10
ASYNC FIBER OPTIC MINI MODEM
Table 3-1. Strap/Switch Selection.
Strap Identity
Function
Position
Factory Setting
CARR
Selects Carrier
On (ON)
ON
constantly ON
controlled (CL)
controlled by RTS
DLY
Selects RTS/CTS
2 msec
2 msec
delay
15 msec
DCE/DTE
Selects DCE or DTE
DTE
Switch
DCE
DCE
3. The Modem is factory-set for DCE. For DTE
operation, move the switch to the DTE position
(see
Figure 3-2
).
Figure 3-2. DTE/DCE Switch Operation.
TD
RD
RTS
CTS
DSR
DCD
DTR
2
3
4
5
6
8
20
DI
DO
RTS
+V
CD
N.C.
DCE Position
D
300 ohm
TD
RD
RTS
CTS
DSR
DCD
DTR
2
3
4
5
6
8
20
DI
DO
CD
+V
DTE Position
300 ohm
N.C.
N.C.
N.C.
