Abstract:
A method and system is disclosed for controlling cooling unit operational settings according to power dissipation levels in sub-equipment. The method and system includes an adaptive cooling controller which uses system configuration information to associate a particular cooling unit with particular sub-equipment, and further uses configuration information to associate cooling unit activity with respective sensors. At a given cooling unit setting, the adaptive cooling controller determines from sensor readings in the associated sub-equipment whether a cooling unit setting change is required according to the configuration information for the sub-equipment. The sensor readings may include both temperature and power dissipation readings. The method and system is particularly useful for overcoming the difficulty with accommodating sub-equipment changes of cooling unit controllers known in the art.

Description:
FIELD OF THE INVENTION 
       [0001]    The invention is directed to equipment cooling and in particular cooling directed to the specific equipment configuration equipped at point of use and in consideration of the power consumption thereof. 
       BACKGROUND OF THE INVENTION 
       [0002]    Cooling systems for electronic equipment are designed to be able to meet the maximum configurations for load, temperatures and other operating conditions to avoid system malfunctions or shutdowns at those operating points. A shelf assembly having a battery of cooling air intake fans will have fan speed and volumetric capacity sized to accommodate worse-case power dissipation and environmental temperature conditions over which the total equipment is specified to operate. 
         [0003]    In many cases having the cooling air intake fans run at a speed suitable for worse case conditions is undesirable. For example in partially controlled environments, for example for telecom equipment located in a central office, a significant portion of equipment operates below those worse-case temperature conditions the same equipment might experience in an exterior deployment. As well, the nature of the particular equipment furnished within the system may make have less demand for cooling than an alternate piece of equipment furnished at the same system location. 
         [0004]    Disadvantageously, provision of excess cooling capacity can result in significant wasted power, reduced reliability and shorter useful life of fans, and higher noise levels. 
       SUMMARY OF THE INVENTION 
       [0005]    It is an object of the invention to provide an improved form of adaptive cooling adapted to a power dissipation occurring on sub-equipment within a cooling equipment assembly. 
         [0006]    According to an aspect of the invention there is provided a method for adjusting the setting of a cooling unit, the method having the steps of: reading system configuration information; associating, based upon the system configuration information, at least one piece of sub-equipment with the cooling unit; associating, based upon the system configuration information, a sensor group with the cooling unit; obtaining sensor readings for the sensor group associated with the cooling unit; obtaining power dissipation readings for the at least one piece of sub-equipment; determining based upon the sensor readings, the system configuration information, and the power dissipation readings a value for a setting change to the cooling unit; and applying the setting change to the cooling unit. 
         [0007]    In some embodiments the cooling unit the cooling unit is a fan, the at least one piece of sub-equipment is a circuit card, and the setting is a fan speed setting. Also, the system configuration information has an association between the cooling unit and at least one sub-equipment location. In some of these embodiments, the cooling unit is a fan and the sub-equipment location is a circuit card slot in an equipment shelf. 
         [0008]    In some embodiments the system configuration information further has apparatus configuration information associated with the apparatus situated at the sub-equipment location. This apparatus configuration information may be an association between a cooling unit setting and a threshold value reading for the sensors associated with the apparatus wherein the association is further associated with a specific power dissipation. In some versions of the embodiments a guard band is associated with the threshold sensor value reading. 
         [0009]    According to one embodiment, if any of the sensor readings for the sensor group associated with the cooling unit exceed their respective threshold value plus the guard band value, then the setting change value is such as to increase the cooling effect of the cooling unit. Alternatively, if all of the sensor readings for the sensor group associated with the cooling unit are less than their respective threshold value minus the guard band value, then the setting change value is such as to decrease the cooling effect of the cooling unit. Further, if none of the sensor readings for the sensor group associated with the cooling unit exceed their respective threshold value plus the guard band value, and if at least one of the sensor readings for the sensor group associated with the cooling unit is within the guard band value range of their respective threshold value, then the setting change value is such as to not change the cooling effect of the cooling unit. 
