Sensors, multiplexed communication techniques, and related systems
An observed operational state can include an operational state of one or more system devices. A sensor can emit, in response to a detected observable condition reflective of a given operational state, a simulated signal reflective of a different operational state as a proxy for the detected condition. A controller receiving such a proxy signal can, at least partially responsively to the proxy signal, issue a command corresponding to the given operational state. For example, a leak detector can emit in response to a detected leak, or a flow-rate sensor can emit in response to a detected flow-rate of a liquid, a simulated fan-speed tachometer signal representative of a selected fan speed. At least partially in response to observing a simulated tachometer signal, a controller can issue a system command corresponding to an underlying system condition for which the simulated tachometer signal is a proxy.
1. A control system, comprising:
a sensor, coupled to a fan header, configured to observe an operational parameter, and responsive thereto, to simulate an output signal of a tachometer, the simulated output signal being indicative of a rotational speed parameter, wherein the sensor is further configured to emit, over a communication channel, the simulated output signal as a proxy for the observed operational parameter, wherein the observed operational parameter is different from the rotational speed parameter; and
a controller to receive the simulated signal over the communication channel and to interpret the simulated signal as corresponding to a state of the observed operational parameter.
2. A control system according to claim 1 , wherein the controller is further configured to emit a command signal responsive to the state of the observed operational parameter.
3. A control system according to claim 1 , wherein the simulated signal of the tachometer comprises a simulated fan-tachometer signal or a simulated pump speed signal.
4. A control system according to claim 3 , wherein the sensor comprises a leak detector, and wherein the observed operational parameter comprises a detected presence or a detected absence of a leak by the leak detector.
5. A control system according to claim 4 , wherein the leak detector comprises a sensitive region, wherein the sensitive region is operatively coupled to a printed circuit board adjacent a component susceptible to wetting by a working fluid if a leak of the working fluid occurs.
6. A control system according to claim 4 , wherein the observed operational parameter further comprises a location of a detected presence of a leak, and wherein the sensor is configured to simulate a first output signal of a tachometer corresponding to a first location, and a second output signal of a tachometer corresponding to a second location, wherein the first output signal has a different frequency than the second output signal.
7. A control system according to claim 3 , wherein the sensor comprises a flow-rate sensor, and wherein the observed operational parameter comprises an indicia of a rate-of-flow of a fluid.
8. A control system according to claim 1 , wherein the observed operational parameter consists of one or more of an indicia of temperature, an indicia of pressure, an indicia of electrical conductance, and an indicia of a presence or absence of a leak.
9. A control system according to claim 1 , wherein the observed operational parameter comprises an indicia of a presence or absence of a working fluid externally of a liquid-based heat-transfer system, wherein the sensor comprises an electrical circuit configured to emit the simulated signal responsive to the indicia of a presence of the working fluid externally of the liquid-based heat transfer system.
10. A control system according to claim 9 , wherein the electrical circuit is further configured to emit the simulated signal responsive to the indicia indicating an absence of the working fluid externally of the liquid-based heat transfer system.
11. A control system according to claim 10 , wherein the signal responsive to the indicia indicating a presence of the working fluid externally of the liquid-based heat transfer system comprises an interruption to the simulated signal.
12. A control system according to claim 9 , wherein the simulated signal comprises an interruption to at least one electrical coupling between a pump and the fan header.
13. A control system according to claim 12 , wherein the at least one electrical coupling between the fan pump and the fan header comprises a first electrical coupling between a first pump and a first fan header and a second electrical coupling between a second pump and a second fan header.
14. A control system according to claim 12 , wherein the electrical coupling comprises an electrical current for powering the pump, a PWM signal for controlling the pump, or an FG signal for monitoring operation of the pump.
15. A control system according to claim 1 , wherein the observed operational parameter comprises an indicia of a flow rate of a working fluid in a liquid-based heat-transfer system, wherein the sensor comprises an electrical circuit configured to emit the simulated signal in correspondence with the indicia of the flow rate.
