User`s guide

TECHNICAL REFERENCE
72
&Tn Begins test modes
&T0 Ends testing
&T1 Analog Loopback
&T2 Reserved
&T3 Local Digital Loopback
&T4 Enables Remote Digital
Loopback
&T5 Prohibits Remote Digital
Loopback
&T6 Initiates Remote Digital
Loopback
&T7 Remote Digital with self-test and
error detector
&T8 Analog Loopback with self-test
and error detector