         [0010]    According to another aspect of the invention there is disclosed a system for controlling the setting of a cooling unit, the system having: an adaptive cooling controller; a first system configuration information relating at least one piece of sub-equipment to the cooling unit; a second system configuration information associating a set of sensors to the cooling unit; a third system configuration information relating sensor readings to cooling unit settings at a power dissipation; whereby the adaptive cooling controller obtains sensor readings from the set of sensors specified by the second system configuration information; further obtains a power dissipation reading associated with the at least one piece of sub-equipment; and determines a setting change value to the cooling unit based upon the sensor readings, the power dissipation reading and the third system configuration information; and changes the setting of the cooling unit according to the setting change value. 
         [0011]    In some embodiments of this aspect, the cooling unit is a fan, the sensors are temperature sensors, the at least one piece of sub-equipment is a circuit card, and the setting corresponds to a speed. 
         [0012]    In some embodiments a portion of the set of sensors are located at the at least one piece of sub-equipment. Also a portion of the set of sensors are located so as to sense an ambient condition. 
         [0013]    In some embodiments the third system configuration information has an association between a cooling unit setting and a threshold value reading for the set of sensors at a power dissipation. Also, there are embodiments wherein the third system configuration information has an association between a cooling unit setting and a respective threshold value reading for a portion of sensors in the sub-set of sensors. 
         [0014]    In some embodiments a guard band is associated with the respective threshold value; and if any of the sensor readings for the portion of sensors have values which exceed the respective threshold value plus the guard band value for that sensor at the present cooling unit setting, then the adaptive cooling controller determines a value for a setting change which increases the cooling effect of the cooling unit. 
         [0015]    In some embodiments a guard band is associated with the respective threshold value; and if all of the sensor readings for the portion of sensors have values which are below the respective threshold value minus the guard band value for that sensor at the present cooling unit setting, then the adaptive cooling controller determines a value for a setting change which decreases the cooling effect of the cooling unit. 
         [0016]    In some embodiments a guard band is associated with the respective threshold value; and if none of the sensor readings for the portion of sensors have values which exceed the respective threshold value plus the guard band value for that sensor at the present cooling unit setting, and if at least one of the sensor readings of the portion of sensors is within the guard band value range of the respective threshold value, then the adaptive cooling controller determines a value for a setting change which does not alter the cooling effect of the cooling unit. 
         [0017]    In some of the contemplated embodiments, the cooling unit is a fan, the sensors are temperature sensors, and the setting change is associated with a change in fan speed. 
         [0018]    Note: in the following the description and drawings that follow merely illustrate the principles of the invention. It will thus be appreciated that those skilled in the art will be able to devise various arrangements that, although not explicitly described or shown herein, embody the principles of the invention and are included within its spirit and scope. Furthermore, all examples recited herein are principally intended expressly to be only for pedagogical purposes to aid the reader in understanding the principles of the invention and the concepts contributed by the inventors to furthering the art, and are to be construed as being without limitation to such specifically recited examples and conditions. Moreover, all statements herein reciting principles, aspects, and embodiments of the invention, as well as specific examples thereof, are intended to encompass equivalents thereof. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0019]    The foregoing and other objects, features and advantages of the invention will be apparent from the following more particular description of the preferred embodiments, as illustrated in the appended drawings, where: 
           [0020]      FIG. 1  illustrates a cooling enclosure for housing equipment having cooling needs according to a possible embodiment of the invention; 
           [0021]      FIG. 2  illustrates a block diagram of an adaptive cooling system according to an embodiment of the invention; 
           [0022]      FIG. 3  depicts a flow chart according to an embodiment of the invention; and 
           [0023]      FIG. 4  depicts a high-level block diagram of a computer subsystem suitable for use in performing functions described herein. 
       
