41
Additional RS-232 Commands
Sending a track rate through RS-232 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
(approximately 8 times of sidereal rate), then the
TRACKRATE
=
480.
2. Separate
TRACKRATE
into two bytes, such that (
TRACKRATE
=
TrackRateHighByte*256 + TrackRateLowByte
).
For example
TRACKRATE
=
480
, then
TrackRateHighByte = 1
,
TrackRateLowByte = 224
.
3.
To send a tracking rate, send the following 8 bytes:
• Positive Azm tracking:
80, 3, 16, 6, TrackRateHighByte, TrackRateLowByte, 0, 0
• Negative Azm tracking:
80, 3, 16, 7, TrackRateHighByte, TrackRateLowByte, 0, 0
• Positive Alt tracking:
80, 3, 17, 6, TrackRateHighByte, TrackRateLowByte, 0, 0
• Negative Alt tracking:
80, 3, 17, 7, TrackRateHighByte, TrackRateLowByte, 0, 0
4.
The number
35
is returned from the hand control.
Sending a slow-Goto command through RS232 to the hand control
1.
Convert the angle position to a 24-bit 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:
• Azm Slow Goto:
80, 4, 16, 23, PosHighByte, PosMedByte, PosLowByte, 0
• Alt Slow Goto:
80, 4, 17, 23, PosHighByte, PosMedByte, PosLowByte, 0
4.
The number
35
is returned from the hand control.
Resetting the position of Az or Alt
1.
Convert the angle position to a 24-bit number, same as Slow-Goto example.
2.
Send the following 8 bytes:
• Azm Set Position:
80, 4, 16, 4, PosHighByte, PosMedByte, PosLowByte, 0
• Alt Set Position:
80, 4, 17, 4, PosHighByte, PosMedByte, PosLowByte, 0
3.
The number 35 is returned from the hand control.
