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Appendix B - RS-232 Connection
You can control your CGE telescope with a computer via the RS-232 port on the computerized hand control and using an optional RS-232 cable (#93920). Once connected, the CGE can be controlled using popular astronomy software programs.

Communication Protocol:
CGE-i communicates at 9600 bits/sec, No parity and a stop bit. All angles are communicated with 16 bit angle and communicated using ASCII hexadecimal. Description Echo Goto Azm-Alt PC Command ASCII Kx B12AB, 4000 Hand Control Response X# # Notes Useful to check communication 10 characters sent. B=Command, 12AB=Azm, comma, 4000=Alt. If command conflicts with slew limits, there will be no action. Scope must be aligned. If command conflicts with slew limits, there will be no action. 10 characters returned, 12AB=Azm, comma, 4000=Alt, # Scope must be aligned 0=No, 1=Yes; "0" is ASCII character zero 0=No, 1=Yes

Goto Ra-Dec

R34AB, 12CE

#

Get Azm-Alt Get RA-Dec Cancel Goto Is Goto in Progress Is Alignment Complete Commands below available on version 1.6 o r l ater HC version Stop/Start Tracking

Z E M L J

12AB, 4000# 34AB, 12CE# # 0# or 1# 0# or 1#

32-bit goto RA-Dec 32-bit get RA-Dec Commands below available on version 2.2 o r l ater 32-bit goto Azm-Alt 32-bit get Azm-Alt

V Tx x= x= x= x= r34 e

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# 0 (Tracking off) 1 (A lt -A z on) 2 (EQ-N) 3 (EQ-S) AB0500,12CE0500

Two bytes representing V2.2 Alt-Az tracking requires alignment

# 34AB0500,12CE0500#

The last two characters will always be zero.

b34AB0500,12CE0500 z

# 34AB0500,12CE0500#

The last two characters will always be zero.

The cable required to interface to the telescope has an RS-232 male plug at one end and a 4-4 telephone jack at the other end. The wiring is as follows:

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Additional RS232 Commands
Send Any Track Rate Through RS232 To The Hand Control
1. 2. 3. Multiply the desired tracking rate (arcseconds/second) by 4. Example: if the desired trackrate is 150 arcseconds/second, then TRACKRATE = 600 Separate TRACKRATE into two bytes, such that (TRACKRATE = TrackRateHigh*256 + rackRateLow). Example: TrackRateHigh = 2 TrackRateLow = 88 To send a tracking rate, send the following 8 bytes: a. Positive Azm tracking: 80, 3, 16, 6, TrackRateHigh, TrackRateLow, 0, 0 b. Negative Azm tracking:80, 3, 16, 7, TrackRateHigh, TrackRateLow, 0, 0 c. Positive Alt tracking: 80, 3, 17, 6, TrackRateHigh, TrackRateLow, 0, 0 d. Negative Alt tracking: 80, 3, 17, 7, TrackRateHigh, TrackRateLow, 0, 0 The number 35 is returned from the handcontrol

4.

Send A Slow-Goto Command Through RS232 To The Hand Control (note: Only valid for motorcontrol version 4.1 or greater) 1. 2. 3. 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 = PosHigh*65536 + PosMed*256 + PosLow). Exampe: PosHigh = 156, PosMed = 113, PosLow = 199 Send the following 8 bytes: a. Azm Slow Goto: 80, 4, 16, 23, PosHigh, PosMed, PosLow, 0 b. Alt Slow Goto: 80, 4, 17, 23, PosHigh, PosMed, PosLow, 0 The number 35 is returned from the handcontrol

4.

Re se t T he P o si ti o n O f Az m O r Al t 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, PosHigh, PosMed, PosLow, 0 b. Alt Set Position: 80, 4, 17, 4, PosHigh, PosMed, PosLow, 0 3. The number 35 is returned from the handcontrol 4. Note: If using Motorcontrol version less than 4.1, then send: a. Azm Set Position: 80, 3, 16, 4, PosHigh, PosMed, PosLow, 0 b. Alt Set Position: 80, 3, 17, 4, PosHigh, PosMed, PosLow, 0

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