ZyXEL Communications U-336SA - Manual (Page 22)

8 Installation
Figure 2-2 U-336SA Front Panel
Front Panel LEDs
PWR Power ON indicator, loghts up when your modem is turned
ON.
OH Off-Hook indicator, lights up when your modem is in data
mode or off-hook. It goes out when your modem is in talk
mode or on-hook.
AA Auto-Answer indicator, lights up when your modem is in the
Auto Answer Mode; flashes when modem rings. In error
control mode, it flashes when retransmitting.
DTR Data Terminal Ready indicator, lights up when your DTE or
computer indicates that it is ready to begin communication.
DSR DTE mode: Data Set Ready Indicator, lights up when the
modem is ready for communication.
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.
CD Carrier Detect indicator; lights up when a valid carrier is
detected present on the line.
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.