    
    
       [0024]    In the following figures, like features bear similar reference labels. 
       DETAILED DESCRIPTION 
       [0025]    Referring to  FIG. 1  there may be seen a cooling system  100  according to an embodiment of the present invention. Enclosure  110  provides a mechanical frame in which electronic circuit cards or modules are disposed. In this embodiment the circuit cards are disposed in slots, similar to books along a shelf, and four such circuit cards  131 ,  132 ,  133 , and  134  are indicated. The remaining slots are filled with further circuit cards, some of which may be for the purposes of facilitating cooling air flow as will be described below. 
         [0026]    Shown in exploded view below enclosure  110  is fan assembly  120  which contains a plurality of fans mounted so as to draw in cooling air  102  and circulating such air into and through the circuit cards which are disposed in enclosure  110 . The design of enclosure  110  is such that after circulating past the circuit cards, the warmed cooling air is exhausted through ports (not shown in  FIG. 1 ), for example at the rear of the enclosure. Fan assembly  120  has been shown separated from the enclosure  110  for the purposes of this description, but in operation is located within or abutting the bottom of the enclosure, and secured so that cooling air drawn in by the plurality of fans is directed substantially upwards into the enclosure. Also visible mounted within fan assembly  120  are fan  122  and fan  124  as well as further fans. 
         [0027]    Under some scenarios, not all circuit cards mounted in enclosure  110  contain circuitry. In the example embodiment of  FIG. 1 , circuit cards  136 ,  137 ,  138  and  139  do not have electrical circuitry. Their presence in the system is for the purposes of preventing air flow from escaping from the enclosure by providing faceplates, and under some implementations, to provide a means of blocking airflow from passing through the location they occupy. This blockage facilitates the directing of the flow of cooling air to the cards which actually require cooling. 
         [0028]    The fans located in fan assembly  120  have their speed controlled by fan speed controllers (not shown) which allow the RPM of a fan to be set and monitored. 
         [0029]    The circuit cards disposed within enclosure  110  are equipped with at least one, and possibly a plurality of temperature sensors in the event that the particular circuit card requires cooling air flow to be adjusted. The temperature sensors generate a reading representative of a measured temperature in the vicinity of the sensor. 
         [0030]    Referring now to  FIG. 2 , there may be seen a block diagram  200  of an adaptive cooling system according to an embodiment of the invention. At the central position of the block diagram may be seen adaptive cooling control module (ACCM)  210 . This module is preferentially implemented as a series of functions described via software for execution upon a processor, although alternative implementations are discussed in reference to  FIG. 4  below. 
         [0031]    Accessible to ACCM  210  is system configuration information  220  and apparatus configuration information  230 . This information identifies several important considerations to ACCM  210 . System configuration information  220  identifies which fans&#39; air flow is associated with which apparatus mounting slot in enclosure  110 . For example, referring to  FIG. 1 , system configuration information  220  would identify that the enclosure slots containing circuit cards  131 ,  132 ,  133 , and  134  are associated with the air flow provided by fans  122  and  124 . Secondly, system configuration information  220  identifies the type of apparatus equipped in the enclosure slots. 
         [0032]    By way of example, according to one embodiment of the invention, system configuration information  220  may consist of information as contained in TABLE 1. 
         [0000]    
       
         
               
               
               
             
               
               
               
             
           
               
                 TABLE 1 
               
               
                   
               
               
                   
                   
                 Fan(s) # in 
               
               
                 Slot # 
                 Card Type 
                 direct air path 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                 1 
                 Gigabit Ethernet 
                 1(122); 2(124) 
               
               
                 2 
                 Ethernet 
                 1(122); 2(124) 
               
               
                 3 
                 Empty (Impedance) 
                 1(122); 2(124) 
               
               
                 4 
                 Empty (Impedance) 
                 1(122); 2(124) 
               
               
                 5 
                 Control 
                 3; 4 
               
               
                 6 
                 Control 
                 3; 4 
               
               
                 7 
                 ATM 
                 3; 4 
               
               
                 8 
                 ATM 
                 3; 4 
               
               
                 9 
                 Empty (Impedance) 
                 5; 6 
               
               
                 10 
                 Empty (Impedance) 
                 5; 6 
               
               
                 11 
                 Empty (Impedance) 
                 5; 6 
               
               
                 12 
                 Empty (Impedance) 
                 5; 6 
               
               
                 etc 
                 etc 
                 etc 
               
               
                   
