Communicates with the information handling system air mover using the enhanced tachometer data signal protocol via variable read and write commands

Abstract

An information handling system may include: an air mover configured to drive an air flow; and a processing component communicatively coupled to the air mover for controlling the operation of the air mover via: a first line configured to communicate an analog air mover speed command from the processing component to the air mover for controlling the speed of the air mover; and a second line configured to communicate analog tachometer information from the air mover to the processing component. At least one of the air mover and the processing component may be configured to initiate a serial digital communication mode via the first line and the second line. The air mover and the processing component may be configured to communicate information to each other via the first line and the second line during the serial digital communication mode according to a digital communication protocol.

Description

Technical Field

[0001] The present invention relates generally to the field of information handling system cooling fan operation, and more particularly, to a system and method for communicating with an information handling system cooling fan using a communication upgrade module. Background Art

[0002] As the value and use of information continue to increase, individuals and enterprises seek other ways to process and store information. One option available to users is an information processing system. An information processing system usually processes, compiles, stores and / or communicates information or data for a business, individual or other purpose, thereby allowing users to take advantage of the value of information. Because technology and information processing needs and requirements are different between different users or applications, information processing systems may also be different in the following aspects: what information to process, how to process information, how much information to process, store or communicate, and how quickly and efficiently to process, store or communicate information. The changes in information processing systems allow information processing systems to be general or configured for specific users or specific purposes (such as financial transaction processing, flight reservations, enterprise data storage or global communications). In addition, an information processing system may include various hardware and software components that can be configured to process, store and communicate information, and may include one or more computer systems, data storage systems and networking systems.

[0003] As the clock speeds and power consumption of processors, graphics cards, random access memory (RAM), and other components in information handling systems have increased, the amount of heat generated by such components as a side effect of normal operation has also increased. Typically, the temperature of these components needs to be maintained within a reasonable range to prevent overheating, instability, malfunction, and damage that can shorten the useful life of the components. Therefore, air movers (e.g., cooling fans and blowers) are often used in information handling systems to cool the information handling system and its components.

[0004] As information handling systems have grown in importance to businesses and individuals, reliability has become an increasingly important factor in system design and selection. An increasing number of components include monitoring subsystems that detect and report abnormal operation, so that the risk of overall system failure and downtime is reduced. If failure of a component is detected or anticipated, the component is typically replaced as soon as practicable to avoid unnecessary downtime. Often, relatively inexpensive and unsophisticated components prove critical to the operation of an information handling system. For example, if one or more of the air movers of an information handling system fails, the system will quickly overheat, causing an automatic shutdown of the safety system that detects the overheating, or worse, resulting in catastrophic failure of one or more components.

[0005] Information handling system air movers typically operate at variable speeds to provide variable amounts of cooling airflow. Operating the air mover at a reduced speed helps reduce noise and power consumption, where higher speeds are not needed to cool information handling system components. Typically, a feedback system is used to control the air mover speed so that the speed increases with increasing operating temperature and decreases with decreasing operating temperature. One type of air mover feedback system operates in a three-wire configuration: a power line, a ground line, and a tachometer line. The tachometer line provides air mover speed measurements to the thermal control system of the information handling system. The thermal control system can adjust the air mover speed by adjusting the power applied to the power line in response to changes in operating temperature. Another type of air mover feedback system operates in a four-wire configuration: a power line, a ground line, a tachometer line, and a pulse width modulation (PWM) line. Instead of controlling the air mover speed by varying the application of power, in a four-wire air mover, an air mover speed command is sent via a PWM line so that a microcontroller on the air mover adjusts the air mover speed with a constant voltage supply.

[0006] In many cases, it may be desirable to implement bidirectional communications with an air mover in addition to communicating PWM and tachometer signals. For example, it may be desirable to implement communications that allow information to be retrieved from an air mover in addition to tachometer signals, such as data stored in a field replaceable unit of the air mover, dynamic data associated with the air mover (e.g., odometer, operating hours, current draw), logs, or other diagnostic data. As another example, it may be desirable to implement the communication of information other than PWM signals to an air mover, such as special commands or programming (e.g., firmware updates for the air mover).

