System and method for ensuring continued operation of fan notwithstanding bmc failure

Abstract

A system for maintaining the operation of a cooling fan for a server if that function of a baseboard management controller (BMC) of the server should fail includes the BMC and a control module. The control module is electrically connected to the BMC and the fan, and the control module receives a first signal outputted by the BMC in a cycle and determines the state of the BMC depending on whether the first signal includes a change in level or fails to include a change in level. When an abnormal state of the BMC is determined, the control module outputs a preset pulse width modulation (PWM) signal to the fan to maintain operation of the fan. The present disclosure also provides a fan control method.

What is claimed is: 
     
         1 . A fan control system configured for controlling a fan to operate and comprising:
 a baseboard management controller (BMC);   a control module electrically connected to the BMC and the fan, and configured to receive a first signal outputted by the BMC and determine whether the BMC is in an abnormal state according to the first signal;   wherein when the BMC is in an abnormal state, the control module outputs a preset pulse width modulation (PWM) signal to the fan to keep continuous operation of the fan; and   wherein when the first signal is in an error state continuously within a preset number of cycles, the control module determines the BMC is in the abnormal state.   
     
     
         2 . The fan control system of  claim 1 , wherein when the BMC is in a normal state, the control module control module controls operation of the fan according to the first signal; wherein when the first signal is not in an error state continuously within a preset number of cycles, the control module determines the BMC is in the normal state. 
     
     
         3 . The fan control system of  claim 2 , wherein the control module further comprises a detection unit, a storage unit and a signal selection unit, the detection unit is electrically connected between the BMC and the signal selection unit to detect whether a level state of the first signal is continuously in the error state within the preset number of cycles, to output a second signal to the signal selection unit; the storage unit is electrically connected to the signal selection unit, the storage unit is configured to output the preset PWM signal to the signal selection unit; the BMC is electrically connected to the signal selection unit, the signal selection unit is configured to output the first signal to the signal selection unit; and the signal selection unit is electrically connected to the fan, and the signal selection unit selects to output the first signal or the preset PWM signal to the fan according to the second signal. 
     
     
         4 . The fan control system of  claim 3 , wherein when the detection unit detects the BMC is in the abnormal state according to the first signal, the detection unit outputs the second signal, and the second signal is in a first level state, the signal selection unit outputs the preset PWM signal to the fan according to the second signal; and when the detection unit detects the BMC is in the normal state according to the first signal, the detection unit outputs the second signal, and the second signal is in a second level state, the signal selection unit outputs the first signal to the fan according to the second signal. 
     
     
         5 . The fan control system of  claim 4 , wherein the first signal is a PWM signal. 
     
     
         6 . The fan control system of  claim 1 , wherein the error state is that level state of the first signal remains unchanged. 
     
     
         7 . The fan control system of  claim 1 , wherein the control module further comprises a detection unit, a storage unit, a signal selection unit, a signal processing unit and a PWM signal generation unit, the detection unit is electrically connected between the BMC and the signal selection unit to detect whether a level state of the first signal is continuously in the error state within the preset number of cycles, to output a second signal to the signal selection unit; the signal processing unit is electrically connected between the BMC and the signal selection unit, the signal processing unit is configured to process the first signal to obtain a duty cycle of the first signal in each preset cycle and generate a third signal, and output the third signal to the signal selection unit; the storage unit is electrically connected to the signal selection unit, the storage unit is configured to output a preset adjustment signal to the signal selection unit; the signal selection unit is also electrically connected to the PWM signal generation unit, and the signal selection unit selects to output the third signal or the preset adjustment signal to the PWM signal generation unit according to the second signal; the PWM signal generation unit is electrically connected to the fan, the PWM signal generation unit is configured to generate a target PWM signal according to the third signal and outputting the target PWM signal to the fan, or the PWM signal generation unit is configured to generate the preset PWM signal according to the preset adjustment signal and output the preset PWM signal to the fan. 
     
     
         8 . The fan control system of  claim 7 , wherein when the detection unit detects the BMC is in the abnormal state according to the first signal, the detection unit outputs the second signal, and the second signal is in a first level state, the signal selection unit outputs the preset adjustment signal to the PWM signal generation unit according to the second signal; and when the detection unit detects the BMC is in the normal state according to the first signal, the detection unit outputs the second signal, and the second signal is in a second level state, the signal selection unit outputs the third signal to the PWM signal generation unit according to the second signal. 
     
     
         9 . The fan control system of  claim 8 , wherein the error state is that level state of the first signal remains unchanged, and the first signal is a PWM signal. 
     
