Schweitzer Engineering Laboratories SEL-2020 - Arch_En; Nackn; SET C - Calibration; SET L - Logic (Ports 1-16)

2-16 General Description Date Code 20010518
SEL-2020 Instruction Manual
NACKn
If the connected device watches for Acknowledge/Negative Acknowledge strings for message
confirmation, use the NACKn setting to set the Negative Acknowledge string to be sent
whenever the checksum verification fails.
ARCH_EN
The ARCH_EN setting prompt is only presented if optional nonvolatile Flash memory is
available. Set ARCH_EN=Y to enable the use of the nonvolatile Flash memory for this port.
Other prompts will then be presented to request ISSUEnA and MESGnA settings for the Archive
data areas.
USER
You use the USER setting to establish the size of a message area for temporarily storing data.
The STORE command is used separately to place the message string and other data in the USER
data region of a particular port. Even if you do not set the USER setting, the SET M command
will, if necessary, automatically increase the size of the message area to accommodate the SET
M settings.
SET U - User-Defined Commands (Ports 1-16)
The SET U command allows you to create user-defined commands that other devices send to the
SEL-2020. You can also use this setting to trigger action from selected SEL relay auto-messages
(Event, Status, and Group). The user-defined commands can supplement or replace the prepro-
grammed SEL-2020 command set. This may be helpful if the device sending messages has some
of the same commands as the SEL-2020, but different action is desired from the SEL-2020.
SET M - Data Movement (Ports 1-16)
The SET M command allows you to scale and move data to a User region. This allows you to
customize data scaling and organization in a central location. This can significantly reduce data
access time by reducing the number of requests necessary to get the data of interest. On port 16,
the SET M command also defines what data is visible to DNP.
SET L - Logic (Ports 1-16)
The SET L command allows you to define control equations for all port-specific set and clear
bits (SBR1 - SBR16, SRB1 - SRB16, CBR1 - CBR16, and CRB1 - CRB16).
SET C - Calibration
There is normally no need for you to calibrate the SEL-2020 because it is fully calibrated at the
factory. Calibration checks are only needed if you change EPROMs to upgrade the SEL-2020
firmware, and even then it is unlikely that any changes will be needed.