ZyXEL Communications 2864 Series, User Manual, Page: 39 / 267

3–3
The following four indicators have different meanings depending on whether the
modem is connected to a DTE (computer or terminal) through either of the parallel
or serial interfaces (SP or PCP is ON, DTE mode) or whether the modem is con-
nected to a printer through the parallel port interface (PRP is ON, printer mode).
AA Auto Answer indicator; lights up when the modem is in auto answer
mode; flashes when modem rings.
CD Carrier Detect indicator; lights up when a valid carrier is detected
present on the line.
TXD Transmit Data indicator; lights up when your DTE/computer trans-
mits data to the modem.
RXD Receive Data indicator; lights up when your DTE/computer receives
data from the modem.
DTR
POL
DTE mode: Data Terminal Ready indicator; lights up when the DTE
or computer indicates that it is ready for communication by raising
the corresponding RS232 signal.
Printer mode: Printer On Line indicator; indicates the status of the
printer’s "Select" (SLCT) signal. It lights up when the printer is se-
lected and is available for data transfer.
DSR
PSL
DTE mode: Data Set Ready indicator; lights up when modem is
ready for communication.
Printer mode: Printer SeLect signal; indicates the signal status of
"-Select In" from modem to printer. It lights up when printer is ena-
bled to input data.
RTS
PPE
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.
Printer mode: Printer Paper End indicator; lights up when the print-
er is out of paper. It indicates the signal status of "PE" from the print-
er.
CTS
PER
DTE mode: Clear To Send indicator; lights up when modem can ac-
cept data for transmission. It indicates the signal status of RS232
signal CTS.
Printer mode: Printer ERror indicator; lights up when an error con-
dition exists in the printer, e.g., out ot paper or not on-line. It indi-
cates the signal status of "-Error" from the printer.