. The modem is configured for local digital loopback, DSR is turned off (if
&S1 is in effect), the test timer is started with the value in S18, and an OK result code is sent to the
DTE. If S18 contains a 0, the test must be terminated by a &T0, H0, or Z command. The latter
two result in the modem going on hook. If S18 does not contain 0, the test is terminated after the
number of seconds stored in S18.
RESULT CODE
DESCRIPTION
OK
After 2 second delay
ERROR
If any other self test is active (&T1, &T6, &T7 or &T8) or if in idle state.
When
test
is
terminated.
&T4 GRANT REMOTE DIGITAL LOOPBACK (RDL) REQUESTS
When in the on-line state, the modem will honor a remote digital loopback request from a distant
modem if it occurs. This will result in an ERROR if the command is given while any V.54 test is
active (&T1, &T3, &T6, &T7 or &T8).
NOTE: There are data patterns that may cause a Remote Digital Loopback conditions. Care
should be given to the type of data being received so that no RDL modes will be initiated.
&T5 DENY RDL REQUESTS
The modem will not respond to a remote digital loopback request from a distant modem. This will
result in an error if the command is given while any V.54 test is active (&T1, &T3, &T6, &T7 or
&T8).