[0007] Although some solutions exist for integrating such advanced communication technologies into air movers, such solutions have disadvantages. For example, introducing communication functionality into an air mover may result in design complexity because additional communication lines may be required and the existing electrical architecture of the air mover and the cables coupling the air mover to the thermal control system may need to be modified. Summary of the invention

[0008] According to the teachings of the present disclosure, disadvantages and problems associated with conventional methods for communicating with air movers may be significantly reduced or eliminated.

[0009] According to an embodiment of the present disclosure, an information processing system may include: an air mover configured to drive an air flow; and a processing component communicatively coupled to the air mover for controlling the operation of the air mover via: a first line configured to communicate an analog air mover speed command from the processing component to the air mover for controlling the speed of the air mover; and a second line configured to communicate analog tachometer information from the air mover to the processing component. At least one of the air mover and the processing component may be configured to initiate a serial digital communication mode via the first line and the second line. The air mover and the processing component may be configured to communicate information to each other via the first line and the second line during the serial digital communication mode according to a digital communication protocol.

[0010] According to these and other embodiments of the present disclosure, a method may be included in an information handling system comprising: an air mover configured to drive an air flow; and a processing component communicatively coupled to the air mover for controlling operation of the air mover via: a first line configured to communicate an analog air mover speed command from the processing component to the air mover for controlling the speed of the air mover; and a second line configured to communicate analog tachometer information from the air mover to the processing component: initiating a serial digital communication mode via the first line and the second line by one of the air mover and the processing component; and in response to initiating the serial digital communication mode, communicating information to each other via the first line and the second line according to a digital communication protocol during the serial digital communication mode by the air mover and the processing component.

[0011] The technical advantages of the present disclosure will be apparent to those skilled in the art from the drawings, descriptions and claims included herein. The objects and advantages of the embodiments will be achieved and realized at least by the elements, features and combinations particularly pointed out in the claims.

[0012] It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are not restrictive of the claims set forth in the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] A more complete understanding of embodiments of the present invention and advantages thereof may be obtained by referring to the following description taken in conjunction with the accompanying drawings, in which like reference numerals indicate like features, and in which:

[0014] Figure 1A block diagram of an example information processing system according to an embodiment of the present disclosure is shown; and

[0015] FIG. 2A to FIG. 2C A flow chart of an example method for establishing a communication link between a management controller and a communication module according to an embodiment of the present disclosure is shown. DETAILED DESCRIPTION

[0016] By reference Figures 1 to 2C The preferred embodiments and their advantages are best understood wherein like reference numerals are used to designate like and corresponding parts.

[0017] For the purposes of this disclosure, an information handling system may include any tool or tool set operable to calculate, classify, process, transmit, receive, retrieve, generate, switch, store, display, indicate, detect, record, reproduce, dispose of or utilize any form of information, intelligence or data for commercial, scientific, control, entertainment or other purposes. For example, an information handling system may be a personal computer, a PDA, a consumer electronic device, a network storage device, or any other suitable device, and may vary in size, shape, performance, functionality, and price. An information handling system may include a memory, one or more processing resources, such as a central processing unit (CPU) or hardware or software control logic. Additional components of an information handling system may include one or more storage devices, one or more communication ports for communicating with external devices, and various input and output (I / O) devices (such as a keyboard, a mouse, and a video display). An information handling system may also include one or more buses operable to transmit communications between various hardware components.

[0018] For purposes of this disclosure, computer-readable media may include any tool or collection of tools that can retain data and / or instructions for a period of time. Computer-readable media may include, but are not limited to: storage media such as direct access storage devices (e.g., hard drives or floppy disks), sequential access storage devices (e.g., tape disk drives), optical disks, CD-ROMs, DVDs, random access memories (RAM), read-only memories (ROM), electrically erasable programmable read-only memories (EEPROM), and / or flash memories; and communication media such as wires, optical fibers, microwaves, radio waves, and other electromagnetic and / or optical carrier waves; and / or any combination of the foregoing.

[0019] For the purposes of this disclosure, information processing resources may broadly refer to any component system, device or equipment of an information processing system, including but not limited to processors, buses, memories, I / O devices and / or interfaces, storage resources, network interfaces, motherboards, integrated circuit packages; electromechanical devices (e.g., air movers), displays, and power supplies.

