Pipe And Hub Information

A "hub" is an ASCOM tool for allowing multiple programs to connect to ASCOM drivers that would otherwise only work with a single program.  The "Hub" hub is the simplest such program.  Hub goes to a lot of trouble to do nothing but pass through commands exactly as they are given.  It just mediates access for multiple programs.

Pipe is also a hub.  It can be used instead of the "Hub" hub as an ASCOM linkage debugger.  Pipe is a hub that can be inserted in between any two or more ASCOM components so that the traffic between these components can be monitored.  Pipe goes to a lot of trouble to do nothing but log traffic and pass through commands exactly as they are given.

Simple Usage

1. Select "Hub" or "Pipe" from the client chooser
2. From the Hub or Pipe setup dialog choose Device(s)
3. Close Hub or Pipe setup dialog and connect to devices via the client programs

What Hub does:

• It is an ASCOM "hub" for telescope, dome, and focuser connections in any combination.

What Hub does not do:

• Hub has no "handset" like GUI window.  It is just a hub.  For a handset GUI use POTH.

What Pipe does:

• It is an ASCOM "hub" for telescope, dome, and focuser connections in any combination.
• Logs ASCOM commands and responses to a window and a file for diagnostic evaluation.
• Errors raised from the driver (whatever Pipe is connected to) will also be displayed and logged, before being passed up to the client (whatever has connected to Pipe).

What neither Pipe nor Hub do:

• They do not precondition commands as they pass through.
• They do not test for and correct error conditions.
• They do no dome slaving or focuser temperature compensation

More complex things to do with Pipe

• There are control checkboxes on the main window for selecting sets of interesting commands.  They can be toggled at any time.
• There are [Connect] buttons for manually connecting to the desired drivers (as specified in the set-up dialog), or the client software can be left to do all connect operations.
• The logged data shows up in a scrolling area of the main Pipe window.
• There is a [Mark] button for inserting a “Mark” into the log for later discovery.
• There is a log file kept in the directory that Pipe.exe is found. By default, this is “C:\Program Files\Common Files\ASCOM\Telescope”. Each time Pipe is run it copies Pipe.log to Pipe.bak and restarts Pipe.log at zero length. While the displayed log in the main window throws away the older entries as it goes, the log file contains the entire session.
• There is a [Clear] button that will zero the current log file and clear the logging window. Clear will not copy the existing log to Pipe.bak.
• There is an Enable/Disable button that allows temporary suspension of logging.  ASCOM commands will still be passing through.
• If the [Advanced] button in the setup dialog is used to expose the advanced area, and a given driver is connected, then the capabilities area will be filled out for review. This will require Pipe to generate and send a series of requests to the drivers. None of these values can be changed.

Programmers Information

• Errors raised from the driver (whatever Hub or Pipe is connected to) will also be passed up to the client (whatever is connected to Hub or Pipe).  Pipe will also log the errors.
• Both support early and late binding from clients.  For late bindings, the "Name" property will return "Pipe->(driver name)".  For early bindings, the "Name" property will return "I_Pipe->(driver name)".  The "I" feature will likely be dropped after sufficient early binding testing by the ASCOM comunity.
• Both support early and late binding to drivers.  Early binding will be attempted first, classic ASCOM late binding will attempted as fall back.  Late binding can be forced for test purposes by putting a registry entry into Hub or Pipe's ASCOM registry area as "ForceLate".  ForceLate would be a string set to "True".