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Chapter 2 - Installation
2.6 Modem LED Indicators
The MT2834 has ten LED diagnostic indicators.
1. Receive Data (RCV). This LED blinks when data is being received, on
for a space, off for a mark. The state of this RCV LED matches that of
the RCV circuit on Pin 3 of the RS232C/V.24 interface.
2. Transmit Data (XMT). This LED blinks when data is being transmitted,
on for a space, off for a mark. The state of this LED matches that of the
XMT circuit on Pin 2 of the RS232C/V.24 interface.
3. Carrier ON (CO). This LED lights when a valid carrier tone has been
detected.
4. 28,800 bps (28.8). This LED is lit when the modem is connected at
28,800 bps.
5. 14,400 bps (14.4). This LED is lit when the modem is connected at
14,400 bps. Note that when both 28.8 and 14.4 LEDs light, modem is in
21,600-26,400 bps mode of operation.
6. 2400 bps (24). This LED is lit when the modem is connected at 2400
bps.
7. Off Hook (OH). This LED is lit when the phone line is “off hook”. This
occurs when the modem is dialing, on line, or answering a call. The
LED also flashes when the modem is pulse dialing in the Command
Mode.
8. Data Terminal Ready (DTR). When the DTR LED is lit, the modem is
permitted to answer an incoming call. When DTR goes off, a connected
modem disconnects if dependent on DTR. The state of this DTR LED
matches that of the DTR circuit on Pin 20 of the RS232C/V.24 interface.
9. Ring Indicator (RI). This LED is lit during the ringing interval as an
incoming call is received.
RCV XMT CO 28.8 14.4 24 OH DTR RI ERR