Re: NTP sever on an isolated Network

Steve Kostecke <kostecke@xxxxxxx> writes:

On 2009-01-12, Unruh <unruh-spam@xxxxxxxxxxxxxx> wrote:

In general serial ports do NOT supply power. The RS232 standard does not
state that any power should be supplied. Now, some may create serial ports
which do, but those are out of standard and will depend on whose serial
port you have. Ie, if you want to be sure, use the usb port for power. The
standard says they have to supply power (5V)

You're assuming that all computers / SBCs / Embedded Systems have a USB
port.

Agreed, it you do not have a usb port, you cannot get power from it.
Then you have to get power from elsewhere. Getting it from the serial port
is almost certainly not going to work (but yes, if you are extremely lucky
you might be able to ) The chances of that embedded system having usb port are probably
higher than the chances that such an embedded system has a PCI or ISA slot
to stick in some external brand of serial port which can supply power.
The easiest way of getting the 8-30V that the Garmin 18PC needs is
probably from a laptop powersupply brick. The 4.5-5.5 volts that the 18LVC needs
might be a cell phone charger or the usb port.

.

Relevant Pages