TWI479085B - Fan rotational speed control system and method for controlling rotation speed of fan - Google Patents

Description

Fan speed control system and method for controlling fan speed

The invention relates to a control system and a control method, in particular to a fan speed control system and a method for controlling the fan speed.

With the advancement of technology, current server systems often include a large number of electronic computing devices that generate a large amount of thermal energy during operation. Without proper heat dissipation devices, electronic computing devices can easily crash or become damaged. .

Therefore, the current server system is provided with a plurality of thermal sensors, a Baseboard Management Controller (BMC) and a plurality of cooling fans to control the temperature inside the server system. Briefly, the temperature sensing device returns the detected temperature to the substrate management controller, and the rear substrate management controller adjusts the speed of the individual fans according to the temperature for effective heat dissipation.

However, this design is not perfect; the main reason is that the embedded system of the baseboard management controller may have unexpected errors after a period of execution. When this error occurs, if the speed control pin of the system cooling fan happens to be at the full high level, all fans will rotate at full speed. In this case, although the system will not be damaged by overheating, not all fans need to run at full speed to dissipate heat, and the high power consumption required at this time will cause unnecessary waste. Or, when the above error occurs, if the speed control pin of the system cooling fan is just in full A low-low state will cause all fans to stop, which will greatly increase the chances of damage to the system due to excessive temperature. The above-mentioned fans are active high or active low and are ordered according to the individual circuit design.

It can be seen that there is a need in the related art for a novel heat dissipation method capable of effectively controlling the temperature inside the server system; more preferably, the heat dissipation method can effectively be used even when an error occurs in the substrate management controller. Control the speed of individual fans to avoid damage to the hardware.

It is an object of the present invention to provide a fan speed control system and a method for controlling the speed of the fan to effectively control the temperature inside the server system.

In order to achieve the above object, a technical aspect of the present invention relates to a fan speed control system for controlling at least one fan. The aforementioned fan speed control system includes a baseboard management controller, a programmable logic device, and a switching circuit. The circuit management controller is electrically coupled to the fan, the programmable logic device is electrically coupled to the substrate management controller, and the switching circuit is electrically coupled to the fan, the substrate management controller, and the programmable Logic device.

In operation, the substrate management controller outputs a fan pulse signal and a heartbeat bit, and the programmable logic device receives the heartbeat bit, and determines whether the substrate management controller has an error according to the heartbeat bit, and is used for the substrate management controller. Generate and output switching signals and take over pulse signals when an error occurs number. The switching circuit receives and outputs the fan pulse signal when the substrate management controller does not generate an error, and receives the switching signal and the pulse signal when the substrate management controller generates an error to output the pulse signal.

According to an embodiment of the invention, the substrate management controller outputs a start signal to the programmable logic device after being enabled.

According to another embodiment of the present invention, the substrate management controller outputs a current rotational speed signal of the fan to the programmable logic device.

According to still another embodiment of the present invention, the programmable logic device includes a temporary register, a control module, and at least one pulse wave generating module. The control module is electrically coupled to the substrate management controller and the switching circuit, and the pulse generating modules are electrically coupled to the control module. The register system stores a fan tachometer, and the control module receives the heartbeat bit and the current speed signal to determine whether the substrate management controller has an error according to the heartbeat bit, and outputs a switching signal when determining that the substrate management controller has an error and A control signal is generated and output according to the fan tachometer and the current speed signal. The pulse wave generating modules receive and output pulse signals according to the control signals. In addition, when the control module determines that the substrate management controller returns to normal, it outputs a reply signal to the switching circuit, so that the switching circuit receives and outputs the fan pulse signal.

According to still another embodiment of the present invention, the foregoing programmable logic device further includes a time control module and a switch unit. The time control module is electrically coupled to the control module, and the switch unit is electrically coupled to the pulse generation module and the time control module. The time control module starts counting when receiving the control signal, and generates and outputs a conduction when the preset time exceeds a preset time. Signal. The switch unit receives the pilot signal and the pulse signal for receiving the pulse signal according to the communication number.