16. A control system according to claim 1 , wherein the controller is configured to interrupt at least one electrical coupling between a pump and the fan header responsive to a predefined state of the observed operational parameter.
17. A control system according to claim 16 , wherein, responsive to the predefined state of the observed operational parameter, the controller is configured to alter a supply of power to the pump, wherein the simulated signal comprises a frequency generator (FG) signal output by the pump.
18. A control system according to claim 16 , wherein, responsive to the predefined state of the observed operational parameter, the interruption of the at least one electrical coupling between the pump and the fan header comprises an interruption to a pulse width modulated (PWM) signal to the pump with an alternative PWM signal to the pump configured to change a pump speed, wherein the simulated signal comprises a frequency generator (FG) signal output by the pump responsive to the alternative PWM signal.
19. A control system according to claim 16 , wherein, responsive to the predefined state of the observed operational parameter, the interruption of the at least one electrical coupling between the pump and the fan header comprises an interruption to a frequency generator (FG) signal output by the pump with the simulated signal comprising an alternative FG signal to an FG pin of the fan header.
20. A control system according to claim 1 , wherein the simulated signal comprises a simulated reproduction of a waveform emitted by a properly or an improperly operating, or a failed, fan or pump.
21. A control system according to claim 1 , wherein the communication channel comprises an intelligent platform management initiative (IPMI) communication bus.
22. A control system according to claim 1 , wherein the observed operational parameter further comprises an operational state of a pump, and wherein the sensor is configured to simulate a first output signal of a tachometer corresponding to a failed state of the pump, and a second output signal of a tachometer corresponding to an operating state of the pump, wherein the first output signal has a different frequency than the second output signal.
23. A control system according to claim 22 , wherein the observed operational parameter further comprises an identification of one of a plurality of pumps, and wherein the first output signal corresponds to a failed state of a first pump, the second output signal of a tachometer corresponds to an operating state of the first pump, wherein the sensor is configured to simulate a third output signal of a tachometer corresponding to a failed state of a second pump, and a fourth output signal of a tachometer corresponding to an operating state of the second pump, wherein the first, second, third, and fourth output signals each has a different respective frequency than the other output signals.
24. A control system according to claim 1 , wherein the sensor comprises a temperature sensor and the observed operational parameter further comprises an observed temperature, and wherein the sensor is configured to simulate a first output signal of a tachometer corresponding to a first temperature, and a second output signal of a tachometer corresponding to a second temperature, wherein the first output signal has a different frequency than the second output signal.
25. A method of detecting a leak of a working fluid from a liquid-based heat-transfer system, the method comprising:
sensing a presence or an absence of a working fluid externally of a liquid-based heat-transfer system with a sensor coupled to a fan header;
simulating an output signal of a tachometer, the simulated output signal simulating a tachometer signal indicative of a selected rotational speed in correspondence with the sensed absence or the sensed presence of the working fluid;
monitoring the simulated output signal; and
interpreting a presence or an absence of the working fluid externally of the liquid-based heat-transfer system from the selected rotation speed of the simulated output signal.
26. A method according to claim 25 , further comprising emitting a signal responsive to the monitored simulated output signal corresponding to a sensed presence of the working fluid.
27. A method according to claim 26 , wherein the emitted signal comprises an alert to a system administrator.
28. A method according to claim 26 , wherein the emitted signal comprises a command to a control system.
29. A method according to claim 25 , wherein the selected rotation speed corresponds to an actual rotational speed of a fan or pump.
30. A method according to 25 , wherein the simulated output signal in the sensed absence of the working fluid comprises a simulated tachometer signal of the type emitted by an operable fan or pump.
31. A method according to claim 25 , wherein the simulated output signal in the sensed presence of the working fluid comprises a simulated tachometer signal of the type emitted by an inoperable fan or pump.