               
             
          
         
       
     
         [0033]    Also accessible to ACCM  210  as part of system configuration information  220  is apparatus configuration information  230 . This information provides ACCM  210  with relations between temperatures as measured by the temperature sensors contained on the apparatus equipped in a slot of enclosure  110 , and fan speed requirements for the fans associated with that slot. 
         [0034]    By way of example, according to one embodiment of the invention, apparatus configuration information  230  may consist of information as contained in TABLE 2. In this table may be seen an association of Fan speed in RPM with maximum temperature readings for a first and second temperature sensor located on each card, and for an air inlet temperature sensor. 
         [0000]    
       
         
               
             
               
               
             
               
               
               
               
               
               
               
               
             
               
             
               
               
             
               
               
               
               
               
               
               
               
             
               
             
               
               
             
               
               
               
               
               
               
               
               
             
               
             
               
               
             
               
               
               
               
               
               
               
               
             
           
               
                 TABLE 2 
               
               
                   
               
             
             
               
                 Gigabit Ethernet Card 
               
             
          
           
               
                   
                 Fan speed, RPM 
               
             
          
           
               
                   
                 0 
                 1k 
                 2k 
                 3k 
                 4.5k 
                 5.5k 
                 6.5k 
               
               
                   
               
               
                 Maximum Card Sensor 1 
                 65 
                 40 
                 45 
                 65 
                 75 
                 85 
                 90 
               
               
                 Readings, ° C. 
               
               
                 Maximum Card Sensor 2 
                 65 
                 40 
                 45 
                 65 
                 80 
                 90 
                 95 
               
               
                 Readings, ° C. 
               
               
                 Air Inlet Ambient 
                 −20 
                 −10 
                 0 
                 25 
                 40 
                 55 
                 65 
               
               
                 Temperatures, ° C. 
               
               
                   
               
             
          
           
               
                 ATM Card 
               
             
          
           
               
                   
                 Fan speed, RPM 
               
             
          
           
               
                   
                 0 
                 1k 
                 2k 
                 3k 
                 4k 
                 5k 
                 6k 
               
               
                   
               
               
                 Maximum Card Sensor 1 
                 55 
                 30 
                 35 
                 55 
                 65 
                 75 
                 80 
               
               
                 Readings, ° C. 
               
               
                 Maximum Card Sensor 2 
                 50 
                 25 
                 30 
                 50 
                 60 
                 70 
                 75 
               
               
                 Readings, ° C. 
               
               
                 Air Inlet Ambient 
                 −20 
                 −10 
                 0 
                 25 
                 40 
                 55 
                 65 
               
               
                 Temperatures, ° C. 
               
               
                   
               
             
          
           
               
                 ETHERNET Card 
               
             
          
           
               
                   
                 Fan speed, RPM 
               
             
          
           
               
                   
                 0 
                 2k 
                 3k 
                 4k 
                 5k 
                 6k 
                 7k 
               
               
                   
               
               
                 Maximum Card Sensor 1 
                 60 
                 35 
                 40 
                 60 
                 70 
                 80 
                 85 
               
               
                 Readings, ° C. 
               
               
                 Maximum Card Sensor 2 
                 70 
                 40 
                 45 
                 65 
                 75 
                 85 
                 90 
               
               
                 Readings, ° C. 
               
               
                 Air Inlet Ambient 
                 −20 
                 −10 
                 0 
                 25 
                 40 
                 55 
                 65 
               
               
                 Temperatures, ° C. 
               
               
                   
               
             
          
           
               
                 CONTROL Card 
               
             
          
           
               
                   
                 Fan speed, RPM 
               
             
          
           
               
                   
                 0 
                 2k 
                 3k 
                 4k 
                 5k 
                 6k 
                 7k 
               
               
                   
               
               
                 Maximum Card Sensor 1 
                 65 
                 40 
                 45 
                 65 
                 75 
                 85 
                 90 
               
               
                 Readings, ° C. 
               
