3.2 SETTING THE ACTIVE/PASSIVE SWITCH
The active/passive switch is used to control the mode of the
receiver; it has no control over the transmitter since the transmitter is
fixed in the active mode.
To configure your Model 2017A receiver, you first need to deter-
mine whether your device will be active or passive. If you are going to
use the Model 2017A receiver to source current for the loop, set the
switch to the “active” position. If the Model 2017A is to be used in an
active loop, set the Model 2017A receiver’s active/passive switch to
passive.
WARNING: Never connect two active devices together. Your
configuration must be "active to passive" or "passive to active".
3.0 CONFIGURAT I O N
The Model 2017A is easy to use. The only configuration neces-
sary for operation is the proper setting of two switches: the external
DCE/DTE switch and the internal active/passive switch.
3.1 SETTING THE DCE/DTE SWITCH
Figure 1 shows the location of the DCE/DTE switch on the PC
board, as well as the location of the terminal block and surge suppres-
sors.
For your convenience, the Model 2017A has an externally acces-
sible DCE/DTE switch (see figure 2). If the RS-232 device connected
to the Model 2017A is a modem or multiplexer (or is wired like one),
set the switch to "DTE". This setting causes the Model 2017A to
behave like Data Terminal Equipment, transmitting data on RS-232 pin
2 and receiving data on pin 3.
If the RS-232 device connected to the Model 2017A is a PC, ter-
minal or host computer (or is wired like one), set the switch to "DCE".
This setting causes the Model 2017A to behave like Data
Communications Equipment, transmitting data on RS-232 pin 3 and
receiving data on pin 2. Remember: The switch setting is always from
the point of view of the Model 2017A, not the connected equipment.
3
4
+
RCV G XMT
-
-
+
DCE
DTE
Figure 1. The Model 2017A
Figure 2. The DCE/DTE switch
Figure 3. The active/passive switch
Terminal
Block
DCE/DTE
Switch
Active/Passive
Switch
TX
RCV
PWR
AC
Adapter
Active
Passive
Active/passive
Switch
