This is version 1.00. let's pull it apart!
| bit\byte | B11 | B10 | B09 | B08 | B07 | B06 | B05 | B04 | B03 | B02 | B01 | B00 |
| 7 |
Hour Angle parameter MSB
|
Hour Angle LSB
|
Declination parameter MSB
|
Declination parameter
LSB
|
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| 6 | ||||||||||||
| 5 | Sidereal Track | |||||||||||
| 4 | HA Brake off
(N/A) |
Dec Brake Off | ||||||||||
| 3 | Move HA < param |
Move Dec < param |
||||||||||
| 2 | Move HA > param |
Move Dec > param |
||||||||||
| 1 | HA Motor Fast | Dec Motor Fast |
||||||||||
| 0 | HA Motor Slow |
Dec Motor Slow |
This carries a simple instruction. e.g.
xx,xx,xx,xx,xx,xx,xx,45,34,56,xx,xx,xx
would instruct the dish to move the HA axis slowly while the encoder reads
greater than 3456. HA Brake off., No sidereal tracking.
Note we work in 16 bit encoder units: we don't know about base 60, or base 24!
| bit\byte | B11 | B10 | B09 | B08 | B07 | B06 | B05 | B04 | B03 | B02 | B01 | B00 |
| 7 | Limit switch 7 | Interface OK |
Hour Angle encoder MSB
|
Hour Angle encoder LSB
|
Declination encoder MSB
|
Declination encoder
LSB
|
||||||
| 6 | Limit switch 6 | |||||||||||
| 5 | Limit switch 5 | |||||||||||
| 4 | Limit switch 4 | HA Brake is off | Dec Brake is off | |||||||||
| 3 | Limit switch 3 | HA motor running Eastward | Dec motor running Southward | |||||||||
| 2 | Limit switch 2 | HA motor running Westward | Dec motor running Northward | |||||||||
| 1 | Limit switch 1 | HA motor running fast | Dec motor running fast | |||||||||
| 0 | Limit switch 0 | HA motor running slow | Dec motor running slow |
This reports status back to the PC. for the above example...
xx,xx,xx,xx,xx,00,15,36,f0,xx,xx,xx ....
xx,xx,xx,xx,xx,00,15,34,f0,xx,xx,xx
xx,xx,xx,xx,xx,00,15,34,58,xx,xx,xx
xx,xx,xx,xx,xx,00,10,34,54,xx,xx,xx
xx,xx,xx,xx,xx,00,00,34,52,xx,xx,xx
An "Interface OK" bit reports if the interface has a problem or is operating OK.
This could be: Illegal command, safety shut down, no frame from PC in last second...
| 0 | HA extreme - |
| 1 | HA safe - |
| 2 | HA safe + |
| 3 | HA extreme + |
| 4 | Dec extreme - |
| 5 | Dec safe - |
| 6 | Dec safe + |
| 7 | Dec extreme + |
Looks like we need only 7 byte frames - not 12!!