Sutron Corporation Satlink Operations & Maintenance Manual, Rev 8.04.2 11/3/2016 pg. 155
Each EXTBUF command must be prefixed with a telemetry indicator and followed with a
command option. For example TX1 EXTBUF SHOW will show the data in TX1 (the self-timed)
external buffer. The following are the options for the EXTBUF commands:
TXx EXTBUF APPEND [xx]
Adds data to the end of the external buffer.
TXx is the telemetry indicator. E.g. TX1
[xx] optionally specifies the number of bytes to append.
If the command is preceded with an exclamation point, Satlink will reply with an <ETX>.
Otherwise Satlink will say “Send transmission data. Finish with ETX (Ctrl-C).”
Follow the APPEND command with the data to be transmitted. If the number of bytes
was not specified, end of data needs to be indicated with an <ETX>.
Satlink will reply with “OK xx bytes added”.
TXx EXTBUF INSERT [xx]
Clears all existing data in the external buffer and then appends new data to the buffer.
Follows the same syntax rules as the APPEND command.
TXx EXTBUF SHOW
Shows data that is currently in the buffer. Will say "Buffer is empty" if there is no data.
TXx EXTBUF BYTES
Reports how many data bytes are in the buffer currently.
TXx EXTBUF SIZE
Reports the capacity of the buffer in bytes.
APPEND and INSERT are used by a logger to add data to the transmission buffer. These
commands follow special rules. If invoked in machine mode (e.g. "!TX1 EXTBUF INSERT"), Satlink
will reply with an ETX character (0x03) to the command. That is the queue for the logger to send
its transmission data to Satlink.
There are two ways of using the commands:
Provide the number of transmission data bytes that are to follow.
Terminate the data with an ETX character (0x03)
Please note that <ETX> can be sent via a terminal program by hitting Ctrl-C.