In order to achieve the above object, another aspect of the present invention relates to a method for controlling a fan speed, which is applicable to a server, which includes a substrate management controller, a programmable logic device, a switching circuit, and a fan. The method includes the following steps: the substrate management controller generates and outputs a fan pulse signal and a heartbeat bit; the programmable logic device receives the heartbeat bit, and determines whether the substrate management controller has an error according to the heartbeat bit; The logic device determines that an error occurs in the substrate management controller, generates and outputs a switching signal and a pulse signal; and the switching circuit receives the switching signal and the pulse signal, and outputs a pulse signal; wherein, when the substrate management control When no error occurs, the switching circuit receives and outputs the fan pulse signal.

According to an embodiment of the invention, the method for controlling the fan speed further includes: the substrate management controller outputs a start signal after being enabled; and the substrate management controller outputs a current speed signal of the fan.

According to another embodiment of the present invention, when the programmable logic device determines that an error occurs in the substrate management controller, the step of generating and outputting the pulse signal includes: receiving the current speed signal; When it is determined that the substrate management controller has an error, the built-in fan tachometer is read; the control signal is generated according to the fan tachometer and the current speed signal; and the pulse signal is generated according to the control signal generation and output.

According to still another embodiment of the present invention, when the programmable logic device determines that the substrate management controller has an error, the step of generating and outputting the pulse signal is further included: when the control signal is received, counting starts, and determining whether the error is exceeded. The preset time; when it is judged that the preset time is exceeded, the communication number is generated; and the pulse signal is output according to the communication number.

According to still another embodiment of the present invention, the method for controlling the fan speed further includes: when it is determined that the substrate management controller returns to normal, the programmable logic device outputs a reply signal, so that the switching circuit receives and outputs the fan pulse. Signal.

Therefore, according to the technical content of the present invention, an embodiment of the present invention provides a fan speed control system and a method for controlling the fan speed, thereby effectively controlling the temperature inside the server system, and whether the substrate management controller has an error or not The fan speed can be properly controlled to avoid damage to the hardware.

In order to make the description of the present disclosure more detailed and complete, reference is made to the accompanying drawings and the various embodiments described below. The same or similar components. However, the embodiments provided are not intended to limit the scope of the invention, and the description of the operation of the structure is not intended to limit the order of its execution, and any device that is recombined by the components produces equal devices. The scope covered by the invention.

The drawings are for illustrative purposes only and are not drawn to the original dimensions. On the other hand, well-known elements and steps are not described in the embodiments to avoid unnecessarily limiting the invention.

1 is a circuit block diagram of a fan speed control system according to an embodiment of the invention. The fan speed control system is configured to control at least one fan, and includes a Baseboard Management Controller (BMC) 110, a Complex Programmable Logic Device (CPLD) 120, and a plurality of switching circuits 130-180. The circuit management controller 110 is electrically coupled to the fan, the programmable logic device 120 is electrically coupled to the substrate management controller 110, and the switching circuit 130 is electrically coupled to the fan and the substrate management controller. 110 and programmable logic device 120.

Further, taking the switching circuit 130 as an example, the switching circuit 130 includes an input end and an output end 134, and the input end of the switching circuit 130 includes a first input port 131 and a second input port 132. The first input port 131 is electrically coupled to the substrate management controller 110, and the second input port 132 is electrically coupled to the programmable logic device 120. The output terminal 134 is electrically coupled to the output terminal 134. Fan 135.

In operation, the input of the switching circuit 130 can be switched between the first input port 131 and the second input port 132. When switching circuit 130 When the input end is switched to the first input port 131, the substrate management controller 110 outputs a control signal to the switching circuit 130. The control signal is output to the fan 135 via the switching circuit 130 and through the output terminal 134 of the switching circuit 130. The fan 135 Receive and determine the speed based on this control signal.

In addition, when the input end of the switching circuit 130 is switched to the second input port 132, the programmable logic device 120 outputs a control signal to the switching circuit 130, and the control signal passes through the switching circuit 130 and passes through the output terminal 134 of the switching circuit 130. Output to the fan 135, the fan 135 receives and determines its rotational speed based on the control signal. When it is necessary to switch the input end of the switching circuit 130 to the first input port 131, and when it is necessary to switch the input end of the switching circuit 130 to the second input port 132, that is, the switching mechanism of the fan speed control system will be Detailed in the text.

It should be noted that the structures and functions of the switching circuits 140, 150, 160, 170, and 180 are similar to those of the switching circuit 130. For brevity of the description of the present invention, details are not described herein. However, the configuration shown in FIG. 1 is not intended to limit the present invention. Those skilled in the art can configure the switching circuits 130-180 and the fans 135, 145, 155, 165, 175, 185 according to actual needs.

