Front Panel Leds; Table 2-1 Led Indicators - ZyXEL Communications U-90E User Manual

U-90E Data/Fax Modem

2.1.1 Front Panel LEDs

The following table describes the LED indicators.
LEDs Description
HS High Speed mode indicator, lights ON when your modem is operating in V.34 or V.90
mode; flashes when your modem is in Handshaking State.
AA Auto-Answer indicator lights ON when your modem is in the Auto Answer Mode; and
Flashes when modem rings. In error control mode, it flashes when retransmitting.
CD Carrier Detect indicator, lights ON when a valid carrier is detected present on the line.
OH Off-Hook indicator lights ON when your modem is in data mode or off-hook and lights
OFF when your modem is in talk mode or on-hook.
DTR Data Terminal Ready indicator, lights ON when your DTE or computer indicates that it
is ready to begin communication and lights OFF when DTE is not ready to transmit
data.
DSR DTE mode. Data Set Ready Indicator, lights ON when the modem is ready for
communication and lights OFF when the modem is not ready.
CTS DTE mode. Clear To Send indicator, lights ON when modem can accept data for
transmission. It indicates the signal status of RS232 signal CTS.
RTS DTE mode. Request To Send indicator, indicates the signal status of RS232 signal
RTS from DTE. RTS is used for hardware flow control in asynchronous data
transmission.
TXD Transmit indicator, ON when your DTE/computer transmits data on the serial port.
RXD Receive indicator, ON when your DTE/computer receives data on the serial port.
SQ Signal Quality Indicator, ON when signal quality is good, OFF when signal quality is
bad, and flashes when signal quality is marginal or during power up to indicate an
error condition.
TST Test indicator, ON when modem is in the test mode.
2-2

Table 2-1 LED Indicators

Modem Installation