The S600+ adds four new RS-485 serial ports (COM 9 through COM
12), located in the lower half of the CPU module (see Figure 3-1).
For information on the communications port on the front panel which
can also act as Comm 2, refer to Chapter 5, Front Panel.
3.3.1 RS-232 Serial Port
The CPU module’s backplate provides two RS-232 (RS-232D)
communications ports labeled COM3 and COM4. The ports use FCC-
68 RJ-45 connectors. The COM3 and COM4 pin connections are
shown in Table 3-4. Figure 3-5 shows a sample pin connection.
Converters are commercially available to configure either 9-way D
type or 25-way D type connection. The ports support baud rates from
2400 to 57600 bps.
Table 3-4. COM3 and COM4 Pin Connections