One Mile Radio Telescope
|"OI"||Parameters are passed to the hardware interface|
|"EH"||(Enquire Heading) a passive command that will cause the hardware interface to respond|
|"NV"||(Non Volatile) Sets the non volatile memory. (Valid range of encoder destinations. This command is only carried out if test switch 1 is on.)|
OI <HA speed><HA dir><HA track><HA dest><DEC speed><DEC dir><DEC dest>
NV <HA Limit 1><HA Limit 2><DEC Limit 1><DEC Limit 2>
All commands are terminated by an ASCII <CR>.
Always sent after a command
ST<valid command><Limit switches><HA control><HA encoder><DEC Control><DEC encoder>
Any attempt to send a new command whilst a response is being received is not allowed, and will be ignored. This is to prevent commands being queued up, and responses being misinterpreted for previous commands.
RS232 is used - "8 none and 1" at 9600 baud
|2||HA Dir||+ (Move HA
- (Move HA > param)
May be clear if HA speed is set to Park
|3||HA Track||No track)
|4||HA Dest||unsigned 16 bit encoder Hour Angle|
|6||DEC Dir||+ (Move DEC
- (Move DEC > param)
May be clear if DEC speed is set to Brake
|7||DEC Dest||unsigned 16 bit encoder Declination|
would instruct the dish to move the HA axis slowly while the encoder reads greater than 3456. DEC Brake is on, No sidereal tracking.
Note we work in 16 bit encoder units: we don't know about base 60, or base 24!
All fields are in ASCII comma separated variable format.
Numeric fields may have 0 or more characters. e.g. the above example could be typed in on a VDU:
... and would mean the same.
|7||Limit switch 7||Interface OK||unsigned
Hour Angle encoder
|6||Limit switch 6|
|5||Limit switch 5|
|4||Limit switch 4||Tracking
|Dec Brake is off|
|3||Limit switch 3||HA motor running Eastward||Dec motor running Southward|
|Limit switch 2||HA motor running Westward||Dec motor running Northward|
|Limit switch 1||HA motor running fast||Dec motor running fast|
|0||Command OK||Limit switch 0||HA motor running slow||Dec motor running slow|
This reports back to the PC.
For the above command example we will get this response:
The "DOS Console" applications sends
..and we get
.. and we continue...
The "Interface OK" bit reports that interface has a problem or is operating OK.
This could be due to Illegal command, safety shut down.
|0||HA extreme -|
|1||HA safe -|
|2||HA safe +|
|3||HA extreme +|
|4||Dec extreme -|
|5||Dec safe -|
|6||Dec safe +|
|7||Dec extreme +|
1.02 26/4/2000 Common Response Field 3 bit 4 added. We now report the tracking motor running state.