Change the base TCP port¶

The CAT Control applet runs up to four rigctld-compatible TCP servers on consecutive ports starting from a configurable base. Change the base port when the default conflicts with another application on your system.

Before you start¶

AetherSDR must be connected to the radio. The CAT applet requires an active radio connection.
Open the CAT Control applet by clicking the CAT tray button on the right sidebar if it is not already visible.

Steps¶

In the CAT Control applet, locate the Base: label and its text field at the bottom of the applet.
Click the Base: field and type the new port number. Valid range: 1024–65535. Default: 4532.
Press Enter or Tab to confirm. If the value is outside the valid range, it snaps back to 4532.
The new base port is saved immediately to CatTcpPort.
If Enable TCP is currently active, all four servers restart automatically on the new ports (base, base+1, base+2, base+3). No further action is needed.

What each control does¶

Control	Kind	Default	Valid range	Persisted key	Behavior
`Base:`	Text field	`4532`	1024–65535	`CatTcpPort`	Sets the base TCP port. Channels A, B, C, D bind to base, base+1, base+2, base+3. Out-of-range values snap to `4532`. If `Enable TCP` is on, servers restart with the new port immediately.
`Enable TCP`	Toggle button	Off	—	—	Starts or stops all four rigctld TCP servers. Also persists the current base port to `CatTcpPort` when toggled.
`Enable TTY`	Toggle button	Off	—	—	Starts or stops all four PTY symlinks at `/tmp/AetherSDR-CAT-A` through `/tmp/AetherSDR-CAT-D`. Linux and macOS only.
A/B/C/D rows	Indicator	`(stopped)`	—	—	Shows per-channel TCP status as `:<port> (N clients)` when a server is running, or `(stopped)` when it is not. Also shows the PTY symlink path for each channel when TTY is enabled. Channel badges are colour-coded by slice.

Tips¶

Choose a base port that leaves the next three consecutive ports free. For example, a base of 4532 uses 4532, 4533, 4534, and 4535.
If you change the port while Enable TCP is off, the servers will start on the new port the next time you click Enable TCP.
On Linux and macOS, click Enable TTY to expose each channel as a virtual serial port. Point your logging software to the corresponding /tmp/AetherSDR-CAT-A through /tmp/AetherSDR-CAT-D symlink instead of a TCP socket.

Troubleshooting¶

Servers do not restart after changing the port — Confirm you pressed Enter or Tab to finish editing the Base: field. Clicking away without committing the edit may not apply the change.
Port field snaps back to 4532 — The value entered was outside the 1024–65535 range. Enter a value within that range.
Server fails to start on the new port — Another application may already be using that port or one of the three consecutive ports. Choose a different base port.
PTY symlinks do not appear — Enable TTY is available on Linux and macOS only. Confirm you clicked Enable TTY and that AetherSDR has write access to /tmp.