[0020] Figure 1 A block diagram of an example information handling system 102 according to an embodiment of the present disclosure is shown. In some embodiments, the information handling system 102 may include a server chassis configured to accommodate multiple servers or "blades". In other embodiments, the information handling system 102 may include a personal computer (e.g., a desktop computer, a laptop computer, a mobile computer, and / or a notebook computer). In other embodiments, the information handling system 102 may include a storage enclosure configured to accommodate multiple physical disk drives and / or other computer-readable media for storing data. Figure 1 As shown, information handling system 102 may include chassis 100 that houses processor 103, memory 104, temperature sensor 106, air mover 108, management controller 112, cable 124 for communicatively coupling air mover 108 to management controller 112, device 116, heat removal medium 122, and power line (+) 128 and ground line (-) 130 from which air mover 108 can draw power for operation.

[0021] The processor 103 may include any system, device or apparatus operable to interpret and / or execute program instructions and / or process data, and may include, but is not limited to, a microprocessor, a microcontroller, a digital signal processor (DSP), an application specific integrated circuit (ASIC), or any other digital or analog circuit configured to interpret and / or execute program instructions and / or process data. In some embodiments, the processor 103 may interpret and / or execute program instructions and / or process data stored in the memory 104 and / or another component of the information processing system 102.

[0022] Memory 104 may be communicatively coupled to processor 103 and may include any system, device, or apparatus operable to retain program instructions or data for a period of time. Memory 104 may include random access memory (RAM), electrically erasable programmable read-only memory (EEPROM), a PCMCIA card, flash memory, a magnetic storage device, an optical magnetic storage device, or any suitable option that retains data after power to information handling system 102 is removed, and / or a set of volatile or non-volatile memories.

[0023] Air mover 108 may include any mechanical or electromechanical system, device, or apparatus operable to move air and / or other gases in order to cool the information processing resources of information processing system 102. In some embodiments, air mover 108 may include a fan (e.g., a rotating arrangement of blades or vanes that act on air). In other embodiments, air mover 108 may include a blower (e.g., a centrifugal fan that uses a rotating impeller to accelerate air received at its air inlet and change the direction of the airflow). In these and other embodiments, the rotating components and other moving components of air mover 108 may be driven by motor 110. The rotational speed of motor 110 may be controlled by an air mover control signal communicated from thermal control system 114 of management controller 112. In operation, air mover 108 may cool the information processing resources of information processing system 102 by: drawing cool air from outside the chassis into an enclosure housing the information processing resources; exhausting warm air from inside the enclosure to outside the enclosure; and / or moving air across one or more heat sinks (not explicitly shown) inside the enclosure to cool the one or more information processing resources.

[0024] The management controller 112 may include any system, device or apparatus configured to facilitate the management and / or control of the information handling system 102 and / or one or more of its component information handling resources. The management controller 112 may be configured to issue commands and / or other signals for managing and / or controlling the information handling system 102 and / or its information handling resources. The management controller 112 may include a microprocessor, a microcontroller, a DSP, an ASIC, a field programmable gate array ("FPGA"), an EEPROM, or any combination thereof. The management controller 112 may also be configured to provide an out-of-band management facility for managing the information handling system 102. Such management may be performed by the management controller 112 even if the information handling system 102 is powered off or powered on to a standby state. In certain embodiments, the management controller 112 may include or may be an integral part of a baseboard management controller (BMC), a remote access controller (e.g., a Dell remote access controller or an integrated Dell remote access controller), or a shell controller. In other embodiments, the management controller 112 may include or may be an integral part of a chassis management controller (CMC).

[0025] like Figure 1As shown, management controller 112 may include thermal control system 114. Thermal control system 114 may include any system, device, or apparatus configured to receive one or more signals indicative of one or more temperatures within information handling system 102 (e.g., one or more signals from one or more temperature sensors 106), and based on such signals, calculate air mover drive signals to maintain appropriate cooling levels, increase cooling, or decrease cooling as appropriate, and communicate such air mover drive signals to air movers 108 (e.g., pulse width modulated signals on PWM line 134 of cable 124). In these and other embodiments, thermal control system 114 may be configured to receive information from other information handling resources and calculate air mover drive signals based on such received information in addition to temperature information. For example, as described in more detail below, thermal control system 114 may receive configuration data from device 116 and / or other information handling resources of information handling system 102, which configuration data may include thermal requirements of one or more information handling resources. In addition to temperature information collected from sensors within information handling system 102, thermal control system 114 may also calculate air mover drive signals based on such information received from information handling resources.

