Schweitzer Engineering Laboratories SEL-751 - Figure 7.8 IRIG-B Input Via Fiber-Optic EIA-232 Port 2 (SEL-2401;2404;2407 Time Source); Figure 7.9 EIA-232 DB-9 Connector Pin Numbers; Table 7.3 EIA-232;EIA-485 Serial Port Pin Functions

7.8
SEL-751 Relay Instruction Manual Date Code 20170927
Communications
Communications Interfaces
You cannot use B01–B02 input or Port 3 input if you use Port 2 for IRIG-B input.
Set Global setting IRIG TIME SOURCE to TIME_SRC := IRIG2.
Figure 7.8 IRIG-B Input Via Fiber-Optic EIA-232 Port 2 (SEL-2401/2404/
2407 Time Source)
+5 Vdc Power Supply
Serial port power can provide as much as 0.25 A total from all of the +5 Vdc
pins. Some SEL communications devices require the +5 Vdc power supply.
This +5 Vdc power is available on Pin 1 only on EIA-232 Port 3 and EIA-232
Port 4.
Connect Your
PC to the Relay
The front port of the SEL-751 is a standard female 9-pin connector with pin
numbering shown in Figure 7.9. The pinout assignments for this port are
shown in Table 7.3. You can connect to a standard 9-pin computer port with
SEL Cable C234R; wiring for this cable is shown in Figure 7.10. SEL Cable
C234R and other cables are available from SEL. Use the SEL-5801 Cable
Selector Software to select an appropriate cable for another application. This
software is available for free download from the SEL website at selinc.com.
For best performance, SEL Cable C234R should not be more than 15 m (50 ft)
long. For long-distance communications and for electrical isolation of
communications ports, use the SEL family of fiber-optic transceivers. Contact
SEL for more details on these devices.
Port Connector and
Communications
Cables
Figure 7.9 shows the front-panel EIA-232 serial port (PORT F) DB-9 connector
pinout for the SEL-751.
Figure 7.9 EIA-232 DB-9 Connector Pin Numbers
Table 7.3 shows the pin functions for the EIA-232 and EIA-485 serial ports.
SEL-2812MT
SEL-2401
SEL-2404
or
SEL-2407
IED
DB9
Mono-Plug
Jack
Use Fiber-Optic Cables
SEL C805 or SEL C807
SEL Cable
C654
Port 2
Set switch to “J1” for IRIG input
from SEL-2401, etc.
ST
ST
BNC
SEL-751
Table 7.3 EIA-232/EIA-485 Serial Port Pin Functions (Sheet 1 of 2)
Pin
a
PORT 3
EIA-232
PORT 3
EIA-485
a
PORT 4C
EIA-232
PORT 4A
EIA-485
a
PORT F
EIA-232
1 +5 Vdc +TX +5 Vdc +TX N/C
2 RXD –TX RXD –TX RXD
3 TXD +RX TXD +RX TXD
4 IRIG+ –RX N/C –RX N/C
5 GND Shield GND Shield GND
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