stacktoggle has 3 general status LEDs, 3 network interface LEDs, 2 I/O chain LEDs, and 4 local I/O LEDs. 12 LEDs in total.

General status LEDs are located on the bottom left of the top side. From left to right, they are: power, heartbeat, and error LEDs.

Power LED is a green LED. It is on when the stacktoggle is powered on. It is purely hardware controlled.

In normal operation heartbeat LED blinks in heartbeat pattern. It is on most of the time with two short off periods per second. It indicates that system is booted and main IO controlling service is running.

When button on stacktoggle case is pressed, heartbeat LED will change it's blinking pattern to rapid blinking.

Error LED blinks red when there is an important system error. If it is off, that means no important errors are present. When stacktoggle boots it will be red for short period of time until all services are started. Then it will turn off.

In case of update and config reset it blink to indicate these actions. Then LED will stay on until stacktoggle is rebooted.

Errors that will make error LED blink:

• Important system service is not running;
• SD card not found or not formated correctly;
• SN number misconfigured;
• IO modules misconfigured;
• Configuration reset;
• Firmware update.

There are 3 network interface LEDs: 1 Wi-Fi LED and 1 Ethernet LED for each of 2 Ethernet interfaces. These LEDs blink green to indicate that link is up.

I/O chain LEDs are located next to each I/O chain connector (EtherCAT and EtherCAT P). They are green and blink to indicate that I/O chain is connected. These LEDs don't indicate if I/O chain is properly configured.

There are 4 local I/O LEDs, one per each I/O. OUT LEDs indicate that output is ON, and IN LEDs indicate that input is ON.

stacktoggle is equipped with one button on top of the case, next to antenna connectors. Features implemented with the button are:

Press and hold the button for at least 5 seconds until "Wrench" LED starts blinking in red color. The config will be reset to factory defaults. After the reset, the device will reboot.

Press button for 1 second to toggle Wi-Fi access point (hotspot) on and off. You can release button as soon as you see heartbeat LED blinking rapidly.