In order to make the switching mechanism of the fan speed control system easier to understand, first, the initial state of the fan speed control system is introduced. In the initial state, the input terminal of the switching circuit 130 is switched to the first input port 131, and the substrate management controller 110 controls the fan 135 through the switching circuit 130. However, after the substrate management controller 110 performs a period of time, an unexpected error may occur. At this time, another electronic component is needed to assist the substrate management controller 110 to control the fan 135, and an appropriate one is needed. The switching mechanism switches the control of the fan rotational speed control system from the baseboard management controller 110 to another electronic component when an error occurs in the baseboard management controller 110.

The other electronic component can be implemented by the programmable logic device 120 to assist the substrate management controller 110 to control the fan 135 by the programmable logic device 120 when an error occurs in the substrate management controller 110. In addition, the implementation of the switching mechanism is as follows. First, the substrate management controller 110 outputs a fan pulse signal and a heart bit or heart beat to the programmable logic device 120. The programmable logic device 120 is provided by the programmable logic device 120. Receiving the heartbeat bit, and determining whether the substrate management controller 110 has an error according to the heartbeat bit. Then, when the programmable logic device 120 determines that the substrate management controller 110 has an error, generating and outputting the switching signal and the receiving pulse wave The signal is switched to the switching circuit 130. At this time, the control of the fan speed control system is switched by the baseboard management controller 110 to the programmable logic unit 120.

In detail, when the programmable logic device 120 continues to receive the heartbeat bit output by the substrate management controller 110, the programmable logic device 120 determines that the substrate management controller 110 has not generated an error, and inputs the switching circuit 130. The input terminal of the switching circuit 130 is still electrically coupled to the substrate management controller 110, and the switching pulse signal is received and output by the switching circuit 130 to the fan 135. The fan 135 adjusts the rotation speed according to the fan pulse signal. . Here, the control method of the switching circuits 140-180 is similar to the switching circuit 130. Similarly, when the programmable logic device 120 determines that the substrate management controller 110 has not generated an error, the switching circuit The input ends of 130~180 are not switched, and the switching pulse circuit 130 receives and outputs the fan pulse signal to the fans 135~185, and the fan 135 adjusts the rotation speed according to the fan pulse signal.

Moreover, when the programmable logic device 120 does not receive the heartbeat bit output by the substrate management controller 110, the programmable logic device 120 determines that the substrate management controller 110 has an error, and the programmable logic device 120 The switching signal is output to the switching circuit 130. The input end of the switching circuit 130 receives the switching signal to be switched from the first input port 131 to the second input port 132. At the same time, the programmable logic device 120 outputs the pulse signal, and the switching circuit is used. After receiving 130, the output receives the pulse signal to the fan 135, and the fan 135 adjusts the rotation speed according to the pulse signal. Here, the control method of the switching circuits 140-180 is similar to the switching circuit 130. Similarly, when the programmable logic device 120 determines that the substrate management controller 110 has an error, the input terminals of the switching circuits 130-180 receive the switching. The signal is switched to the second input port 132, 142, 152, 162, 172, 182 by the first input port 131, 141, 151, 161, 171, 181, and the pulse signal is taken over by the programmable logic device 120. After receiving by the switching circuits 130-180, the output pulse signals are sent to the fans 135~185, and the fans 135~185 adjust the rotation speed according to the pulse signals.

In this way, the fan speed control system uses the above switching mechanism. When the substrate management controller 110 is operating normally, the substrate management controller 110 transmits the fan pulse signal to the fans 135-185 through the switching circuits 130-180 to control the fan 135. The rotation speed of ~185, and when the substrate management controller 110 has an error, the input end of the switching circuit 130-180 is An input port 131-181 is switched to the second input port 132-182, and the control of the fan speed control system is switched from the substrate management controller 110 to the programmable logic device 120, and the programmable logic device 120 transmits the switching circuit 130. ~180 transmits the pulse signal to control the speed of the fan 135~185. Therefore, regardless of whether the substrate management controller 110 has an error, the fan speed control system can correctly control the rotational speed of the fans 130-180.

