7-2
Serial Port Communications and Commands
Date Code 20020129
SEL-387E Instruction Manual
Cables
Connect the SEL-387E Relay to another device using the appropriate cable. The pin definitions
for Ports 1, 2, 3, and 4 are given on the relay rear panel and detailed in Table 7.1.
A drawing of the 9-pin port connector and pin definitions appears in Figure 7.1.
(female chassis connectors as viewed from outside panel)
Figure 7.1: SEL-387E Relay Serial Port Connectors
Pinouts for EIA-232 and EIA-485 ports follow:
Table 7.1: Serial Port Pin Definitions
Pin
Number
Port 1 Rear
EIA-485
Port 2 Rear
EIA-232 with
IRIG-B
Port 3 Rear
EIA-232
Port 4 Front
EIA-232
1
+TX (Out)
N/C or +5 Vdc*
N/C or +5 Vdc*
N/C
2
-TX (Out)
RXD (In)
RXD (In)
RXD (In)
3
+RX (In)
TXD (Out)
TXD (Out)
TXD (Out)
4
-RX (In)
N/C or +IRIG-B*
N/C
N/C
5 Shield
GND
GND
GND
6
N/C
N/C or -IRIG-B*
N/C
N/C
7
+IRIG-B
RTS (Out)
RTS (Out)
RTS (Out)
8
-IRIG-B
CTS (In)
CTS (In)
CTS (In)
9 NA
GND GND
GND
* Install a jumper to use the 5 V connection, and remove a solder jumper to disable the IRIG-B
input. See
Section 2: Installation
for more information.
Port 1 is an EIA-485 protocol connection on the rear of the relay. It accepts a pluggable terminal
block that supports wire sizes from 24 AWG up to 12 AWG. The connector is supplied with the
relay. Ports 2, 3, and 4 are EIA-232 protocol connections with Ports 2 and 3 on the rear of the
relay and Port 4 on the front of the relay. These female connectors are 9-pin, D-subminiature