RimuCAT bridges the FlexRadio network protocol to the interfaces your software already speaks - CAT, Hamlib rigctld, PTT, Winkeyer, OTRSP, N1MM+ spots, USB passthrough, and the Wavelog and Cloudlog logbooks - so logging programs, digital-mode software, and automation tools can control your radio from Linux.
RimuCAT is the radio control component of the RimuSDR suite. It translates the FlexRadio network protocol into the interfaces external software expects, and presents each one as a port that programs reach over TCP, UDP, a virtual serial port, or a real serial device.
The recommended connection method for modern software such as WSJT-X and N1MM+.
For software that only supports serial port CAT, such as Fldigi and older logging programs.
/dev/
Every port pairs a protocol with the way your software reaches it.
/tmp/ttyCAT0/dev/ttyUSB0A port is one endpoint RimuCAT exposes to other software. Each port has a protocol - the language it speaks - and a transport - how software reaches it. Create as many ports as you need; they all run at the same time, and each one is configured from the same Add Port dialog.
rigctld network dialect, for software configured as Hamlib NET rigctl rather than a Kenwood rig. TCP or virtual serial. One slice, or two in dual VFO mode.
RimuCAT must be connected to the same FlexRadio station as RimuSDR before any port will work. Follow these steps to get RimuCAT running.
The CAT port provides bidirectional radio control — frequency, mode, and PTT — to external software. Multiple simultaneous CAT connections are supported; use a different port number for each application and they can all control the radio at the same time.
/tmp/ttyCAT0) and enter it in your application
The virtual port exists only while RimuCAT is running and connected. If RimuCAT is closed or disconnected, the port disappears and applications holding it open will need to reconnect.
/dev/ttyUSB0)
On Linux, access to serial port devices requires membership in the dialout group. If the port does not appear or RimuCAT cannot open it, add your user account to the group with sudo usermod -aG dialout $USER and then log out and back in for the change to take effect.
The Hamlib port speaks the rigctld network dialect. Use it for software that is configured as Hamlib NET rigctl instead of a Kenwood rig, such as WSJT-X, Fldigi, Not1MM, and GridTracker. More than one program can connect to the same Hamlib port at the same time.
In your software, set the rig type to Hamlib NET rigctl and the network server to 127.0.0.1:4532. In Single VFO mode the client sees VFO A only, and split is not available; Dual VFO binds a second slice as VFO B, and the client must also be set up for two VFOs or it will use VFO A alone.
/tmp/ttyCAT1) and enter it in your application
TCP is the usual choice here, because rigctl clients connect over the network. Select Virtual Serial only if your software expects the rigctl dialect on a serial device.
The PTT port provides a dedicated transmit keying interface separate from CAT control. Use a PTT port when your application needs to key the radio for transmit independently of CAT commands. PTT ports are serial only - there is no TCP or UDP option.
With Auto Switch TX Slice enabled, the port makes its slice the transmit slice before keying. Clear it if the port should key the radio without changing which slice transmits - the slice selector then disappears, because the port no longer needs one.
/dev/ttyUSB0)
On Linux, access to serial port devices requires membership in the dialout group. If RimuCAT cannot open the port, add your user account to the group with sudo usermod -aG dialout $USER and then log out and back in for the change to take effect.
The Winkeyer port emulates a WinKey CW keyer and sends the keying to the radio's own CW engine. Use it with contest loggers that drive a WinKey, such as N1MM+, Win-Test, and TR4W. There is no slice to select - CW keying is a radio-wide function.
/tmp/ttyWKY0) and enter it as the keyer port in your logging software
Leave the Advanced Serial Settings alone. RimuCAT sets the WinKey line rate of 1200 baud with two stop bits by itself, whatever the advanced fields show. RimuCAT identifies itself as a first-generation WinKey, so select the WK1 keyer type if your software asks which generation to use.
Use TCP for software that can reach a WinKey over the network. Loggers that expect a keyer on a COM port need the Virtual Serial option instead.
The OTRSP port implements the Open Two Radio Switching Protocol for SO2R contest operation. It switches receive audio and the transmit slice between two slices on the one radio, so a logger treats your FlexRadio as two stations. An OTRSP port binds two slices rather than one.
/tmp/ttyOTRSP0) and enter it as the SO2R device in your logger
The two slices must both exist on the radio before the port can switch between them. Create them in RimuSDR first.
RX commands set which slice you hear and where it sits in the stereo image; TX commands set which slice transmits. The port mirrors the resulting audio state to the transmit monitor and CW sidetone.
The N1MM+ Spot port receives bandmap spots broadcast by N1MM+ Logger and places them on the panadapter in RimuSDR, colored by their status. It carries spots in one direction only and needs no slice. UDP is its only transport.
The UDP port in RimuCAT must match the port N1MM+ broadcasts to, and N1MM+ must be sending to the address of the computer RimuCAT runs on. Spots that N1MM+ deletes are removed from the panadapter as well.
A passthrough port relays raw bytes in both directions between a serial port on your computer and a FlexRadio USB cable, so software on the PC can reach hardware plugged into the radio. Set the cable up as a passthrough cable on the radio first, then select it here by serial number. There is no slice and no protocol translation - the bytes pass through untouched.
/tmp/ttyPASS0) and enter it in the software that talks to the attached hardware
If the cable list is empty, the radio has no USB cable configured for passthrough. Configure the cable on the radio, then reopen the dialog.
/dev/ttyACM0)
On Linux, access to serial port devices requires membership in the dialout group. If the port does not appear or RimuCAT cannot open it, add your user account to the group with sudo usermod -aG dialout $USER and then log out and back in for the change to take effect.
The Wavelog/Cloudlog port is the one port with no serial, TCP, or UDP transport to configure. It talks to your logbook's HTTP API directly, pushing live frequency, mode, and power as you operate, and answering click-to-tune requests from the log. There is no WaveLogGate or CloudlogCAT process to install.
There is no slice to select. The radio name is taken from the FlexRadio nickname, and the port follows whichever slice is active, so the logbook always shows the slice you are working. The Wavelog / Cloudlog Setup Guide covers the logbook side, including where to find the API key.
Step-by-step integration guides for connecting digital-mode and logging applications to RimuSDR.