     
         10 . The fan control system of  claim 8 , wherein the BMC is electrically connected to the signal processing unit through an integrated circuit bus, and the first signal comprises a duty cycle value, and the error state is loss of the first signal. 
     
     
         11 . A fan control system configured for controlling a fan to operate and comprising:
 a baseboard management controller (BMC);   a control module electrically connected to the BMC and the fan, and configured to receive a first signal outputted by the BMC and determine whether the BMC is in an abnormal state according to the first signal; wherein the error state is that level state of the first signal remains unchanged.   wherein when the BMC is in an abnormal state, the control module outputs a preset pulse width modulation (PWM) signal to the fan to keep continuous operation of the fan; and   wherein when the first signal is in an error state continuously within a preset number of cycles, the control module determines the BMC is in the abnormal state.   
     
     
         12 . The fan control system of  claim 11 , wherein when the BMC is in a normal state, the control module control module controls operation of the fan according to the first signal; wherein when the first signal is not in an error state continuously within a preset number of cycles, the control module determines the BMC is in the normal state. 
     
     
         13 . The fan control system of  claim 12 , wherein the control module further comprises a detection unit, a storage unit and a signal selection unit, the detection unit is electrically connected between the BMC and the signal selection unit to detect whether a level state of the first signal is continuously in the error state within the preset number of cycles, to output a second signal to the signal selection unit; the storage unit is electrically connected to the signal selection unit, the storage unit is configured to output the preset PWM signal to the signal selection unit; the BMC is electrically connected to the signal selection unit, the signal selection unit is configured to output the first signal to the signal selection unit; and the signal selection unit is electrically connected to the fan, and the signal selection unit selects to output the first signal or the preset PWM signal to the fan according to the second signal. 
     
     
         14 . The fan control system of  claim 13 , wherein when the detection unit detects the BMC is in the abnormal state according to the first signal, the detection unit outputs the second signal, and the second signal is in a first level state, the signal selection unit outputs the preset PWM signal to the fan according to the second signal; and when the detection unit detects the BMC is in the normal state according to the first signal, the detection unit outputs the second signal, and the second signal is in a second level state, the signal selection unit outputs the first signal to the fan according to the second signal. 
     
     
         15 . The fan control system of  claim 14 , wherein the first signal is a PWM signal. 
     
     
         16 . The fan control system of  claim 11 , wherein the control module further comprises a detection unit, a storage unit, a signal selection unit, a signal processing unit and a PWM signal generation unit, the detection unit is electrically connected between the BMC and the signal selection unit to detect whether a level state of the first signal is continuously in the error state within the preset number of cycles, to output a second signal to the signal selection unit; the signal processing unit is electrically connected between the BMC and the signal selection unit, the signal processing unit is configured to process the first signal to obtain a duty cycle of the first signal in each preset cycle and generate a third signal, and output the third signal to the signal selection unit; the storage unit is electrically connected to the signal selection unit, the storage unit is configured to output a preset adjustment signal to the signal selection unit; the signal selection unit is also electrically connected to the PWM signal generation unit, and the signal selection unit selects to output the third signal or the preset adjustment signal to the PWM signal generation unit according to the second signal; the PWM signal generation unit is electrically connected to the fan, the PWM signal generation unit is configured to generate a target PWM signal according to the third signal and outputting the target PWM signal to the fan, or the PWM signal generation unit is configured to generate the preset PWM signal according to the preset adjustment signal and output the preset PWM signal to the fan. 
     
     
         17 . The fan control system of  claim 16 , wherein when the detection unit detects the BMC is in the abnormal state according to the first signal, the detection unit outputs the second signal, and the second signal is in a first level state, the signal selection unit outputs the preset adjustment signal to the PWM signal generation unit according to the second signal; and when the detection unit detects the BMC is in the normal state according to the first signal, the detection unit outputs the second signal, and the second signal is in a second level state, the signal selection unit outputs the third signal to the PWM signal generation unit according to the second signal. 
     
     
         18 . The fan control system of  claim 17 , wherein the first signal is a PWM signal. 
     
     
         19 . The fan control system of  claim 17 , wherein the BMC is electrically connected to the signal processing unit through an integrated circuit bus, and the first signal comprises a duty cycle value, and the error state is loss of the first signal. 
     
     
         20 . A fan control method configured for controlling a fan to operate and comprising:
 receiving a first signal input by a baseboard management controller (BMC);   determining whether the first signal is in an error state continuously within a preset number of cycles;   outputting a preset pulse width modulation (PWM) signal to the fan;   controlling operation of the fan according to the first signal.