Schweitzer Engineering Laboratories SEL-587Z - Hardware Protocol; Software Protocols

6.7
Date Code 20020903 SEL-587Z Instruction Manual
Serial Port Communications
Communications Protocols
The SEL-587Z goes to Access Level 2 [see ACC and 2AC (Access and
2Access) on page 7.2 in Section 7: ASCII Command Reference] when you
enter the 2AC command at the Access Level 1 prompt:
=>2AC <Enter>
Access Level 2
The relay issues the following prompt in Access Level 2:
=>>
The relay recognizes commands CLO through SET from Access Level 2. For
example, enter the SET command at the Access Level 2 computer screen
prompt to set the relay:
=>>SET <Enter>
While you are in Access Level 2, the relay recognizes any of the commands
available in the lower access levels.
Hardware
Protocol
SEL-587Z relays equipped with the EIA-232 port support RTS/CTS hardware
handshaking.
To enable hardware handshaking, use the SET P command (or front-panel
{SET} pushbutton) to set RTSCTS = Y. Disable hardware handshaking by
setting RTSCTS = N.
 If RTSCTS = N, the relay permanently asserts the RTS line.
 If RTSCTS = Y, the relay deasserts RTS when it is unable to
receive characters.
 If RTSCTS = Y, the relay does not send characters until the
CTS input is asserted.
Software
Protocols
Software protocols consist of standard SEL ASCII, SEL Distributed Port
Switch Protocol (LMD), SEL Fast Meter, SEL Compressed ASCII, and
Modbus
®
RTU. The Modbus protocol is available on the rear port only. Based
upon the port PROTO setting, the relay activates SEL ASCII, SEL LMD, or
Modbus RTU (rear port) protocol. SEL Fast Meter and SEL Compressed
ASCII commands are always active if the protocol is SEL ASCII or SEL
LMD. SEL Fast Meter and SEL Compressed ASCII are not available if the
protocol is Modbus RTU.
SEL ASCII Protocol
SEL ASCII protocol is for manual and automatic communications.
All commands received by the relay must be of the form:
<command><CR> or <command><CRLF>
A command transmitted to the relay should consist of the command followed
by either a CR (carriage return) or a CRLF (carriage return and line feed). You
can truncate commands to the first three characters. For example, EVENT 1
<Enter> would become EVE 1 <Enter>. You can use upper- and lowercase
characters without distinction, except in passwords.