5. ELECTRICAL DESCRIPTION
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LZ T 123 7 605 P1C
Serial Data To Control Terminal (TD)
Pin 3
TD is an input signal, used by the external application to send data to the
Control Terminal.
5.2.4 Control Signals - RTS, CTS, DTR, DSR, DCD, RI
Request to Send (RTS)
Pin 7
Used to condition the Control Terminal for data transmission. The default
level is inactive by internal pull down.
The exact behaviour of RTS is defined by an AT command. Software or
hardware flow control can be selected. Hardware flow control is the default
selection.
The application must pull RTS high to enable transmission from the
Control Terminal.
Clear To Send (CTS)
Pin 8
CTS indicates that the Control Terminal is ready to transmit data. The
default level is high. You can define the exact behaviour of CTS through an
AT command, and can select software or hardware flow control.
Data Terminal Ready (DTR)
Pin 13
DTR indicates that the DTE is ready to send and receive data. It also acts
as a hardware ‘hang-up’, terminating calls when switched low. The signal
is active high. You can define the exact behaviour of DTR with an AT
command.
Data Set Ready (DSR)
Pin 6
An active DSR signal is sent from the Control Terminal to the application
(DTE) to confirm that a communications path has been established. DSR
has two modes of operation, use the AT command AT&S to set the mode.
Data Carrier Detect (DCD)
Pin 1
DCD indicates that the Control Terminal is receiving a valid carrier (data
signal) when high. You can define the exact behaviour of DCD with an AT
command.
Ring Indicator (RI)
Pin 10
RI indicates that a ringing signal is being received by the Control Terminal
when high. You can define the exact behaviour of RI with an AT
command.