Other Parts Discussed in Thread: AMC6821
Currently I am programming a driver for the Intelligent Temperature Monitor and PWM Fan Controller AMC6821-Q1. This device is connected to a fan with two wires, TACH and PWM-OUT.
The AMC6821 is connected via the I2C bus to a processor core of the Xilinx UltraScale Plus FPGA which is also on the PCB. With this I can write and read back the registers values.
The problem is that the fan only runs for a short time with maximum rotation after the power supply is switched on, but then switches off, before I control ist with the software.
Reading the temperature values works. However, the value of the tachometer register is always 0xFFFF. For example, the local temperature is 25.75 degrees, the remote temperature is 40.25 degrees. But in the TACH-DATA register is always the value 0xFFFF.
We want to use the
Maximum Fast-Speed Calculated Control Mode
but the phenomenon is also present in the other modes:
Software DCY Control Mode
Software RPM Control Mode
Auto Temperature Fan Mode
I am very grateful for the crucial tip to solve this problem.
Best regards
Thomas
