![Schweitzer Engineering Laboratories SEL-421-4 Instruction Manual Download Page 96](http://html.mh-extra.com/html/schweitzer-engineering-laboratories/sel-421-4/sel-421-4_instruction-manual_1216726096.webp)
2.46
SEL-421 Relay
Instruction Manual
Date Code 20171021
Installation
Connection
IRIG-B Input Connections
The SEL-421 accepts a demodulated IRIG-B signal through two types of rear-
panel connectors. These IRIG-B inputs are the BNC connector labeled
IRIG-B
and
Pin 4 (
+
) and Pin 6 (
–
) of the DB-9 rear-panel serial port labeled
PORT 1
. When you
use the
PORT 1
input, ensure that you connect Pins 4 and 6 with the proper polarity.
Communications Ports Connections on page 2.47
for other DB-9 connector
pinouts and additional details.
These inputs accept the dc shift time code generator output (demodulated)
IRIG-B signal with positive edge on the time mark. For more information on
IRIG-B and the SEL-421, see
.
The
PORT 1
IRIG-B input connects to a 2.5 k
grounded resistor and goes
through a single logic signal buffer. The
PORT 1
IRIG-B is equipped with robust
ESD and overvoltage protection but is not optically isolated. When you are using
the
PORT 1
input, ensure that you connect Pin 4 (
+
) and Pin 6 (
–
) with the proper
polarity.
The IRIG network should be properly terminated with an external termination
resistor (SEL 240-1802, BNC Tee, and SEL 240-1800, BNC terminator, 50 ohm)
placed on the unit that is farthest from the source. This termination provides
impedance matching of the cable for the best possible signal-to-noise ratio.
Where distance between the SEL-421 and the IRIG-B sending device exceeds the
cable length recommended for conventional EIA-232 metallic conductor cables,
you can use transceivers to provide isolation and to establish communication to
remote locations.
Conventional fiber-optic and telephone modems do not support IRIG-B signal
transmission. The SEL-2810 Fiber-Optic Transceiver/Modem includes a channel
for the IRIG-B time code. These transceivers enable you to synchronize time pre-
cisely from IRIG-B time code generators (such as the SEL-2032 Communica-
tions Processor) over a fiber-optic communications link.
Topology Mismatch
Connection does not match supported topology
Green
COMMISSION
LED
Blinking
Red
COMMISSION
LED
ON
Green LED:
PORT 6A
–
PORT 6H
OFF—mismatched/unused
ON—matched
Red LED:
PORT 6A
–
PORT 6H
Blinking—mismatched
ON—matched
OFF—ports unused
Topology Matched
Connection matches topology
Green
COMMISSION
LED
ON
Red
COMMISSION
LED
OFF
Green LED:
PORT 6A
–
PORT 6H
ON
Red LED:
PORT 6A
–
PORT 6H
OFF
N/A
A commissioned port experiences an error
Green
COMMISSION
LED
ON
Red
COMMISSION
LED
OFF
Green LED:
PORT 6A
–
PORT 6H
ON
Red LED:
PORT 6A
–
PORT 6H
Blinking—failed port
Table 2.12
TiDL LED Status (Sheet 2 of 2)
State
Description
LED Status
Summary of Contents for SEL-421-4
Page 6: ...This page intentionally left blank ...
Page 14: ...This page intentionally left blank ...
Page 30: ...This page intentionally left blank ...
Page 104: ...This page intentionally left blank ...
Page 128: ...This page intentionally left blank ...
Page 536: ...This page intentionally left blank ...
Page 584: ...This page intentionally left blank ...
Page 616: ...This page intentionally left blank ...
Page 696: ...This page intentionally left blank ...
Page 750: ...This page intentionally left blank ...
Page 755: ...Instruction Manual PM400 01 NB SEL 400 Series Relays Instruction Manual 20171006 ...
Page 776: ...This page intentionally left blank ...
Page 932: ...This page intentionally left blank ...
Page 976: ...This page intentionally left blank ...
Page 1024: ...This page intentionally left blank ...
Page 1038: ...This page intentionally left blank ...
Page 1064: ...This page intentionally left blank ...
Page 1128: ...This page intentionally left blank ...
Page 1206: ...This page intentionally left blank ...
Page 1316: ...This page intentionally left blank ...
Page 1350: ...This page intentionally left blank ...
Page 1464: ...This page intentionally left blank ...
Page 1468: ...This page intentionally left blank ...
Page 1492: ...This page intentionally left blank ...
Page 1518: ...This page intentionally left blank ...