Nexstar SynScan - Manual (Page 21)

Physical Connection Diagram
RJ-11 Connector
RJ-11
N C
RD
GND
N C
TD
N C
I I
I
The Back of the Pinout
9
Additional Commands
Sending a track rate through 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 (proximately 8 times of sidereal rate),
then the = 480.
2. Separate TRACKRATE into two bytes, such that (TRACKRATE =
+ 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,
b. Negative Azm tracking: 80, 3, 16, 7, TrackRateHighByte, TrackRateLowByte,
c. Positive Alt tracking: 80, 3, 17, 6, TrackRateHighByte, TrackRateLowByte,
d. Negative Alt tracking: 80, 3, 17, 7, TrackRateHighByte, TrackRateLowByte,
4. The number 35 is returned from the hand control.
Sending a slow-Goto command through to the hand control
1. Convert the angle position to a number. Example: if the desired position is
then = = 10,252,743
2. Separate into three bytes such that
PosHighByte * 65536 + PosMedByte * 256 + PosLowByte). Example: PosHighByte
156, PosMedByte = 11 3, PosLowByte = 199
3. Send the following 8 bytes:
a. Azm Slow 80, 4, 16, 23, PosHighByte, PosMedByte, PosLowByte,
b. Alt Slow 80, 4, 17, 23, PosHighByte, PosMedByte, PosLowByte,
4. The number 35 is returned from the hand control.
Reseting the position of or Alt
1. Convert the angle position to a number, same as Slow-Goto example.\
2. Send the following 8 bytes:
a. Azm Set Position: 80, 4, 16, 4, PosHighByte, PosMedByte, PosLowByte,
b. Alt Set Position: 80, 4, 17, 4, PosHighByte, PosMedByte, PosLowByte,
3. The number 35 is returned from the hand control.
3.