Operating instructions

TECHNICAL QUICK REFERENCE
128
Front Panel Lights (External Modems)
Symbol Meaning Status
AA ........ Auto Answer.................Answer mode: ON when register S0 is set to 1 or higher (Auto
Answer), and when answering a call; OFF when modem originates
a call. Light flashes when there is an incoming call.
CD......... Carrier Detect ...............ON if modem receives a valid data signal (carrier) from a remote
modem, indicating that data transmission is possible. Always ON if
CD override is ON (&C0).
RD......... Received Data...............Flashes when modem sends result codes or passes received data
bits from remote.
SD......... Send Data .....................Flashes when computer sends a data bit to modem.
TR......... Data Terminal Ready.....ON if modem receives a DTR signal from computer. Always ON
(modem ignores DTR) if the DTR override is ON (&D0).
CS ......... Clear to Send.................ON until modem lowers CTS when Transmit Data hardware flow
control is enabled (&H1, &H3).
ARQ/ Error Control/
FAX....... Fax Operations ..............Data Mode: Automatic Repeat Request. ON if modem is set to &M4 or
&M5 and successfully establishes an error control connection. Flashes
when modem retransmits data to remote modem. Fax Mode: Flashes to
indicate fax mode.