9
CHAPTER 3: Configuration
3.2 DCE/DTE Switch Settings
Correct setting of the DCE/DTE switches eliminates the need for RS-232 crossover
cables. If the RS-232 device you are connecting to the Modem is a PC, terminal, or
host (or is wired like one), set both of the DCE/DTE switches to DCE. If the RS-
232 device you are connecting to the Async Short-Haul Modem MP is a modem or
multiplexor, or is wired like one, set both of the DCE/DTE switches to DTE.
3.3 Special Configuration
If your Modem requires special configuration, use Table 3-1 as a guide. This table
shows all of the possible Modem switch settings. Following the table are brief
descriptions of the Control Input, Control Output, +Voltage Output and Carrier
Controlled by (Cin) parameters shown in the table.
Table 3-1. All possible switch settings for the Modem
Control
Control
+Voltage
Carrier
Switch Settings
Mode
Input
Output
Output Controlled
(DCE/DTE)
(CIn)
(COut)
(VOut)
by (CIn)
1
2
3
4
5
6
7
DCE
4
8
6
Disabled
ON
ON
ON
OFF
OFF
OFF
OFF
DCE
4
8
6
Enabled
ON
ON
ON
OFF
OFF
OFF
ON
DCE
4,11,20*
8
6
Disabled
OFF
ON
ON
ON
OFF
OFF
OFF
DCE
4,11,20*
8
6
Enabled
OFF
ON
ON
ON
OFF
OFF
ON
DCE
4
6
8
Disabled
ON
OFF
OFF
OFF
ON
ON
OFF
DCE
4
6
8
Enabled
ON
OFF
OFF
OFF
ON
ON
ON
DCE
4,11,20*
6
8
Disabled
OFF
OFF
OFF
ON
ON
ON
OFF
DCE
4,11,20*
6
8
Enabled
OFF
OFF
OFF
ON
ON
ON
ON
DTE
8
4
11,20**
Disabled
ON
ON
ON
OFF
OFF
OFF
OFF
DTE
8
4
11,20**
Enabled
ON
ON
ON
OFF
OFF
OFF
ON
DTE
5,6,8*
4
11,20**
Disabled
OFF
ON
ON
ON
OFF
OFF
OFF
DTE
5,6,8*
4
11,20**
Enabled
OFF
ON
ON
ON
OFF
OFF
ON
DTE
8
11,20**
4
Disabled
ON
OFF
OFF
OFF
ON
ON
OFF
DTE
8
11,20**
4
Enabled
ON
OFF
OFF
OFF
ON
ON
ON
DTE
5,6,8*
11,20**
4
Disabled
OFF
OFF
OFF
ON
ON
ON
OFF
DTE
5,6,8*
11,20**
4
Enabled
OFF
OFF
OFF
ON
ON
ON
ON
*Multiple input pins are "or-tied"—if any input goes low, carrier is dropped.
**Multiple output pins generate the same signal simultaneously.