[0026] The temperature sensor 106 may be any system, device, or apparatus (e.g., a thermometer, a thermistor, etc.) configured to communicate a signal indicative of a temperature within the information handling system 102 to the management controller 112 or another controller. In many embodiments, the information handling system 102 may include multiple temperature sensors 106, where each temperature sensor 106 detects the temperature of a particular component and / or location within the information handling system 102.

[0027] Device 116 may include any component information handling system of information handling system 102, including but not limited to a processor, bus, memory, I / O devices and / or interfaces, storage resources, network interface, motherboard, integrated circuit packaging, electromechanical devices, display, and power supply.

[0028] like Figure 1 As shown, the device 116 may be mechanically and thermally coupled to the heat removal medium 122. The heat removal medium 122 may include a device configured to remove heat from the information processing resource (e.g., the device 116, such as Figure 1 The heat removal medium 122 may include any system, device, or apparatus that transfers heat (as shown) to reduce the temperature of the information processing resource. For example, the heat removal medium 122 may include a solid body (e.g., a heat pipe, a heat sink, a heat sink, a fin stack, etc.) that is thermally coupled to the information processing resource so that the heat generated by the information processing resource is transferred from the information processing resource to the air surrounding the information processing resource. For example, in Figure 1In the illustrated embodiment, heat removal medium 122 may be thermally coupled to device 116 and arranged such that heat generated by device 116 is transferred to air driven by air mover 108 .

[0029] As described above, cable 124 may communicatively couple air mover 108 to thermal control system 114 and management controller 112. Cable 124 may include a plurality of electrically conductive wires (which may be electrically insulated from one another) extending generally in parallel along the length of cable 124. Cable 124 may also include suitable terminals at each end of cable 124, such as a connector (not expressly shown) for coupling to management controller 112 and a connector (not expressly shown) for coupling to air mover 108.

[0030] like Figure 1 As shown, cable 124 may include a tach wire 132 and a PWM wire 134. Thus, in operation, power wire 128 and ground wire 130 may provide electrical energy to motor 110 to drive airflow from air mover 108. Thermal control system 114 may control the speed of air mover 108 via a drive signal (e.g., a serial pulse width modulated signal) communicated through PWM wire 134. The tachometer ( Figure 1 108) may generate a signal indicative of the speed of the air mover 108, which may be communicated to the thermal control system 114 via the tach line 132, thereby providing feedback to the thermal control system 114 so that the thermal control system 114 can determine an appropriate drive signal by taking into account the measured air mover speed received via the tach line 132.

[0031] In addition to processor 103, memory 104, temperature sensor 106, air mover 108, management controller 112, cable 124, device 116, and heat removal medium 122, information processing system 102 may also include one or more other information processing resources. Figure 1 Only one air mover 108 and one device 116 are depicted. In embodiments of the present disclosure, information handling system 102 may include any number of air movers 108 and devices 116. However, in some embodiments, methods similar or identical to those described herein for cooling device 116 may be used to provide cooling to processor 103, memory 104, management controller 112, and / or any other information handling resources of information handling system 102.

[0032] In operation, thermal control system 114 and air movers 108 may be configured to operate in a plurality of modes, as described in more detail below. For example, in “normal” operation, thermal control system 114 and air movers 108 may operate in a conventional mode, such as Figure 2A In conventional mode, thermal control system 114 and air mover 108 may operate in a conventional manner, wherein thermal control system 114 communicates an analog PWM signal to air mover 108 via PWM line 134 to set the speed of motor 110 according to the duty cycle of the PWM signal, and air mover 108 communicates an analog tachometer signal (e.g., a pulse frequency modulated signal in which the frequency of the tachometer signal pulses is indicative of the rotational speed of motor 110) to thermal control system 114 via tachometer line 132.

