Eia Interface Leads (Signals) - Toshiba Strata DK 280 Installation Manual

A T D is typed for voice calls, and A T D D for data
calls.
Installation instructions for these devices are provided
in Subsections 6.9.4 through 6.9.7. Call paths and
scenarios for five types of data test calls are provided
in Subsection 6.9.8, paragraph 2 - paragraph 6. Step-
by-step data calling procedures are provided in t.he
Data Interface User Guide.
,
6.9.2 EIA Interface leads (Signals)
Both DlUs operate with nine standard EIA RS-232
interface leads (signals) on which signaling data is
transmitted and received. RPCls and DlUs connect to
serial data devices with standard RS-232 cables,
available from telephone supply stores (see Figures 6-
25 - 6-31). The RPCI-DVPDIU-DVPDIU-DS requires
nine signals for some applications, but can function
with eight using modular cords and connectors with
RJ45/DB25 adapters for other applications. If
uncertain which signals are necessary for an
application, all nine should be connected.
IMPORTANT!
1. The RPCI-DI and PDIU-DI is always a
DCE device; the PDIU-DS may be a DTE
or DCE, depending on how its internal
jumpers (1 - 9) are configured.
2. In the descriptions below, when a signal is
ON, its potential is about seven volts
positive relative to signal ground (pin 7);
when a signal is OFF, it is about 7 volts
negative relative to the signal ground
(pin 7).
Frame Ground (FG, Pin 1)
The FG signal (EIA circuit AA) is a protective or safety
ground which is bonded to the PDIU-DVPDIU-DS
PCB. If required by local codes, the FG should be
connected to external ground.
Signal Ground (SC, Pin 7)
The SG signal (EIA circuit AB) establishes the
common ground reference for all other PDIU and data
device signals and must be wired for all applications.
Transmit Data (TD, Pin 2)
DTE devices transmit and DCE devices receive data
on the TD lead (EIA circuit BA). Before the DTE
device can transmit the TD signal, the RTS, CTS,
DSR, and DTR signals (all discussed below) must be
ON. The TD signal is OFF in the idle state.
Receive Data (RD, Pin 3)
The DCE device transmits data to the DTE device on
the RD lead (EIA circuit BB); the DTE receives data on
the RD.
Request to Send (RTS, Pin 4)
Some DTE devices send an RTS signal (EIA circuit
CA) to the DCE device when they are ready to
transmit data on the TD lead. If the DTE device does
not generate the RTS signal, the DIU DIP switch SW1 -
4 should be set ON to inform the RPCI or DIU.
Sometimes, the DTE/DCE device may use RTS/CTS
for Ready/Busy type flow control, in these cases DIP
switch SWl-4 should be OFF (see Figure 6-33 for DIP
switch information).
Clear to Send (CTS, Pin 5)
The DCE device sends the CTS signal (EIA circuit CB)
which indicates that it is prepared to transmit data to
the line side. The DCE device sends this signal only
when it receives the RTS signal from the DTE device.
Sometimes, the DTE/DCE device may use RTS/CTS
for Ready/Busy type flow control; in these cases, dip
switch SWI-4 should be OFF (see Figure 6-33 for DIP
switch information).
Data Set Ready (DSR, Pin 6)
When connected to the communication channel and
prepared to exchange control characters to initiate
data transmission, the DCE device sends the DSR
signal (EIA circuit CC) to the DTE device. If the PDIU
DIP switch SWI-2 is set ON, DSR will be ON
continuously; if the switch is set OFF, DSR folldws
DTR (if DSR is ON, DTR is ON, etc.) SWI-2 should be
OFF in most cases (see Figure 6-33 for DIP switch
information).
Data Carrier Detect (DCD, Pin 8)
The DCE device sends the DCD signal (DCD, Pin 8)
when receiving the carrier signal on the line side.
Before transmitting or receiving data, most DTE
devices require that the DCD be ON. If the carrier
signal is removed by the remote end or lost due to a
fault condition on the line, the DCE notifies the DTE
device by an OFF condition with the DCD signal. The
PDIU dip switch SWI-2 is set ON to set the DCD ON
continuously. If set OFF, the DCD signal will only be
ON when connection between two DlUs is established
and OFF when a connection is not established. SWl-2
is set OFF when the DTE/DCE uses the DTR/DSR
signals for Ready/Busy flow control (see Figure 6-33
for dip switch information).
January 1996
6-39