RigExpert TI-7 is a device for operating phone, CW and digital modes using personal computer with USB port. It provides:

• Transceiver audio interface Analog audio interface is a connection to transceiver audio output (external
speaker connector or line output) and transceiver audio input (microphone connector or line input). Audio interface enables operating digital modes, recording and playing voice, as well as other useful functions (such as measuring levels of a signal from the air) by using a computer.

• Input (main and sub channels) and output volume levels are adjusted by potentiometers on the front panel of the device.

• CAT interface for various transceiver models CAT (Computer Aided Transceiver) system provides control of transceiver
frequency, operating mode and other functions by computer software. Normally, modern transceivers have serial (with various signal levels) link providing CAT interface. A virtual COM port is created for the CAT system so the computer software can communicate to the transceiver.

• FSK output FSK (Frequency Shift Keying) is a popular method of transmitting digital messages over radio primarily used in radioteletype (RTTY) mode. Most transceivers provide FSK modulator feature to make the RTTY signal stable
and clear. A separate virtual COM port is created for the FSK function.

• PTT and CW output functions Transceivers provide PTT (Push To Talk) and CW (Continuous Wave) keyer
inputs to allow setting the transmitter on or off and operating CW using external device (PTT pedal, CW bug or paddle, terminal node controller, or personal computer). A separate virtual COM port is created for PTT/CW outputs.

• Squelch input Some software, such as EchoLink, requires the interface to provide a squelch
input to detect if the radio channel is busy. In RigExpert TI-7, the squelch input is assigned to the DCD line of the virtual
COM port used for PTT and CW outputs.