[0033] As another example, thermal control system 114 and air mover 108 may be configured to operate in a first hybrid mode initiated by thermal control system 114, such as Figure 2B As depicted, this enables data to be digitally communicated between thermal control system 114 and air mover 108 via PWM line 134 and tachometer line 132 while maintaining adequate control over the speed of motor 110. Figure 2B As shown, thermal control system 114 and air mover 108 may begin operating in a conventional mode, and thermal control system 114 may initiate a first hybrid mode by communicating an attention signal ATTN, which may be a PWM signal at a frequency significantly different than the frequency of the analog PWM signal used to communicate the speed of motor 110. For example, in some embodiments, attention signal ATTN may be at a frequency four times greater than the analog PWM signal communicated by thermal control system 114. After communicating attention signal ATTN, thermal control system 114 may digitally communicate one or more commands or other data to air mover 108 in a serial manner via PWM line 134.

[0034] As a specific example, the digital data communicated from the thermal control system 114 to the air movers 108 during the first hybrid mode may take the following form:

[0035] ATTN PWM CMD[ARG1 ARG2 ARG3…]CRC

[0036] in:

[0037] ATTN may be an attention signal ATTN, which may be a PWM signal at a frequency significantly different from the frequency of the analog PWM signal used to communicate the speed of the motor 110;

[0038] ●PWM can be a digital representation of the desired analog PWM signal (e.g., eight bits in length);

[0039] CMD may be a command to the air mover 108 (e.g., eight bits in length), examples of which include:

[0040] ○ No command (e.g., only set PWM);

[0041] o Read the status of the air mover 108;

[0042] o Read the health of the air mover 108;

[0043] ○ Setting the parameters of the air mover 108;

[0044] o Update the firmware of the air mover 108;

[0045] ARG1, ARG2, ARG3, etc. may include one or more arguments to the command represented by CMD, and such arguments may vary based on the command issued; and

[0046] ●CRC may be a cyclic redundancy check to detect data packet corruption in the communication of digital commands. In response to receiving the attention command ATTN, the air mover 108 may temporarily stop generating the analog tachometer signal, wait to receive commands or other data from the thermal control system 114 via the PWM line 134, and then digitally communicate one or more responses to the commands and / or data received from the thermal control system 114 in a serial manner via the tachometer line 132.

[0047] As a specific example, the digital data communicated from the air mover 108 to the thermal control system 114 during the first hybrid mode may take the following form:

[0048] RC ERRINT TACH[DATAn]CRC

[0049] in:

[0050] RC may include a return code (e.g., 00 for success, 01 for error);

[0051] • ERRINT may be an error interrupt which, if asserted, indicates that air mover 108 has detected a condition that should be checked by thermal control system 114;

[0052] TACH may be a digital representation of an analog tachometer signal (e.g., eight bits in length);

[0053] DATAn may include data responsive to commands CMD communicated from the thermal control system 114, and such commands may vary from command to command; and

[0054] ●CRC can be a cyclic redundancy check to detect data packet corruption (packet damage) in the communication of digital commands.

[0055] After air movers 108 finish transmitting their responses to thermal control system 114 , thermal control system 114 and air movers 108 may return to operating in the conventional mode.

[0056] As yet another example, thermal control system 114 and air mover 108 may be configured to operate in a second hybrid mode initiated by air mover 108, such as Figure 2C As depicted, this enables data to be digitally communicated between thermal control system 114 and air mover 108 via PWM line 134 and tachometer line 132 while maintaining adequate control over the speed of motor 110. Figure 2C As shown, thermal control system 114 and air mover 108 may begin operating in the conventional mode, and air mover 108 may initiate the second hybrid mode by communicating a fan interrupt signal FANINT via tachometer line 132, which may be a signal at a frequency significantly different than the frequency used to communicate the analog tachometer signal indicating the speed of motor 110. For example, in some embodiments, fan interrupt signal FANINT may be at a frequency two or more times greater than the frequency indicating the maximum speed of motor 110. After communicating fan interrupt signal FANINT, air mover 108 may suspend communicating the analog tachometer signal.

[0057] Receipt of fan interrupt signal FANINT may serve as a trigger to thermal control system 114 that thermal control system 114 should issue a command to determine the health and / or status of air movers 108. Thus, in response to receiving fan interrupt signal FANINT, thermal control system 114 may communicate an attention signal ATTN (described above) via PWM line 134 and a command (described above) via PWM line 134 to check the status and / or health of air movers 108. In response, air movers 108 may communicate a response (described above) via tachometer line 132 indicating the reason why air mover 108 generated the interrupt.