In an embodiment, since the state of the substrate management controller 110 is not yet stable, the programmable logic device 120 does not determine whether the substrate management controller 110 is first when the substrate management controller 110 is turned on. In the error, after the substrate management controller 110 is stabilized, for example, after the substrate management controller is enabled, the substrate management controller 110 outputs a start signal to the programmable logic device 120. At this time, the programmable logic device 120 receives After the start signal, the heartbeat bit outputted by the substrate management controller 110 is detected and detected to determine whether the substrate management controller 110 has an error.

In implementing embodiments of the present invention, the programmable logic device 120 can include a register 121 for storing a fan tachometer, and the fan tachometer records individual speeds of the fans 135-185. In general, the substrate management controller 110 can be used to monitor the operating conditions of the servers to determine the rotational speed of the fans 135-185, so that the fans 135-185 can efficiently dissipate the servers. However, the programmable logic device 120 cannot monitor the operation of the server. If the programmable logic device 120 controls the speed of the fans 135-185, the server cannot be efficiently dissipated.

Therefore, when the substrate management controller 110 is operating normally, the substrate management The controller 110 outputs the current rotational speed signals of the fans 135-185 to the programmable logic device 120 according to the operating conditions of the server to set the individual rotational speeds of the fans 135-185 recorded by the fan tachometer in the temporary storage unit 121. When the substrate management controller 110 generates an error and the fans 135-185 are controlled by the programmable logic device 120, the programmable logic device 120 can be based on the fan 135-185 of the fan tachometer preset by the substrate management controller 110. The individual rotational speeds are used to control the fans 135~185. In this way, the programmable logic device 120 can also efficiently dissipate the server according to a preset fan tachometer.

In another embodiment, in practice, the programmable logic device 120 further includes a control module 122 and at least one pulse wave generating module (for example, one of Fan1~Fan6). The control module 122 is electrically coupled to the substrate management controller 110 and the switching circuits 130-180. The pulse wave generating modules Fan1~Fan6 are electrically coupled between the control module 122 and the switching circuit. However, the present invention is not limited to the electronic component arrangement mode shown in Fig. 1, and the remaining arrangement of the electronic component shown in Fig. 1 is within the scope of the invention without departing from the spirit of the invention.

In operation, the control module 122 receives the heartbeat bit and the current speed signal from the substrate management controller 110 to determine whether the substrate management controller 110 has an error according to the heartbeat bit, and when determining that the substrate management controller 110 has an error. The output switching signal is generated and the control signal is generated and output according to the fan tachometer and the current speed signal. The pulse wave generating module Fan1~Fan6 receives and generates a pulse signal according to the control signal generation and output. When the control module 122 determines that the substrate management controller 110 is back to normal, it outputs back The signal is transmitted to the switching circuits 130-180 so that the switching circuits 130-180 receive and output the fan pulse signals to the fans 135-185, and the fans 135-185 adjust the rotation speed according to the fan pulse signals.

In another embodiment, the programmable logic device 120 may have a misjudgment that the substrate management controller 110 has an error. Therefore, when the programmable logic device 120 determines that the substrate management controller 110 has an error, It is not appropriate to directly transfer the master control of the fan speed control system from the baseboard management controller 110 to the programmable logic device 120.

To prevent miscalculation of the programmable logic device 120, the fan speed control system of the embodiment of the present invention further includes a time control module 123 and a switch unit (eg, switch units 124-129). When the programmable logic device 120 determines the baseboard management controller When the error occurs, the time control module 123 receives the control signal output by the control module 122, and the time control module 123 starts counting when receiving the control signal, and generates and outputs the communication number when the preset time is exceeded. For example, the preset time is 10 seconds. When the time control module 123 starts counting for more than 10 seconds when receiving the control signal, it indicates that the substrate management controller 110 does not have an error, instead of being misjudged by the programmable logic device 120, the control is performed. The module 122 outputs a switching signal at this time point, so that the substrate management controller 110 can be prevented from returning to normal within a preset time, and the fans 135-185 have been transferred to the state controlled by the programmable logic device 120. .

In addition, the control module 122 can also output (whether or not the preset time is exceeded) when it is determined that the substrate management controller 110 has an error, because the control module 122 will be determined as long as it is determined that the substrate management controller 110 is normal. A reply signal is sent to the switching circuits 130-180, so that the switching circuits 130-180 receive and output the fan pulse signals to the fans 135-185.

In addition, the switch units 124-129 receive the pilot signal and the pulse signal for receiving the pulse signal to the fans 135-185 according to the communication number. Further, in implementing the present invention, the switches 124-129 can be transistors, gates, or other electronic components that can achieve switching operations.