               
                 Maximum Card Sensor 2 
                 80 
                 50 
                 55 
                 75 
                 85 
                 95 
                 100 
               
               
                 Readings, ° C. 
               
               
                 Air Inlet Ambient 
                 −30 
                 −10 
                 0 
                 25 
                 40 
                 55 
                 65 
               
               
                 Temperatures, ° C. 
               
               
                   
               
             
          
         
       
     
         [0035]    The highest RPM required over the operating temperature range is defined per card based on thermal testing results performed during card&#39;s design and verification, and can be updated in the field if via updating apparatus configuration information  230  if the card&#39;s thermal profile has changed for some reason (for example, a newer SW load, new substitution part, etc. . . . ). 
         [0036]    The temperatures listed in TABLE 2 represent the threshold temperature for the highest allowable temperature at the given fan RPM. In general, if at a given fan RPM the temperature observed on a sensor is in excess of the value indicated in the table, then the fan speed is increased. Likewise, if the temperature observed on a sensor is below the value indicated in the table, the fan speed may be decreased. 
         [0037]    In order to prevent speed oscillations or hunting for appropriate fan speeds, a guard band of temperatures is established around the indicated temperature. This guard band is normally specified in the system configuration information  220 , but may also be stored in the ACCM  210 . This guard band may be a range of temperatures ±2° around the indicated temperature, or ±4°, or ±6°, or another appropriate range as determined by either enclosure design or via equipment characterization. Should the measured temperature fall within the specified guard band for that sensor, then no change in fan RPM is required. 
         [0038]    Referring back to  FIG. 2 , the ACCM  210  is also connected to fan controller  250  to which it provides fan speed requirements. Fan controller  250  then provides appropriate drive voltages to the individual fans located in fan assembly  120  so as to set them to the speed as specified by ACCM  210 . 
         [0039]    According to one embodiment of the invention, operation of the ACCM  210  in order to provide appropriate cooling air flow to the furnished apparatus is as follows. 
         [0040]    Using the information provided in the system configuration information  220 , the ACCM  210  can associate a group of temperature sensors located upon equipment installed in the enclosure slots to a particular fan. The group of sensors associated with a particular fan may be referred to as the Fan Sensor Group (FSG). By way of example, referring to TABLE 1, the FSG for fan  1  (fan  122  of  FIG. 1 ) are the temperature sensors associated with the first four enclosure slots (any temperature sensors on apparatus cards  131 ,  132 ,  133 , and  134  of  FIG. 1 ) and in the case that inlet air ambient temperature sensors are provided, also those sensors. 
         [0041]    For each fan, the ACCM  210  collects sensor readings for the fan&#39;s respective FSG. As the RPM of the fan is known, as the ACCM  210  has set it, then the ACCM  210  may use the data provided by the apparatus configuration information  230  to determine if any of the temperature sensors of a particular FSG exceed their highest allowable (plus guard band) temperatures. If any sensor in the FSG exceeds, then the speed of the respective fan is increased. If none of the temperature readings of the FSG are above the threshold temperature (plus guard band), then the present fan speed is not too low. ACCM  210  then determines if any of the temperature readings are within their respective guard band for that fan speed. If none of the temperature readings are within their respective guard bands, then all temperatures must be below threshold and the present fan speed may be decreased, and the ACCM  210  instructs fan controller  250  to do so for this fan. However, if at this point, at least one sensor reading within the FSG is within its respective guard band, then the fan speed need neither be increased nor decreased. 
         [0042]    By referring to TABLE 2 it may be seen that the fan speeds given for a particular card are not specified for other apparatus. For example, the Gigabit Ethernet Card entry in the table specifies sensor temperatures for a fan speed of 5.5 k RPM, while the other cards of TABLE 2 only specify sensor temperatures for fan speeds of 5 k RPM and 6 k RPM. Under circumstances where a fan speed is set and no specific temperature is given for the apparatus which is part of the FSG, the ACCM  210  will calculate an appropriate temperature for the sensor at issue. This calculation may be performed by using routine linear interpolation or extrapolation from the threshold temperatures provided. 
         [0043]    The temperature thresholds and fan speed for which the apparatus configuration information in TABLE 2 was derived represents a particular instance of power consumption for the card under consideration. According to an embodiment of the invention, the temperature thresholds and associated fan speeds can be usefully altered according to a consideration of the power dissipation occurring on the card under consideration. Power monitoring, which consists of a reading of the present power dissipation of the card, allows for a characterization of a card which may better account for wide load swing dissipating components than just temperature sensors. A card&#39;s power dissipation may vary depending upon instantaneous load conditions, which in themselves may vary depending upon time of day and other network variables, and the card&#39;s specific configuration or status, such as off-line or standby. 
         [0044]    In order to account for the power dissipation occurring on the card, the apparatus configuration information  230  may be supplemented by further instances of relations between temperatures as measured by the temperature sensors contained on the apparatus equipped in a slot of enclosure  110 , and fan speed requirements for the fans associated with that slot, wherein the further instances are representative of relations for different instances of power dissipation. 
         [0045]    By way of example, according to one embodiment of the invention, apparatus configuration information  230  may further consist of information as contained in TABLE 3. 
         [0046]    In this table may be seen an association of card type to power dissipation levels. Each of the different cards has a power threshold level which indicates the boundary of a zone. For example, for the Gigabit Ethernet Card, a reading from the power monitoring circuitry which indicated 38 Watts of dissipation on the card at the time of the reading would indicate that the card was operating in the low-power zone, whereas a reading at the 48 Watt level would indicate that the card was operating in the mid-power zone. 
         [0000]    
       
