Schweitzer Engineering Laboratories SEL-2020 - Transparent Communications

Date Code 20010518 Settings 6-11
SEL-2020 Instruction Manual
Table 6.4: SET P Port Communications Settings Information (continued)
Setting Comment
AUTO_HELP
Prompt. Automatic help messages enabled (Y/N).
Description: Default setting is AUTO_HELP=Y. You can disable Auto-Help on a port
by setting AUTO_HELP=N. Auto-Help provides correct commands and command
syntax messages when you enter an incorrect command or command syntax. If you
disable Auto-Help on a Master port, you can request help with the HELP command.
TERTIME1
Prompt. First delay time (0 to 600 seconds).
Description. You enter a time that a port must be idle before checking for the
termination string. For a description of transparent communications, see the Transparent
Communications subsection following this table.
TERSTRING
Prompt. Termination string.
Description. You enter a string that will terminate transparent communications. The
default is \004, the code for <Ctrl-D>. For a description of transparent communications,
see the Transparent Communications subsection following this table.
TERTIME2
Prompt. Second delay time (0 to 600 seconds).
Description. You enter a time the port must be idle, after receiving the termination
string, before terminating transparent communications. For a description of transparent
communications, see the Transparent Communications subsection following this table.
EIA-232 Character
7 or 8
Databits
Start Bit
Optional
Parity
1 or 2
Stopbits
DWG: 2020_EIA232.vsd
Figure 6.2: EIA-232 Character Format
Transparent Communications
Transparent communications allow a master device to communicate directly with an IED or
printer through the SEL-2020. You enter the transparent communications mode using the PORT
command from the SEL-2020 command set or using a special user-defined command string you
set with the TRANS setting (see SET U subsection in this section).
Broadcast communications are similar to transparent communications, except that a master port
communicates with multiple IEDs simultaneously. Broadcast communications can only be
entered using the BROADCAST command.