The Active Machine Detector is a cover added by GregTech 4. It will emit a Redstone signal if the machine it is connected to is performing a process. The strength of the Redstone signal is based on how close the process is to completion; for example, when just started (less than 6.6% complete), it will emit a strength of 1, and when it is almost complete (more than 93.3% complete), it will emit a Redstone signal with a strength of 15.
The Active Machine Detector has four modes. The modes can cycled through by right-clicking the cover with a Screwdriver. The modes are:
Inverted, which will invert the signal emitted.
Ready to work, which will make the cover emit a Redstone signal of 15 when all of the machine's processes are finished.
Not ready to work, which will make the cover emit a Redstone signal of 15 when the machine is processing.
The Active Machine Detector can be applied to any side of a machine by right-clicking a side. It can be removed by right-clicking the cover with a Wrench.