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8.0 LEDs [T-Series Datasheet]

STATUS - The Green LED

The STATUS LED indicates when the T-series device is performing autonomous tasks, such as running an on-board Lua script or streaming. The STATUS LED will blink according to the following rules:

  • Continuously while stream is running.

  • Once when a Lua script accesses a Modbus register.

  • Twice every 2 seconds when the T8 is in recovery mode.

  • In conjunction with the COMM LED. See the Combined LED Activity section.

COMM - The Yellow LED

The COMM LED's primary purpose is to indicate packet transfer. The COMM LED will blink according to the following rules:

  • Once for each packet transferred. At high packet transfer rates the LED will blink at 10Hz, even if more than 10 packets are being processed per second.

  • Continuously when stream mode is running.

  • A few times after successfully connecting to a USB host.

  • In conjunction with the STATUS LED. See the Combined LED Activity section.

Normal Behavior

Here are 3 examples of normal LED behavior.  For troubleshooting it is useful to compare these examples to what you see on your device.


  1. Both LEDs blink rapidly for about 1 second.

  2. COMM solid off and STATUS solid on.

  3. If USB enumerates, COMM blinks a few times and then stays solid on.


Both LEDs solid on.  No blinking

While Viewing Kipling's Dashboard

Green LED solid on.  Orange LED also solid on but with a quick double-blink once per second.

Combined LED Activity

  • When the LEDs blink together, the T-series device is computing checksums.

  • When the LEDs are alternating, the T-series device is copying a firmware image.


If LED behavior is not normal, please see USB Communication Failure.

LED Configuration

The LED mode can be set using the following registers:

When POWER_LED is set to manual mode, the LEDs can be turned on and off using the following registers:

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