In yet another embodiment, the fan tachometer includes a duty cycle of the fans 135-185, as shown in the following table:

When the programmable logic device 120 determines that an error occurs in the substrate management controller 110, the programmable logic device 120 outputs a switching signal to the switching circuits 130-180, and the input terminals of the switching circuits 130-180 are switched according to the switching signal. The stylized logic device 120 controls the individual rotational speeds of each of the fans 135-185 by the programmable logic device 120 according to the fan tachometer shown in Table 1 and through the switching circuits 130-180.

FIG. 2 is a schematic flow chart of a method 200 for controlling a fan speed according to another embodiment of the present invention. The server is applicable to a server, and the server includes a substrate management controller, a programmable logic device, a switching circuit, and a fan. As shown in the figure, the foregoing method includes the following steps: the substrate management controller outputs a start signal after being enabled (step 210); the substrate management controller outputs a current speed signal of the fan (step 220); and the substrate management controller generates and outputs a fan pulse signal and a heartbeat bit (step 230); the programmable logic device receives the heartbeat bit and determines whether the baseboard management controller has an error based on the heartbeat bit (step 240); when the programmable logic device determines When the substrate management controller generates an error, the switching signal is generated and outputted (step 250); the switching circuit receives the switching signal and the pulse signal, and outputs the pulse signal (step 260); when the substrate management control When no error occurs, the switching circuit receives and outputs a fan pulse signal (step 270).

In order to make the method 200 for controlling the fan speed in the embodiment of the present invention easier to understand, the above-described flow will be exemplarily illustrated together with FIG. 1 . First, steps 210 and 240 are for preventing the situation that the state of the programmable logic device 120 may be misjudged when the substrate management controller 110 is just turned on, and the details may be as follows. Since the state of the substrate management controller 110 is not yet stable when the substrate management controller 110 is turned on, the programmable logic device 120 does not judge whether the substrate management controller 110 is erroneous when the substrate management controller 110 is just turned on. After the substrate management controller 110 is enabled as shown in step 210, the start signal is outputted to the programmable logic device 120. Here, the step 240 adds a limit, that is, the program. After receiving the start signal, the logic device 120 starts to receive the heartbeat bit output by the substrate management controller 110, and determines whether the substrate management controller 110 has an error according to the heartbeat bit. However, the present invention is not limited thereto, and another substrate management controller 110 and the programmable logic device 120 cooperate with each other as shown in steps 230 and 240.

In step 230, the substrate management controller 110 generates and outputs a fan pulse signal and a heartbeat bit to the programmable logic device 120. Next, in step 240, the programmable logic device 120 can directly receive the heartbeat bit without receiving the start signal, and determine whether the substrate management controller 110 has an error according to the heartbeat bit.

In addition, the step 220 is intended to: when the baseboard management controller 110 is operating normally, the baseboard management controller 110 sets the fan speed in the programmable logic device 120 by outputting the current rotational speed signal of the fan according to the operating condition of the server. The individual rotational speeds of the fans 135-185 recorded in the table, when the substrate management controller 110 has an error, and the programmable logic device 120 controls the fans 135-185, the programmable logic device 120 can be based on the substrate management controller 110. The preset speeds of the fans 135~185 of the fan tachometer are used to control the fans 135~185. Thus, the programmable logic device 120 can also be efficiently operated according to a preset fan tachometer. Ground the server to dissipate heat.

When the programmable logic device 120 determines that an error has occurred in the baseboard management controller 110, as shown in step 250, the programmable logic device 120 generates and outputs a switching signal and a takeover pulse signal. Then, the switching circuit receives the switching signal and the pulse signal as shown in step 260, and outputs the takeover. Pulse signal to fan 135~185, fan 135~185 adjust its speed according to the pulse signal. When step 260 is performed, step 240 is performed. In addition, when the programmable logic device 120 determines that the substrate management controller 110 is back to normal, the programmable logic device 120 outputs a reply signal to cause the switching circuits 130-180 to receive and output the fan pulse signal.

Moreover, after the step 240, when the programmable logic device 120 determines that the substrate management controller 110 has not generated an error, as shown in step 270, the switching circuit receives and outputs the fan pulse signal to the fans 135-185. Fans 135~185 adjust their speed according to the fan pulse signal. After step 270 is performed, step 240 is performed to continue monitoring the substrate management controller 110 by the programmable logic device 120.

