Installation
22
User’s Manual - DSP19.2 Fast Poll Modem
Connecting to an RS-232 Device
The modem back panel provides a female, 9-pin RS-232 connector that accepts an attached
RS-232 device (see Figure 2-2 on page 10). This connector accepts a standard connection
to a DTE (RTU) that conforms to the pin assignments shown under “RS-232 (DTE)
Interface” on page 28.
Connecting to an RS-485 Device
The modem rear panel provide an RJ-11C module jack connector for a 4-pin RS-485 or RS-
422 interface in the event that your DTE or RTU does not support the RS-232 interface (see
Figure 2-2 on page 10 and Figure 2-7).
The pin assignments for the RS-485 interface are listed in Table 2-5.
Pin #6
Pin #1
Figure 2-7. Pin Locations on the Modem’s RJ-11C Jack
Table 2-5. RJ-11C Modular Jack Pin Assignments
RJ-11 Pin Number…
Corresponds to Signal Name
Modem Input or Output
1 Not
Used
NA
2
RxD+
Output
3 RxD- Output
4
TxD+
Input
5 TxD- Input
6
Not Used
NA
