Chapter 4. Troubleshooting and Diagnostics
ASM-20
Installation and Operation Manual
4-6 Communication Link Tests 11/4/99 12:34
3. If Step 2 indicates a fault, and if the modem test described Modem Self
Test on page 4-4 was positive for both the local and remote modems,
the line circuits are not operating properly.
RCVR
RCVR
LOCAL
DATA
TERMINAL
XMTR
XMTR
LOCAL ASM-20
REMOTE ASM-20
DATA
DATA
CLK
CLK
REMOTE
DATA
TERMINAL
REM
Pressed
Figure 4-4 Remote ASM-20 in Digital Loopback
Local Digital
Loopback
This test is activated by pressing the DIG push button. It loops the received
data back to the remote ASM-20. (This test is equivalent to activating the
remote loopback from the remote ASM-20 - see Figure 4-5). The operator at
the remote end can determine the performance of the local and remote
ASM-20 units, and the lines between them.
Note
The modem with the pressed DIG push button must be in RCV or ASY mode
RCVR
RCVR
DIG
Pressed
LOCAL
DATA
TERMINAL
XMTR
XMTR
LOCAL ASM-20
REMOTE ASM-20
DATA
DATA
CLK
CLK
REMOTE
DATA
TERMINAL
Figure 4-5 Local ASM-20 in Digital Loopback
