Sel 751A, Instruction Manual

Page: 349 / 640

7.31
Date Code 20100129 Instruction Manual SEL-751A Relay
Communications
SEL ASCII Protocol and Commands
Only download firmware to the front port.
LOOPBACK Command
The LOO command (see Table 7.27 ) is used for testing the M
IRRORED
B
ITS
communications channel for proper communication. For more information on
M
IRRORED
B
ITS
, see Appendix I: M
IRRORED
B
ITS
Communications . With the
transmitter of the communications channel physically looped back to the
receiver, the M
IRRORED
B
ITS
addressing will be wrong and ROK will be
deasserted. The LOO command tells the M
IRRORED
B
ITS
software to
temporarily expect to see its own data looped back as its input. In this mode,
LBOK will assert if error-free data are received. The
LOO command with just
the channel specifier, enables looped back mode on that channel for five
minutes, while the inputs are forced to the default values.
.
=>>
LOO A <Enter>
Loopback will be enabled on Mirrored Bits channel A for the next 5 minutes.
The RMB values will be forced to default values while loopback is enabled.
Are you sure (Y/N)?
=>>
If only one M
IRRORED
B
ITS
port is enabled, the channel specifier (A or B)
may be omitted. To enable loopback mode for other than the 5-minute default,
enter the desired number of minutes (1–5000) as a command parameter. To
allow the loopback data to modify the RMB values, include the DATA
parameter.
=>>
LOO 10 DATA <Enter>
Loopback will be enabled on Mirrored Bits channel A for the next 10 minutes.
The RMB values will be allowed to change while loopback is enabled.
Are you sure (Y/N)?
N <Enter>
Canceled.
=>>
To disable loopback mode before the selected number of minutes, re-issue the
LOO command with the R parameter. The R parameter returns the device to
normal operation. If both M
IRRORED
B
ITS
channels are enabled, omitting the
channel specifier in the disable command will cause both channels to be
disabled.
=>>
LOO R <Enter>
Loopback is disabled on both channels.
=>>
Table 7.26 L_D Command (Load Firmware)
Command Description Access Level
L_D Download firmware to the control. 2
Table 7.27 LOO Command
Command Description Access Level
LOO Enable loopback testing of M
IRRORED
B
ITS
chan-
nels.
2
LOO A Enable loopback on M
IRRORED
B
ITS
Channel A
for the next 5 minutes.
2
LOO B Enable loopback on M
IRRORED
B
ITS
Channel B for
the next 5 minutes.
2