         
               
               
             
               
               
               
               
               
             
           
               
                   
                 TABLE 3 
               
             
             
               
                   
                   
               
               
                   
                 Power - Watts 
               
             
          
           
               
                   
                 CARD TYPE 
                 low 
                 mid 
                 high 
               
               
                   
                   
               
               
                   
                 Gigabit Ethernet Card 
                 40 
                 50 
                 60 
               
               
                   
                 ATM Card 
                 20 
                 25 
                 30 
               
               
                   
                 ETHERNET Card 
                 35 
                 45 
                 55 
               
               
                   
                 CONTROL Card 
                 45 
                 60 
                 75 
               
               
                   
                   
               
             
          
         
       
     
         [0047]    Each zone is associated with a different instance of relations between temperatures as measured by the temperature sensors, and fan speed requirements for the fans associated with that slot. 
         [0048]    By way of example, according to one embodiment of the invention, apparatus configuration information  230  may further consist of information as contained in TABLE 4. This table shows a portion of the apparatus configuration information  230  as is relevant to the Gigabit Ethernet Card example. 
         [0000]    
       
         
               
             
               
               
             
               
               
               
               
               
               
               
               
             
               
             
               
               
             
               
               
               
               
               
               
               
               
             
               
             
               
               
             
               
               
               
               
               
               
               
               
             
           
               
                 TABLE 4 
               
               
                   
               
             
             
               
                 Gigabit Ethernet Card - Low Power &lt;40 Watts 
               
             
          
           
               
                   
                 Fan speed range, RPM 
               
             
          
           
               
                   
                 0 
                 0 
                 1K 
                 2K 
                 3K 
                 4.5K 
                 5.5K 
               
               
                   
               
               
                 Max Card Sensor 1 
                 65 
                 40 
                 45 
                 65 
                 75 
                 85 
                 90 
               
               
                 Readings, ° C. 
               
               
                 Max Card Sensor 2 
                 65 
                 40 
                 45 
                 65 
                 80 
                 90 
                 95 
               
               
                 Readings, ° C. 
               
               
                 Air Inlet Ambient 
                 −20 
                 −10 
                 0 
                 25 
                 40 
                 55 
                 65 
               
               
                 Temperatures, ° C. 
               
