TIPS FOR THE USB PORT SETTINGS
4
SECTION 1 ABOUT “DTR” AND “RTS”
Applicable products: IC-7300, IC-7851 (as of March 2016)
When connecting the above Icom amateur base transceivers to a PC using a USB cable, and operating an
RTTY or logging software application, set either the “DTR” or “RTS” items in the transceiver Set mode
settings of “USB SEND,” “USB Keying (CW),” and “USB Keying (RTTY).”
This section describes how to set these items.
Figure 1-1 Set mode screen for IC-7300
Figure 1-2 Set mode screen for IC-7851
DTR stands for Data Terminal Ready, and RTS stands for
Request To Send. They originated from the RS-232C standard,
which is a unified standard for the control signal line.
The SEND and CW/RTTY keying signals from the PC through the
DTR and RTS terminals of the RS-232C port or the sound card
are applied to the ACC socket on the transceiver. On some
transceivers with an RS-232C port, these signals are directly
applied from the DTR and RTS terminals on the PC’s RS-232C
port through an RS-232C cable.
Output signals
to the RS-232C
connector
Software
operation
Mark
Space
RX
TX
DTR
RTS
*When SEND is assigned to the
RTS, and RTTY keying is assigned
to the DTR terminals.
(Used for the transceiver’s
transmit and receive switching.)
(Front view)
Figure 1-3 RS-232C connector pin
assignment (DB9)
1
2
3
4
5
6
7
8
9
DCD
RTS
RXD
DSR
TXD
DTR
RI
GND
CTS
