Schweitzer Engineering Laboratories SEL-2020, Instruction Manual

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2-6 General Description Date Code 20010518
SEL-2020 Instruction Manual
The SET A, automatic message setting command, establishes the message count, 0 to 12, of
active triggering equations and message strings used on each port. You are then prompted to
create the SEL
OGIC
Control Equations for message triggering and associated messages within the
framework of the SET A setting. (See Section 6: Settings. )
A
UTOMATIC
D
ATABASE
Database Structure
The SEL-2020 Data Area includes a database structured as shown in Figure 2.1 consisting of the
following defined regions: Global (GLOBAL), Local (LOCAL), Buffer (BUF), Data (D1-D8),
Archive (A1-A3), and User (USER). For a more complete description of the database, see
Section 9: Database .
PORT 1 PORT 2 PORT 16
1:LOCAL
1:BUF
1:D1
1:D2
1:D8
.
.
.
.
1:A1
1:A2
1:A3
1:USER
GLOBAL GLOBAL
2:LOCAL
2:BUF
2:D1
2:D2
2:D8
.
.
.
.
2:A1
2:A2
2:A3
2:USER
GLOBAL
16:LOCAL
16:BUF
16:D1
16:D2
16:D8
.
.
.
.
16:A1
16:A2
16:A3
16:USER
.
.
.
.
Figure 2.1: SEL-2020 Database Structure
Global Region
The Global region includes the following data which are common to all ports:
SEL-2020 FID String, Status and Configuration information, Date and Time, Global
elements, and Port F status.
Global elements are logical “1” when asserted or true, and “0” if not asserted or false. The
Global elements, as the name implies, are stored in the Global data region, which is available for
use by all ports. These elements can be used in any SEL
OGIC
Control Equation to define a
trigger condition. When the condition is true, the SEL-2020 sends the message associated with
the SEL
OGIC
Control Equation, such as requesting data or issuing a control command.