INDI Library v0.3
July 17th, 2005

Running an INDI server
======================

Client applications communiate to INDI driver through the INDI server. 

Usage: indiserver [options] [driver ...]
Purpose: INDI Server
Options:
 -p p  : alternate IP port, default 7624
 -r n  : max restart attempts, default 2
 -vv   : more verbose to stderr
Remaining args are names of INDI drivers to run.

For example, to run LX200GPS driver on port 8000, type in:

	indiserver -p 8000 lx200gps
	
Different clients have different methods of connecting to the indiserver. Refer to your client documenation for more details.


Developing device drivers
=========================

Developers interested in developing their own device drivers under INDI should refer to the INDI Developers Manual at http://indi.sf.net/manual

Supported Devices:
==================

 ** Telescope
	+ LX200 Generic
	+ LX200 Classic
	+ LX200 Autostar
	+ LX200 16"
	+ LX200 GPS
	+ NewGT
	+ NexStar 5i/8i
	+ NexStar GPS, CGE, AS-GT
        + Astro-Physics AP
    	+ Astro-Electronic FS-2
    	+ Losmandy Gemini
    	+ Mel Bartels Controllers
	+ Vixen SkySensor 2000
	+ Argo Navis
	+ SkyCommander
	+ Temma Takahashi

 ** CCD
	+ Finger Lakes Instruments
	+ Apogee (Experimental)
	+ SBIG (Experimental)

 ** Video
	+ Any Video4Linux (V4L 1 and V4L 2) compatible camera
	+ Philips webcam
	+ Meade Lunar Planetary Imager (Experimental)

 ** Focuser
	+ Meade LX200GPS Microfocuser
	+ Meade 1206 Primary Mirror Focuser
	+ JMI NGF Series
	+ JMI MOTOFOCUS

 ** Filter Wheel
	+ Finger Lakes Instruments filter wheel


INDI Architecture and Construction
==================================

The code here demonstrates the use of INDI, an Instrument-Neutral Device
Interface protocol. See http://www.clearskyinstitute.com/INDI/INDI.pdf.

Architecture:

    Typical INDI Client / Server / Driver / Device connectivity:


    INDI Client 1 ----|                  |---- INDI Driver A  ---- Dev X
                      |                  |
    INDI Client 2 ----|                  |---- INDI Driver B  ---- Dev Y
                      |                  |                     |
     ...              |--- indiserver ---|                     |-- Dev Z
                      |                  |
                      |                  |
    INDI Client n ----|                  |---- INDI Driver C  ---- Dev T


     Client       INET       Server       UNIX     Driver          Hardware
     processes    sockets    process      pipes    processes       devices



    Indiserver is the public network access point where one or more INDI Clients
    may contact one or more INDI Drivers. Indiserver launches each driver
    process and arranges for it to receive the INDI protocol from Clients on
    its stdin and expects to find commands destined for Clients on the
    driver's stdout. Anything arriving from a driver process' stderr is copied
    to indiserver's stderr.

    Indiserver only provides convenient port, fork and data steering services.
    If desired, a Client may run and connect to INDI Drivers directly.

Construction:

    An INDI driver typically consists of one .c file, eg, mydriver.c, which
    #includes indiapi.h to access the reference API declarations. It is
    compiled then linked with indidrivermain.o, eventloop.o ,liblilxml.a, and indicom.a (optional) to
    form an INDI process. These supporting files contain the implementation of
    the INDI Driver API and need not be changed in any way. Note that
    evenloop.[ch] provide a nice callback facility independent of INDI which
    may be used in other projects if desired.
    
    The driver implementation, again in our example mydriver.c, does not
    contain a main() but is expected to operate as an event-driver program.
    The driver must implement each ISxxx() function but never call them. The
    IS() functions are called by the reference implementation main() as messages
    arrive from Clients. Within each IS function the driver performs the
    desired tasks then may report back to the Client by calling the IDxxx()
    functions.

    The reference API provides IE() functions to allow the driver to add its
    own callback functions if desired. The driver can arrange for functions to
    be called when reading a file descriptor will not block; when a time
    interval has expired; or when there is no other client traffic in progress.

    The sample indiserver is a stand alone process that may be used to run one
    or more INDI-compliant drivers. It takes the names of each driver process
    to run in its command line args.