CHAPTER 4: Hardvare Overview
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4.3 Channel Status Indicators
The LinkUp 5294 is equipped with a full RS-232C status display capable of monitoring the status of any
selected port. Each of the indicators is briefly described below. ON indicates that the LinkUp 5294 is
either transmitting or receiving the signal as appropriate.
•
DCE/DTE (Data Communications Equipment/Data Terminal Equipment) —
An LED lit for one of
these indicates that the port selected has been software-optioned to communicate with either a
modem (DTE) or directly to a terminal or printer (DCE).
•
TXD/RXD (Transmit Data/Receive Data) —
These are data signals that indicate transmission of data
either to or from the LinkUp 5294.
•
RTS (Request to Send) —
The LinkUp 5294 provides this signal when optioned as DTE or when it
expects to receive the signal when optioned as DCE.
•
CTS (Clear To Send) —
The LinkUp 5294 provides this signal when optioned as DCE and expects it
from the modem when optioned as DTE.
• DTR (Data Terminal Ready) —
The LinkUp 5294 provides this signal when optioned as DTE or
expects to receive the signal when optioned as DCE. Additionally, when configured as DTE auto-
answer, this signal will be provided only after receipt of the Rl (Ring Indicator) signal from the
modem.
•
DSR (Data Set Ready) —
The LinkUp 5294 provides this signal when optioned as DCE or expects to
receive it from the modem when optioned as DTE.
•
CD (Carrier Detect) —
This LED is lit when the LinkUp 5294 has detected a carrier signal from a
remote modem. If no detectable carrier signal is present, or the remote modem hangs up, this LED
is turned off.
•
RI/SYN (Ring Indicator/Data Sync) —
This is a dual-function LED. It displays Ring Indicate when
the selected port is optioned as DTE/auto-answer in synchronous or asynchronous operation. On
the sync port, this LED is always off.
•
TXC/RXC (Transmit Clock/Receive Clock) —
When on, this LED indicates the presence of
synchronous clock signals which are required for the sync port. These must always be present for
Port 0 and Port 1.
•
I/O FAULT —
On SYNC ports, this LED flashes if a framing error occurs. On asynchronous ports
this LED indicates parity errors.
During normal operation in async DTE mode, the following should be on:
DTE, RTS, CTS, DSR and CD
RI will be on during ringing, and DTR will come on after RI is detected.
During normal operation in async DCE mode, the following should be on:
DCE, RTS, CTS, DTR, DSR and CD
In both DTE and DCE modes, the TXD and RXD lights will blink during data transfer.
