Sony Ericsson GR 47 Technical Description page 31

Parameter
Application load capacitance
Application load resistance
GBBA/SEM/BMS 03:0001 Rev
GR47/GR48 Technical description
Clear To Send (CTS)
CTS is an output from the module. The signals on this circuit are used
to indicate that the DCE (the module when used for data transmission
purposes) is ready to transmit data. Default level is high.
The exact behaviour of CTS is defined by the AT+IFC command.
Software or hardware flow control can be selected.
This is a Dig. 2.75 CMOS Output and general characteristics are
applicable.
Tip: if only software flow control is to be used it becomes necessary
to assert RTS low or to connect RTS to CTS at the module.
Data Terminal Ready (DTR)
DTR is an input to the module. Signals from the DTE on this circuit
indicate the DTE is ready to transmit and receive data. DTR also acts
as a hardware 'hang-up' so that calls are terminated if DTR is OFF
(high).
Default level is ON (low). The exact behaviour of DTR is defined by
the AT&D command.
This is a Dig. 2.75 CMOS Input and general characteristics are
applicable.
Data Carrier Detect (DCD)
DCD is an output from the module. An ON (low) signal shall indicate
that a valid carrier (data signal) is being received by the DCE
(module). The exact behaviour of DCD is defined by the AT&C
command.
This is a Dig. 2.75 CMOS Output and general characteristics are
applicable.
Ring Indicator (RI)
RI is an output from the module. An ON (low) signal indicates a
ringing signal is being received by the DCE (module).
This is a Dig. 2.75 CMOS Output and general characteristic s are
applicable.
A
Limit
< 500 pF
> 1 MΩ
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