AA6E's Orion WebLog

Orion's Serial Interface

Some interesting features came to light when I was working with the serial port and the 'octl' program.. This is with firmware version 1.369, supported by version 1.2 of the Programmer's Reference Guide.

  • Command/response is not standardized for all commands. There are various “special” commands: “XX”, “?V”, “/”, etc. that don't fit into a standard format.

  • Most control commands generate response only on error. It would be more positive if there was an ACK/NAK response to every command. As it is, the only way you can test for a command's success is by waiting for an input timeout.

  • Queries are not standardized. "?CV" returns a variable length string, while "?TP" return a fixed zero-padded string.

  • "?S" - on transmit, the VSWR is not formatted as shown in the Guide. The response is a 3 digit number, which is equal to 256 x the VSWR reading, as far as can be told.

  • AGC and Step size for the subreceiver are not returned by the advertised queries. Instead, you get the main receiver data.

  • Serial port service is degraded when the control processor gets busy - e.g., by rapid multiple spins of the VFO knob. The external computer needs a way to detect firmware "overload" to suspend query & control operations.

  • Glitches have been observed. E.g., a "?BF" command (following an ?AF) can produce a "@AFxxx" response, depending on system history and load. Sometimes a query produces no response at all.

  • Even with 57 kb/s serial I/O, it takes ~1.2 seconds to completely read out the data provided on the LCD panel. The control protocol and the CPU probably both limit the responsiveness.

  • It would be efficient to have a command that would dump larger blocks of data in one transaction.

  • Front panel functions that aren't provided to the serial port: NB, NR, NOTCH, AM. RIT/XIT “activated” LED/button, MAIN/SUB RX activated, Lock/unlock status, Main/sub AF “mute” status, spectrum analyzer status (or results!).

-AA6E, 2/28/04

I'd be happy to have your comments or suggestions: email to martin /at/ aa6e.net.

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