Serial and then some

[Mark Wieder]

Thomas-

Saturday, March 5, 2005, 8:40:22 AM, you wrote:

TMI> I need things like:
TMI> Do you really need to wait for a response after having sent a command?
TMI> Do we know what types of responses will come, what to expect?
TMI> Where do we look to know what to expect when looking at a new device?
TMI> Are there similarities with devices and responses?
TMI> Is there a list of commands to send?
TMI> Is there a simple way of understanding the 'why' of these commands?

The generic answer to all these questions is "no".

TMI> Why do some devices need certain LF CR etc.?

As they say, the nice thing about standards is that there are so many
to choose from...

You might think of sending data through the serial port as being like
sending data to a text file. There's really no constraint on what you
put in there, but if you write text in German and send it to someone
who only speaks Portuguese the results won't be very rewarding.

If you've got a device hanging on the serial port, though, it will
probably expect certain things - modems will intercept properly
formatted AT commands, for example, and pass along anything else. If
you have a modem on a serial port, try sending it an "+++ATI" and a
return. It should respond with status information about the current
configuration.

The Hayes AT modem command set
http://www.engplanet.com/content/Modem.html
http://www.computerhope.com/atcom.htm

-- 
-Mark Wieder
 mwieder at ahsoftware.net