Connecting machines

A machine in GRBL Server is a laser controller you've added to the server. Each machine has a name, a connection (USB / Serial, or WiFi / Ethernet), a firmware (GRBL, or GRBL-ESP32 / FluidNC), a port or address (a COM port for USB machines, an IP address for networked ones), a description, a work area and, optionally, its maximum power.

This page shows you how to add machines over each connection, what the work area and maximum power mean, how to read the connection status, and how to move a machine by hand.

Connections & firmware

Adding a machine comes down to two choices: how it's connected and what firmware it runs. You pick the connection first, and GRBL Server then offers only the firmware that works over it.

Adding a USB machine

1. Plug the controller into the host computer by USB and switch it on.
2. If the board uses a CH-340 USB-to-serial chip — most inexpensive GRBL boards do — and Windows hasn't loaded a driver for it, download and install the CH-340 driver from the chip maker's official driver page first. Without the driver the board won't show up as a COM port.
3. Open Machines (under Setup in the sidebar) and click Add machine.
4. How is it connected? Set Connection to USB / Serial. Firmware is GRBL.
5. Connection settings. Set the Baud rate the controller talks at — most GRBL boards use 115200, so change it only if yours is set differently. Each machine stores its own baud rate.
6. Find your machine. Click Search for machines and GRBL Server lists every board it finds on the host's USB ports (machines you've already added are left out). If yours isn't listed, type its COM port (e.g. COM3) into Port or address and click Look it up.
7. Tick each board you want to add. The Port or address and Serial no. / MAC are filled in for you.
8. Give each one a short, descriptive name (e.g. laser_A) — it's what shows up in jobs and workflows — and a description if you like (e.g. "10 W diode · plywood + acrylic").
9. Click Add selected machines. GRBL Server connects to each board, reads its work area from the controller, and adds it to the Machines page.

Adding a Wi-Fi / Ethernet machine

Most network GRBL controllers are built around the ESP32 chip, which can run as either a Wi-Fi access point or as a client on an existing network. For GRBL Server to find and talk to the machine, the controller must be in STA mode (Station mode) and joined to the same local network as the host computer. Controllers on Ethernet just need to be plugged into the same network.

Switching the controller to STA mode

The exact procedure depends on which firmware your controller runs (FluidNC, GRBL_ESP32, vendor-specific builds), but the shape is the same:

1. Power on the controller and connect to its AP-mode Wi-Fi from a laptop or phone (it usually appears as something like GRBL_ESP32-XXXX or FluidNC).
2. Open the controller's web UI (typically http://192.168.4.1).
3. Find the Wi-Fi / network settings page.
4. Change the mode from AP to STA (or "Station", "Client", depending on the firmware).
5. Enter the SSID and password of your workshop Wi-Fi.
6. Save and reboot the controller. It should now join your network and get an IP from your router.

Check your router's client list (or use a Wi-Fi scanner app) to find the IP it received. A DHCP reservation in the router keeps it stable — although GRBL Server follows a machine to a new address on its own (see Connection status).

Adding the controller to GRBL Server

1. Confirm the controller is reachable from the host: open cmd.exe and run ping <controller-ip>. If ping fails, fix that first — the controller is still in AP mode, on a different network, or blocked by client isolation on the router.
2. On the Machines page, click Add machine.
3. How is it connected? Set Connection to WiFi / Ethernet (WebSocket). Firmware defaults to GRBL-ESP32 (WebUI / FluidNC); pick plain GRBL only if your board runs stock GRBL behind a WebSocket bridge.
4. Connection settings. The WebSocket port defaults to 81 — FluidNC, GRBL-ESP32 and ESP3D boards use port 81 unless you changed it.
5. Find your machine. Click Search for machines and GRBL Server sweeps your local network for controllers, listing each with its IP address and MAC. The search takes a few seconds. If yours isn't listed, type its IP address into Port or address and click Look it up.
6. Tick each controller you want to add, give it a name and description, then click Add selected machines. GRBL Server connects, reads the work area, and adds it.

Network search settings

The network search — and the WebSocket connection itself — is driven by a few values under Settings → WiFi / Ethernet. The defaults suit most home and workshop networks; change them when your setup differs. Edits apply to the next search, connection or job, so there's no need to restart.

Machine settings

Click Settings on a machine's card to open the Machine settings dialog. Its name, description, port or address, work area and maximum power are edited together there, and what you type is checked before it's saved. Changes apply to new jobs; a job already running isn't affected.

Connection status

Each card says whether the machine is connected right now. GRBL Server checks every machine once in the background shortly after it starts, and again each time the Machines page opens; Check again re-runs the check for one machine. A machine that's already running a job is left undisturbed.

Machine controls

Control on a machine's card opens the machine controls. The same controls appear in the Job Station and on workflow runs in Activity, always naming the machine and whether it's connected, with Reconnect beside it.

• Move the head — arrows labelled with their axis (X+, Y−, Z+), a Distance per click from 0.1 to 100 mm, and a Speed in mm/min. Both are remembered.
• Machine commands — Home (run the homing cycle), Unlock (clear an alarm), Status (ask for state and position) and Show settings (list the firmware settings), each with the command it sends underneath.
• Console — what you send and what the machine answers. Type a command and press Enter; ↑ / ↓ go back through earlier commands, and Clear empties it. Commands that may move or stop the machine ask first.

Removing a machine

Remove machine is in the card's menu and asks first. Its jobs stay on the Jobs page, but they can't run until you add the machine again.

What's next

• Create a job on this machine →
• Set up an engraving profile for your material →