               
                   
               
             
          
           
               
                 Gigabit Ethernet Card - Medium Power 40 Watts to 50 Watts 
               
             
          
           
               
                   
                 Fan speed range, RPM 
               
             
          
           
               
                   
                 0 
                 1K 
                 2K 
                 3K 
                 4.5K 
                 5.5K 
                 6.5K 
               
               
                   
               
               
                 Max Card Sensor 1 
                 65 
                 40 
                 45 
                 65 
                 75 
                 85 
                 90 
               
               
                 Readings, ° C. 
               
               
                 Max Card Sensor 2 
                 65 
                 40 
                 45 
                 65 
                 80 
                 90 
                 95 
               
               
                 Readings, ° C. 
               
               
                 Air Inlet Ambient 
                 −20 
                 −10 
                 0 
                 25 
                 40 
                 55 
                 65 
               
               
                 Temperatures, ° C. 
               
               
                   
               
             
          
           
               
                 Gigabit Ethernet Card - High Power &gt;50 Watts 
               
             
          
           
               
                   
                 Fan speed range, RPM 
               
             
          
           
               
                   
                 1K 
                 2K 
                 3K 
                 4.5K 
                 5.5K 
                 6.5K 
                 6.5K 
               
               
                   
               
               
                 Max Card Sensor 1 
                 65 
                 40 
                 45 
                 65 
                 75 
                 85 
                 90 
               
               
                 Readings, ° C. 
               
               
                 Max Card Sensor 2 
                 65 
                 40 
                 45 
                 65 
                 80 
                 90 
                 95 
               
               
                 Readings, ° C. 
               
               
                 Air Inlet Ambient 
                 −20 
                 −10 
                 0 
                 25 
                 40 
                 55 
                 65 
               
               
                 Temperatures, ° C. 
               
               
                   
               
             
          
         
       
     
