You can check whether the Microsoft fix was installed through: ·
'My Computer' - 'Properties' - 'Hardware' - 'Device Manager' -
'Universal-Serial-Bus-Controller' - choose one of the controllers and
select 'Properties' - 'Driver' - 'Driver Details'. · ...
Modem On Hold: Allows you to receive incoming calls while keeping your
Internet connection on hold. Note: you need to have the "call waiting"
feature enabled on your phone line. Your phone company can arrange to
have this installed, if not currently av...
Frequent disconnection on a USB modem running on WinXP may be
easily corrected by installing a fix from Microsoft that can be
downloaded from:
http://support.microsoft.com/default.aspx?scid=kb;EN-US;q307271
[http://support.microsoft.com/default.aspx?s...
For Half-Duplex 2-wire operation, Please confirm that the
communications program being used by the computers controls Request To
Send (RTS). This is very important, when a Converter detects an ON (+
voltage) for RTS the transmitter is switched from HIGH ...
DCE Data Communications Equipment, is typically a Modem or other
device that connects to a Network. DTE Data Terminal Equipment, is
typically a Computer.
DCE and DTE reference is used to identify the source or origination
of signals. A local DTE (PC) connects to a DCE (Modem), the Modem
connects to a Network, the remote end of the Network has a second
Modem used to connect to the remote PC.
A Null Modem is used to connect the one DCE device to another. A Null
Modem crossover connects the Receive and Transmit Data and the Control
Signals.
The cable should be connected straight through.
Distance limitations on any unit that operates in pairs can be
extended using a TAIL CIRCUIT. This involves using two pairs of the
unit daisy-chained together through the DTE Interface. However, since
the units are both DCE, a crossover cable must be used...
There is confusion regarding the polarity of the RS485 and RS422
transmit and receive signal pairs. The RS-485 and RS-422
specifications define the transmit and receive signal pairs as XMT-A,
XMT-B, RCV-A, and RCV-B. Unfortunately most manufacturers have...
First of all, the communication equipment must control Request To
Send (RTS). This is very important, when a modem detects an ON (+
voltage) on Pin 4 (RTS) it switches the transmitter from HIGH
IMPEDANCE to LOW IMPEDANCE. If two or more pieces of equipme...
The problem is the P/C AC power source has only two wires are
connected: +/- DC, no earth ground. In this case voltages of 75 to
85VAC between the P/C chassis (Signal Ground) and Earth can be found.
Grounding the P/C chassis fixed the problem.