[0058] After air movers 108 finish transmitting their responses to thermal control system 114 , thermal control system 114 and air movers 108 may return to operating in the conventional mode.

[0059] Thus, the above described systems and methods may enable an extensible command set communicated via a serial digital protocol to digitally communicate commands on PWM lines 134 and digitally read commands from air movers 108 on tachometer lines 132. The serial digital protocol may be initiated by either thermal control system 114 or air movers 108.

[0060] The serial digital protocol may be a bidirectional protocol layered over an analog legacy protocol. Backward compatibility of the analog legacy protocol may be maintained because the legacy thermal control system 114 may simply ignore the fan interrupt signal FANINT and the legacy air mover 108 may simply ignore the attention signal ATTN. The command set may be extensible and optimized for specific applications and use cases.

[0061] The above-described systems and methods may also enable out-of-band host interrupts (e.g., fan interrupt signal FANINT) generated by air mover 108 to allow command / response sequences initiated by air mover 108 without requiring additional interfaces over the existing interfaces of tachometer line 132 and PWM line 134.

[0062] The above-described systems and methods may also enable dynamically querying and updating the air movers via commands from the thermal control system 114 to set modes, report status, update monitor behaviors (update watchdog behaviors), and / or update other functional behaviors. The above-described systems and methods may additionally enable retrieval of error logs, operational histories, and observed environmental conditions of the air movers without the need for additional interfaces. The above-described systems and methods may also enable updating of the firmware of the air movers 108 without the need for additional interfaces.

[0063] As used herein, when two or more elements are referred to as being “coupled” to each other, the term indicates that such two or more elements are in electronic or mechanical communication, where applicable, whether indirectly or directly connected, with or without intervening elements.

[0064] The present disclosure covers all changes, substitutions, changes, alterations and modifications to the example embodiments of this article that would be conceived by a person of ordinary skill in the art. Similarly, the appended claims cover all changes, substitutions, changes, alterations and modifications to the example embodiments of this article that would be conceived by a person of ordinary skill in the art, where appropriate. In addition, the references to the device or system or the parts of the device or system adapted to, arranged to, capable of, configured to, enabled to, operable to, or operated to perform a specific function in the appended claims cover the device, system or part, whether or not the device, system or part or the specific function is activated, turned on or unlocked, as long as the device, system or part is adapted to, arranged to, capable of, configured to, enabled to, operable to, or operated to perform the specific function. Therefore, without departing from the scope of the present disclosure, the system, device and method described herein may be modified, added or omitted. For example, the parts of the system and device may be integrated or separate. In addition, the operation of the system and device disclosed herein may be performed by more, less or other parts, and the described method may include more, less or other steps. In addition, the steps may be performed in any suitable order. As used in this document, "each" refers to each member of a set or each member of a subset of a set.

[0065] Although exemplary embodiments are shown in the drawings and described below, the principles of the present disclosure may be implemented using any number of techniques, whether currently known or not. The present disclosure should in no way be limited to the exemplary embodiments and techniques shown in the drawings and described above.

[0066] Unless specifically noted otherwise, the articles depicted in the drawings are not necessarily drawn to scale.

[0067] All examples and conditional language described herein are intended for teaching purposes to help readers understand the present disclosure and concepts that the inventor has contributed to advance the present technology, and are interpreted as not being limited to such specifically described examples and conditions. Although the embodiments of the present disclosure have been described in detail, it should be understood that various changes, substitutions and modifications may be made to the present disclosure without departing from the spirit and scope of the present disclosure.

[0068] Although specific advantages have been listed above, various embodiments may include some, none, or all of the listed advantages. In addition, other technical advantages may become apparent to those of ordinary skill in the art after reviewing the above drawings and descriptions.

Claims

1. An information processing system, comprising: an air mover configured to drive an air flow; as well as a processing component communicatively coupled to the air mover for controlling operation of the air mover via: a first line configured to communicate a simulated air mover speed command from the processing component to the air mover for controlling a speed of the air mover; as well as a second line configured to communicate analog tachometer information from the air mover to the processing component; and wherein at least one of the air mover and the processing component is configured to initiate a serial digital communication mode, wherein the processing component initiates the serial digital communication mode via the first line and information is communicated from the processing component to the air mover via the first line, and the air mover initiates the serial digital communication mode via the second line and information is communicated from the air mover to the processing component via the second line according to a digital communication protocol.