         [0049]    In this table may be seen an association of Fan speed in RPM with maximum temperature readings for a first and second temperature sensor located on each card, and for an air inlet temperature sensor for a particular target life. For the purposes of this example, multiple instances for one particular card, the Gigabit Ethernet Card, are shown. In actual embodiments, there will typically be multiple instances for each of the cards or sub-equipment provided. There may also be seen that for each of the power ranges there is a different set of associations. In operation, the actual power reading of the card will be used to select the appropriate set. 
         [0050]    Referring now to  FIG. 3 , there may be seen a flow diagram depicting the method just described. Commencing at step  310 , the ACCM obtains system configuration information, including apparatus configuration information. At step  312  it uses this information to identify fan sensor groups (FSGs) for each fan requiring controlling. At step  314  an initial fan RPM is set on each fan. This initial fan RPM may be a nominal value, for example, 50% of the fan&#39;s maximum RPM; or it may be 0 RPM in the case that the equipment is known to be located in a low temperature environs and it is not desirable to start the fans at very low temperatures; or alternatively the initial fan RPM may be derived from the fan settings appropriate to the FSG, for example the second highest RPM provided for the apparatus associated with the FSG. 
         [0051]    Moving now to step  316 , for each fan the ACCM obtains sensor readings from the sensors within each FSG. These temperature readings are obtained after a sufficient time delay for the sensors to reflect the effects of the set fan RPM. As well, for each unit of sub-equipment, for example a card, it obtains power dissipation readings. 
         [0052]    At step  320  the ACCM ascertains if any of the sensor readings within the FSG under consideration are higher than the associated temperature threshold plus guard band for that sensor using temperature thresholds appropriate to the power dissipation. If any of the sensor readings are in excess of the associated temperature threshold plus guard band, then the process goes to step  322  where the ACCM increments the fan speed. Control then passes back to step  316  to ascertain the effects of the fan speed change. 
         [0053]    Alternatively, if at step  320  none of the sensor readings within the FSG under consideration are higher than the associated temperature threshold plus guard band for that sensor, then control passes to step  330 . 
         [0054]    At step  330  the ACCM determines if any of the sensor readings within the FSG under consideration are within the guard band around the associated temperature threshold for that sensor. If none of the sensor readings within the FSG under consideration are within the guard band around the associated temperature threshold for that sensor appropriate to the power dissipation, then the process goes to step  332  where the ACCM decrements the fan speed. Control then passes back to step  316  to ascertain the effects of the fan speed change. 
         [0055]    Alternatively, if at step  330  at least of the sensor readings within the FSG under consideration are within the guard band around the associated temperature threshold for that sensor appropriate to the power dissipation, then the speed of that particular fan need not be incremented nor decremented at this point in time. Control then passes back to step  316  to monitor the ongoing performance. 
         [0056]    In the embodiment described above, the apparatus was equipped each with a pair of temperature sensors. This was for illustrative purposes only, as alternative embodiments may employ only a single sensor. In general, however, a plurality of sensors is preferred for reliability purposes so that no single sensor failure precludes the ACCM from operating. 
         [0057]    Referring to  FIG. 4 , there may be seen a high-level block diagram of a computer subsystem suitable for use in performing functions described herein. 
         [0058]    As depicted in  FIG. 4 , computer subsystem  400  includes a processor element  402  (e.g., a central processing unit (CPU) and/or other suitable processor(s)), a memory  404  (e.g., random access memory (RAM), read only memory (ROM), and the Like), a cooperating module/process  405 , and various input/output devices  406  (e.g., storage devices (e.g., a tape drive, a floppy drive, a hard disk drive, a compact disk drive, a non-volatile memory device, and the like; or alternatively a connection to another processor)). 
         [0059]    It will be appreciated that the functions depicted and described herein may be implemented in software and/or hardware, e.g., using a general purpose computer, one or more application specific integrated circuits (ASIC), and/or any other hardware equivalents. In one embodiment, the cooperating process  405  can be loaded into memory  404  and executed by processor  402  to implement the functions as discussed herein. Thus, cooperating process  405  (including associated data structures) can be stored on a computer readable storage medium, e.g., RAM memory, magnetic or optical drive or diskette, non-volatile memory devices, and the like. 
         [0060]    It is contemplated that some of the steps discussed herein as software methods may be implemented within hardware, for example, as circuitry that cooperates with the processor to perform various method steps. Portions of the functions/elements described herein may be implemented as a computer program product wherein computer instructions, when processed by a computer, adapt the operation of the computer such that the methods and/or techniques described herein are invoked or otherwise provided. Instructions for invoking the inventive methods may be stored in non-transitory and tangible fixed or removable media, and/or stored within a memory within a computing device operating according to the instructions. 
         [0061]    In summary, a method and has been disclosed which provides a means to use system configuration information to adapt cooling unit settings, for example fan speed settings, to the requirements of the specific equipment furnished. The method and system uses system configuration information to associate cooling units to sub-equipment locations, to associate sensors at those and other locations with the cooling units, and to determine which variations in settings are appropriate at a given instant of operation based upon system configuration information relating cooling unit settings to sensor readings of sub-equipment power dissipation and temperature. 
         [0062]    It is to be understood that various changes in the details, materials, and arrangements of the parts which have been described and illustrated in order to explain the nature of this invention may be made by those skilled in the art without departing from the scope of the invention as expressed in the following claims. 
         [0063]    It should also be understood that the steps of the exemplary methods set forth herein are not necessarily required to be performed in the order described, and the order of the steps of such methods should be understood to be merely exemplary. Likewise, additional steps may be included in such methods, and certain steps may be omitted or combined, in methods consistent with various embodiments of the present invention. 
         [0064]    Although the elements in the following method claims, if any, are recited in a particular sequence with corresponding labeling, unless the claim recitations otherwise imply a particular sequence for implementing some or all of those elements, those elements are not necessarily intended to be limited to being implemented in that particular sequence. 
         [0065]    Reference herein to “one embodiment” or “an embodiment” means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the invention. The appearances of the phrase “in one embodiment” in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments necessarily mutually exclusive of other embodiments. The same applies to the term “implementation.” Numerous modifications, variations and adaptations may be made to the embodiment of the invention described above without departing from the scope of the invention, which is defined in the claims.