Dditional rs232 commands – Sky-Watcher DOB16 User Manual
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Physical Connection Diagram
II
1= NC
2= RD
3= GND
4= NC
5= TD
6= NC
RD = 2
GND = 5
TD = 3
1 2
6
The Back of the DB9 Pinout
RJ-11 Connector
9
3
5
1
2 3
4
5 6
Sending a track rate through RS232 to the hand control
Multiply the desired tracking rate (arc seconds /second) by 4. For example: if the
desired track rate is 120 arc seconds/second (proximately 8 times of sidereal rate),
then the TRACKRATE = 480.
Separate TRACKRATE into two bytes, such that (TRACKRATE =
TrackRateHighByte*256 + TrackRateLowByte). For example TRACKRATE = 480,
then TrackRateHighByte = 1, TrackRateLowByte = 224.
To send a tracking rate, send the following 8 bytes:
1.
2.
3.
A
dditional RS232 Commands
a. Positive Azm tracking: 80, 3, 16, 6, TrackRateHighByte, TrackRateLowByte, 0, 0
b. Negative Azm tracking: 80, 3, 16, 7, TrackRateHighByte, TrackRateLowByte, 0, 0
c. Positive Alt tracking: 80, 3, 17, 6, TrackRateHighByte, TrackRateLowByte, 0, 0
d. Negative Alt tracking: 80, 3, 17, 7, TrackRateHighByte, TrackRateLowByte, 0, 0
The number 35 is returned from the hand control.
4.
Sending a slow-Goto command through RS232 to the hand control
Convert the angle position to a 24bit number. Example: if the desired position is 220?,
then POSITION_24BIT = (220/360)*224 = 10,252,743
Separate POSITION_24BIT into three bytes such that (POSITION_24BIT =
PosHighByte * 65536 + PosMedByte * 256 + PosLowByte). Example: PosHighByte =
156, PosMedByte = 113, PosLowByte = 199
Send the following 8 bytes:
1.
2.
3.
a. Azm Slow Goto: 80, 4, 16, 23, PosHighByte, PosMedByte, PosLowByte, 0
b. Alt Slow Goto: 80, 4, 17, 23, PosHighByte, PosMedByte, PosLowByte, 0
The number 35 is returned from the hand control.
4.
Resetting the position of Az or Alt
Convert the angle position to a 24bit number, same as Slow-Goto example.\
Send the following 8 bytes:
1.
2.
3.
a. Azm Set Position: 80, 4, 16, 4, PosHighByte, PosMedByte, PosLowByte, 0
b. Alt Set Position: 80, 4, 17, 4, PosHighByte, PosMedByte, PosLowByte, 0
The number 35 is returned from the hand control.