Re: [Hamlib-developer] Resource temporarily unavailable?

[Stephane F. <f4...@fr...>]

On Tue, Sep 18, 2001, John Roberts wrote:
> I'm hacking up testrig to try and put together an app to talk to my Icom 
> 756Pro. Below is the code and the output that I get. Any idea why I see 
> "Resource temporarily unavailable"?
 
Your program is fine. The problem lies with the poor robustness
of the current Icom backend (yeah, that's on my TODO list). 
To make a long story short, CI-V protocol uses a CSMA/CD bus system,
with TXD and RXD tied together. That's why when the backend
send "ff fe fe 5c e0 07 00 fd", it has to read (ie. empty)
what it just sent, before expecting the reply from the rig.
However, it looks like the receive ibuffer should be drained beforehand.
Right now, I don't know what the best solution. Anyway, read on...

> TX 8 bytes
> 0000	 ff fe fe 5c e0 07 00 fd	...\....
> RX 8 bytes
> 0000	 e0 07 00 fd fe fe e0 5c	.......\
         ^^^^^^^^^^^  ^^^^^^^^^^
 end of previous cmd     begining of the reply

> rig timeout after 2 chars or select error - Resource temporarily 
> unavailable!
> rig timeout after 0 chars or select error - Resource temporarily 
> unavailable!

oh, wait, I'm not sure, but I think I fixed this in the CVS repository,
which is the forthcoming Hamlib-1.1.2 (hopefully by next week). 
Can you checkout the CVS version and give it a try?

The other explanation could be the so-called transceive mode, i.e. the rig
which is sending asynchronously "events" notification. But according to
the traces, it's not likely.

As you can see, Hamlib is still in ALPHA stage, and badly needs programers
(I'm doing this on my spare time). Anyway, testers are more than needed too!

Cheers,
Stephane