In an embodiment, the step 250 includes: receiving the current speed signal; when determining that the substrate management controller has an error, reading the built-in fan speed table; generating a control signal according to the fan speed meter and the current speed signal; Control signal generation and output take over the pulse signal. When the step is implemented, the control module 122 receives the heartbeat bit and the current speed signal from the substrate management controller 110 to determine whether the substrate management controller 110 has an error according to the heartbeat bit, and determines that the substrate management controller 110 is generated. When the error occurs, read the built-in fan tachometer. Then, the control module 122 generates and outputs a control signal according to the fan tachometer and the current rotational speed signal. The pulse wave generating module Fan1~Fan6 receives and generates a pulse signal according to the control signal generation and output.

In another embodiment, step 250 includes: counting when the control signal is received, and determining whether the preset time is exceeded; When the time is set, the pilot number is generated; and the pulse signal is output according to the communication number. This step is used to prevent miscalculation of the programmable logic device 120, the mechanism of which is as follows. The programmable logic device 120 may have a misjudgment to the substrate management controller 110. Therefore, when the programmable logic device 120 determines that the substrate management controller 110 has an error, if the fan speed control system is directly controlled, It is not appropriate for the base management controller 110 to hand over to the programmable logic device 120.

In order to prevent the erroneous determination of the programmable logic device 120, when the programmable logic device 120 determines that the substrate management controller 110 has an error, the time control module 123 receives the control signal output by the control module 122, and the time control module 123 When the control signal is received, the counting starts, and when it is determined that the preset time is exceeded, the communication number is generated and output. For example, the preset time is 10 seconds. When the time control module 123 starts counting for more than 10 seconds when receiving the control signal, it indicates that the substrate management controller 110 does not generate an error, instead of being misjudged by the programmable logic device 120. When the switch units 124~129 output the pulse signal to the fans 135~185 according to the communication number, the fans 135~185 adjust the rotation speed according to the pulse signal.

The method for controlling the fan speed as described above can be performed by software, hardware, and/or carcass. For example, if the execution speed and accuracy are the primary considerations, the hardware and/or the carcass may be mainly used; if the design flexibility is the primary consideration, the software may be mainly used; or At the same time, the software, hardware and carcass work together. It should be understood that the above examples are not intended to limit the present invention, and are not intended to limit the present invention. Those skilled in the art will need to design elastically at that time.

Moreover, those skilled in the art can understand that the steps in the method for controlling the fan speed are named according to the functions they perform, only to make the technology of the present invention more obvious and understandable, and not to limit These steps. It is still an embodiment of the present disclosure to integrate the steps into the same step or to split into multiple steps, or to replace any of the steps into another step.

It will be apparent from the above-described embodiments of the present invention that the application of the present invention has the following advantages. The embodiment of the invention provides a fan speed control system and a method for controlling the fan speed, thereby effectively controlling the temperature inside the server system, and the fan speed can be correctly controlled regardless of whether the substrate management controller has an error. To avoid damage to the hardware.

Although the present invention has been disclosed in the above embodiments, it is not intended to limit the present invention, and the present invention can be modified and modified without departing from the spirit and scope of the present invention. The scope is subject to the definition of the scope of the patent application attached.

110‧‧‧Baseboard Management Controller

120‧‧‧Programmable logic device

121‧‧‧ register

122‧‧‧Control Module

123‧‧‧Time Control Module

124, 125, 126, 127, 128, 129‧‧‧ switch units

130, 140, 150, 160, 170, 180‧‧‧ switching circuits

131, 141, 151, 161, 171, 181‧‧‧ first input port

132, 142, 152, 162, 172, 182‧‧‧ second input port

134, 144, 154, 164, 174, 184‧‧ ‧ outputs

135, 145, 155, 165, 175, 185‧ ‧ fans

Fan 1~6‧‧‧ Pulse Generation Module

200‧‧‧Method for controlling fan speed

210~270‧‧‧Steps

The above and other objects, features, advantages and embodiments of the present invention will become more <RTIgt; </ RTI> <RTIgt; </ RTI> <RTIgt; </ RTI> <RTIgt; Figure.

2 is a flow chart showing a method for controlling a fan speed according to another embodiment of the present invention.

