3-8 Installation Date Code 20010518
SEL-2020 Instruction Manual
Baud Rate
The default baud rate for the SEL-2020 front port, Port F, is 2400 baud. You can change the
Port F baud rate, and the other Port F communication parameters using the SET P command.
You can force the Port F baud rate to 2400 baud by hardware jumper selection (see Table 3.4).
The default baud rate for all rear panel communication ports is 9600 baud. You can change the
baud rate for each of these ports and the associated communication parameters with the SET P
setting command. With an SEL relay attached to one of the rear ports, the SEL-2020 will
automatically set the baud rate to match the relay baud rate when you request the SEL-2020 to
perform auto-configuration. With other IEDs attached to the ports, the SEL-2020 baud rate is
automatically set to match the attached IED baud rate when you request the SEL-2020 to perform
the auto-baud function.
To change the communication baud rate with a device, you should change the baud rate on the
device first, either by baud rate jumper, dip switch or software setting, then you should change
the baud rate setting on the associated SEL-2020 port using the SET P command. (See
Section 6: Settings for more information on making settings changes.)
Master Device to SEL-2020 Communication
Some Master devices, such as RTUs, cannot accept unsolicited messages, requiring that they
only receive a response to a request they send. When you interface the SEL-2020 with such a
device, you must make sure that the SEL-2020 does not send any auto-messages to the device
unless the SEL-2020 first receives a request. Use the SET U command to create user-defined
commands that will trigger the appropriate auto-message response.
You must use the same precaution when you interface the SEL-2020 with a master device using
the LMD protocol.
Passwords
Factory-set passwords are:
Level 1 = OTTER
Level 2 = TAIL
You can set your own passwords with the PASSWORD command, or you can disable the
password protection with jumper selection (see Table 3.4). (See Section 5: Commands for
more information on access levels and password control.)
Data Collection Periods
You can set the SEL-2020 Communications Processor to collect data from attached devices on an
exception basis, i.e., only when an event occurs, and you can set the SEL-2020 to collect data on
a regular, periodic basis. Each SEL-2020 port collects data independently, based on your
settings, and you can set each port to collect data in different ways using separate message
trigger conditions and data request messages. Likewise, each SEL-2020 port responds to
requests for data independently, based on your settings. In either case, the SEL-2020 will not
issue or respond to another request for data on the same port until the previous request has been
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