When you turn the unit off in that fashion (physically hitting the power
button), the S24 PCMCIA card has its VCC turned off. In other words, the
radio is OFF... you can't even send MAC-level (WNMP) pings to the device.
Realize that if you sleep the unit (i.e. let its autoOff timer elapse w/o
any kind of activity, including directed IP network traffic), it's not
actually in sleep mode. Instead, we wrote the driver to switch off the LCD
and some other sneaky stuff. In this state, the radio is still on and will
respond to WNMP pings. In fact, you'l notice that if you send through any
directed packets, the device should "wake back up" (switch its LCD back on).
The device will move from this state to an actual sleep mode as described
above (VCC Off) after a developer-definable # of ticks. We had to implement
the driver in this fashion for reasons beyond the scope of this response.
At any rate, you _always_ want to try a NetLibConnectionRefresh() before
socket calls to avoid this problem. Always assume the device will lose its
connection (i.e. it's powered off) when you don't think it will! Users do
the darndest things.
-Jeff Ishaq
The Windward Group
-----Original Message-----
From: B. Flaumenhaft [mailto:
Sent: Friday, November 05, 1999 3:19 PM
To: [EMAIL PROTECTED]
Subject: Re: netErrNoInterfaces on power off?
In case anyone was curious ... I wasn't calling NetLibConnectionRefresh()
before using the socket code, which is apparently required by Symbol.
>Folks - I'm using the Symbol s24 and NetLib calls to make TCP/IP
connections.
>
>The consistent behavior I'm getting (with my application only) is that when
>the power shuts off (through user pressing button or auto-off), after the
>power is turned on again my application immediately receives
>netErrNoInterfaces error when trying to use socket calls.