110‧‧‧Baseboard Management Controller

120‧‧‧Programmable logic device

121‧‧‧ register

122‧‧‧Control Module

123‧‧‧Time Control Module

124, 125, 126, 127, 128, 129‧‧‧ switch units

130, 140, 150, 160, 170, 180‧‧‧ switching circuits

131, 141, 151, 161, 171, 181‧‧‧ first input port

132, 142, 152, 162, 172, 182‧‧‧ second input port

134, 144, 154, 164, 174, 184‧‧ ‧ outputs

135, 145, 155, 165, 175, 185‧ ‧ fans

Fan 1~6‧‧‧ Pulse Generation Module

Claims (10)

A fan speed control system for controlling at least one fan, the fan speed control system comprising: a substrate management controller electrically coupled to the fans, the substrate management controller outputs a fan pulse signal and a heartbeat position a programmable logic device electrically coupled to the baseboard management controller, the programmable logic device receiving the heartbeat bit, and determining whether the baseboard management controller has an error according to the heartbeat bit, And generating, by the substrate management controller, a switching signal and a pulse signal; and a switching circuit electrically coupled to the fan, the substrate management controller, and the programmable logic device; The switching circuit receives and outputs the fan pulse signal when the substrate management controller does not generate an error, and receives the switching signal and the take-up pulse wave signal when the substrate management controller generates an error to output the takeover Pulse signal. The fan speed control system of claim 1, wherein the baseboard management controller outputs a start signal to the programmable logic device when enabled. The fan speed control system of claim 1, wherein the baseboard management controller outputs a current speed signal of the fan to the programmable logic device. The fan speed control system of claim 3, wherein the programmable logic device comprises: a register, wherein the fan tachometer is stored; a control module electrically coupled to the baseboard management controller and the switching circuit, and receiving the heartbeat bit and the current rotational speed signal to determine whether the baseboard management controller has an error according to the heartbeat bit Outputting the switching signal when determining that the substrate management controller is in error, and generating and outputting a control signal according to the current speed signal and the current speed signal; and at least one pulse wave generating module electrically coupled to the control mode And receiving and outputting the take-up pulse signal according to the control signal; wherein, when the control module determines that the baseboard management controller returns to normal, outputting a reply signal to the switching circuit to enable the The switching circuit receives and outputs the fan pulse signal. The fan speed control system of claim 4, wherein the programmable logic device further comprises: a time control module electrically coupled to the control module, and starting to count when receiving the control signal, Generating and outputting a pilot communication number when a predetermined time is exceeded; and a switch unit electrically coupled to the pulse wave generating module and the time control module, and receiving the pilot communication number and the pulse signal of the takeover, The output pulse signal is output according to the communication number. A method for controlling a fan speed is applied to a server, the server includes a substrate management controller, a programmable logic device, a switching circuit and a fan, and the method for controlling the fan speed includes: The substrate management controller generates and outputs a fan pulse signal and a heartbeat bit; the programmable logic device receives the heartbeat bit and according to the heart The jump bit determines whether the substrate management controller has an error; when the programmable logic device determines that the substrate management controller has an error, generates and outputs a switching signal and a take-over pulse wave signal; and the switching circuit receives The switching signal and the pulse signal are received, and the pulse signal is outputted; wherein, when the substrate management controller does not generate an error, the switching circuit receives and outputs the fan pulse signal. The method for controlling the fan speed as described in claim 6, further comprising: the baseboard management controller outputs a start signal after being enabled; and the baseboard management controller outputs a current speed signal of the fan. The method for controlling the fan speed as described in claim 7, wherein when the programmable logic device determines that the substrate management controller has an error, the step of generating and outputting the take-up pulse signal includes: receiving the current a speed signal; when it is determined that the substrate management controller has an error, reading a built-in fan tachometer; generating a control signal according to the fan tachometer and the current speed signal; and generating and outputting the control signal according to the control signal Take over the pulse signal. The method of claim 8, wherein the step of generating and outputting the pulse signal is further included when the programmable logic device determines that the substrate management controller has an error: When the control signal is received, the counting starts, and it is determined whether the preset time is exceeded. When it is determined that the preset time is exceeded, a guiding communication number is generated; and the receiving pulse signal is output according to the guiding communication number. The method for controlling the fan speed as described in claim 6, further comprising: when determining that the baseboard management controller returns to normal, the programmable logic device outputs a reply signal to enable the switching circuit to receive and output The fan pulse signal.