2. The information handling system of claim 1, wherein the analog air mover speed command comprises an analog pulse width modulated signal such that the speed of the air mover is set according to a duty cycle of the analog pulse width modulated signal.

3. The information handling system of claim 2, wherein the processing component is configured to initiate the serial digital communication mode by communicating a pulse width modulated signal via the first line at a frequency significantly different from a frequency of the analog pulse width modulated signal.

4. The information handling system of claim 1, wherein the analog tachometer information comprises a series of pulses indicating the speed of the air mover based on a frequency of the series of pulses.

5. The information handling system of claim 4, wherein the air mover is configured to initiate the serial digital communication mode by communicating a pulse signal via the second line at a frequency significantly different than the frequency of the series of pulses.

6. The information processing system of claim 1, wherein: The processing component is configured to initiate the serial digital communication mode by communicating an initiation signal via the first line; and In response to the processing component initiating the serial digital communication mode, the processing component communicates commands to the air mover via the first line in accordance with the digital communication protocol.

7. The information handling system of claim 6, wherein in response to receiving the command, the air mover communicates a response to the processing component via the second line in accordance with the digital communication protocol.

8. The information processing system of claim 1, wherein: The air mover is configured to initiate the serial digital communication mode by communicating an initiation signal via the second line; and In response to the air mover initiating the serial digital communication mode, the air mover communicates an interrupt to the processing component via the second line in accordance with the digital communication protocol.

9. The information handling system of claim 8, wherein in response to the interrupt, the processing component communicates a command to the air mover via the first line in accordance with the digital communication protocol to determine why the air mover issued the interrupt.

10. The information handling system of claim 9, wherein in response to receiving the command, the air mover communicates a response to the processing component via the second line in accordance with the digital communication protocol, the response including information regarding why the air mover issued the interrupt.

11. An information processing method, the method being included in an information processing system, the information processing system comprising: an air mover configured to drive an air flow; and a processing component communicatively coupled to the air mover for controlling operation of the air mover via: a first line configured to communicate simulated air mover speed commands from the processing component to the air mover for controlling the speed of the air mover; and a second line configured to communicate simulated tachometer information from the air mover to the processing component: The air mover initiates a serial digital communication mode via the second line or the processing component initiates a serial digital communication mode via the first line; as well as In response to initiating the serial digital communication mode, information is communicated by the air mover to the processing component via the second line and by the processing component to the air mover via the first line during the serial digital communication mode according to a digital communication protocol.

12. The method of claim 11, wherein the simulated air mover speed command comprises a simulated pulse width modulated signal such that the speed of the air mover is set according to a duty cycle of the simulated pulse width modulated signal.

13. The method of claim 12, further comprising the processing component initiating the serial digital communication mode by communicating a pulse width modulated signal via the first line at a frequency significantly different than a frequency of the analog pulse width modulated signal.

14. The method of claim 11, wherein the analog tachometer information comprises a series of pulses indicating the speed of the air mover based on a frequency of the series of pulses.

15. The method of claim 14 further comprising the air mover initiating the serial digital communication mode by communicating a pulse signal via the second line at a frequency significantly different than the frequency of the series of pulses.

16. The method of claim 11, further comprising: the processing component initiating the serial digital communication mode by communicating an initiation signal via the first line; as well as In response to the processing component initiating the serial digital communication mode, commands are communicated by the processing component to the air mover via the first line in accordance with the digital communication protocol.

17. The method of claim 16, further comprising, in response to receiving the command, communicating, by the air mover, a response to the processing component via the second line in accordance with the digital communication protocol.

18. The method of claim 11, further comprising: the air mover initiating the serial digital communication mode by communicating an initiation signal via the second line; as well as In response to the air mover initiating the serial digital communication mode, an interrupt is communicated by the air mover to the processing component via the second line according to the digital communication protocol.

19. The method of claim 18, further comprising, in response to the interrupt, communicating a command to the air mover via the first line in accordance with the digital communication protocol to determine why the air mover issued the interrupt.

20. The method of claim 19, further comprising, in response to receiving the command, communicating, by the air mover via the second line to the processing component, a response according to the digital communication protocol, the response including information regarding why the air mover issued the interrupt.

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