Date Code 20060320 Instruction Manual SEL-311C Relay
Appendix K
Unsolicited Fast SER Protocol
Introduction
This appendix describes special binary Sequential Events Recorder (Fast
SER) messages that are not included in Section 10: Serial Port
Communications and Commands. Devices with embedded processing
capability can use these messages to enable and accept unsolicited Fast SER
messages from the SEL-311C Relay.
SEL relays and communications processors have two separate data streams
that share the same serial port. The normal serial interface consists of ASCII
character commands and reports that are intelligible to people using a terminal
or terminal emulation package. The binary data streams can interrupt the
ASCII data stream to obtain information, and then allow the ASCII data
stream to continue. This mechanism allows a single communications channel
to be used for ASCII communications (e.g., transmission of a long event
report) interleaved with short bursts of binary data to support fast acquisition
of metering or SER data. To exploit this feature, the device connected to the
other end of the link requires software that uses the separate data streams. The
binary commands and ASCII commands can also be accessed by a device that
does not interleave the data streams.