SKY-WATCHER AZ GOTO Instruction Manual page 20

Physical Connection Diagram
RJ-11 Connector
1
2
3
4
5
6
Sending a track rate through RS232 to the hand control
1.
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.
2.
Separate
3.
TrackRateHighByte*256 + TrackRateLowByte). For example TRACKRATE = 480,
then TrackRateHighByte = 1, TrackRateLowByte = 224.
To send a tracking rate, send the following 8 bytes:
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
1. Convert the angle position to a 24bit number. Example: if the desired position is 220?,
then POSITION_24BIT = (220/360)*224 = 10,252,743
2. Separate POSITION_24BIT into three bytes such that (POSITION_24BIT =
PosHighByte * 65536 + PosMedByte * 256 + PosLowByte). Example: PosHighByte =
156, PosMedByte = 113, PosLowByte = 199
3. Send the following 8 bytes:
a. Azm Slow Goto: 80, 4, 16, 23, PosHighByte, PosMedByte, PosLowByte, 0
b. Alt Slow Goto: 80, 4, 17, 23, PosHighByte, PosMedByte, PosLowByte, 0
4. The number 35 is returned from the hand control.
Reseting the position of Az or Alt
1. Convert the angle position to a 24bit number, same as Slow-Goto example.\
2.
Send the following 8 bytes:
a. Azm Set Position: 80, 4, 16, 4, PosHighByte, PosMedByte, PosLowByte, 0
b. Alt Set Position: 80, 4, 17, 4, PosHighByte, PosMedByte, PosLowByte, 0
3. The number 35 is returned from the hand control.
1= NC
2= RD
RD = 2
3= GND
GND = 5
4= NC
5= TD
TD = 3
6= NC
The Back of the DB9 Pinout
TRACKRATE into two
II
1 2 3
6
bytes, such that (TRACKRATE
5
9
=