32. A computer system, comprising:
a fluid conduit configured to convey a liquid there-through;
a sensor configured to detect a presence of the liquid externally of the conduit;
an electrical circuit operatively coupled to the sensor and being configured to emit a signal responsive to a detected presence of the liquid externally of the conduit, wherein the electrical circuit is further configured to simulate an output signal of a tachometer, the simulated output signal being indicative of a rotational speed parameter, and to emit the simulated output signal indicative of a selected rotation speed absent a detected presence of the liquid externally of the conduit;
a control circuit to interpret, from the selected rotation speed, a presence or an absence of the liquid externally of the conduit; and
a fan header and a pump electrically coupled to the header, wherein the electrical circuit is configured to interrupt at least one electrical coupling between the pump and the header in response to a detected presence of the liquid externally of the conduit.
33. A computer system according to claim 32 , wherein the signal responsive to a presence of the liquid externally of the conduit comprises an interruption to the simulated output signal.
34. A computer system according to claim 32 , wherein the signal responsive to the detected presence of the liquid externally of the conduit comprises an interruption to the at least one electrical coupling between the pump and the fan header.
35. A computer system according to claim 32 , further comprising a printed circuit board, wherein the sensor comprises a sensitive region operatively coupled to the printed circuit board at a position adjacent a component susceptible to wetting by the liquid if a leak of the liquid from the conduit occurs.
36. A computer system according to claim 32 , wherein the electrical circuit comprises:
a leak detection circuit configured to receive a signal from the sensor indicative of a leak, and to emit a signal on a leak sense line responsive to the signal received from the sensor;
a glue logic module configured to monitor the leak sense line for a signal indicative of a leak and to output at least one of: a signal to interrupt power to the pump and an interruption to a frequency generator (FG) signal output by the header with the simulated signal comprising an alternative FG signal; and
an enable detect line configured to carry a signal transmitted from the glue logic module to the leak detection circuit, wherein the leak detection circuit becomes operative responsive to receiving the signal on the enable detect line.
37. A control system, comprising:
a sensor configured to observe an operational parameter, and responsive thereto, to simulate an output signal of a tachometer, the simulated output signal being indicative of a rotational speed parameter, wherein the sensor is further configured to emit, over a communication channel, the simulated output signal as a proxy for the observed operational parameter, wherein the observed operational parameter is different from the rotational speed parameter; and
a controller to receive the simulated signal over the communication channel, to interpret the simulated signal as corresponding to a state of the observed operational parameter, and to interrupt at least one electrical coupling between a pump and a fan header responsive to a predefined state of the observed operational parameter.
38. A control system according to claim 37 , wherein the sensor comprises an electrical circuit configured to observe the operational parameter comprising an indicia of a presence or absence of a working fluid externally of a liquid-based heat-transfer system, and configured to simulate the output signal of a tachometer responsive to the indicia of a presence of the working fluid externally of the liquid-based heat transfer system.
39. A control system according to claim 38 , wherein the observed operational parameter comprises an indicia of a flow rate of a working fluid in a liquid-based heat-transfer system, wherein the sensor is configured to emit the simulated signal in correspondence with the indicia of the flow rate.
40. A control system according to claim 38 , wherein the electrical circuit is further configured to emit the simulated signal responsive to the indicia indicating an absence of the working fluid externally of the liquid-based heat transfer system.
41. A control system according to claim 38 , wherein the signal responsive to the indicia indicating a presence of the working fluid externally of the liquid-based heat transfer system comprises an interruption to the simulated signal.
42. A control system according to claim 37 , wherein the controller is further configured to emit a command signal responsive to the state of the observed operational parameter.
43. A control system according to claim 42 , wherein the simulated signal of the tachometer comprises a simulated fan-tachometer signal or a simulated pump speed signal.
44. A control system according to claim 37 , wherein the sensor comprises a flow-rate sensor, and wherein the observed operational parameter comprises an indicia of a rate-of-flow of a fluid.
45. A control system according to claim 37 , wherein the observed operational parameter consists of one or more of an indicia of temperature, an indicia of pressure, an indicia of electrical conductance, and an indicia of a presence or absence of a leak.
46. A control system according to claim 37 , wherein the sensor comprises a leak detector, and wherein the observed operational parameter comprises a detected presence or a detected absence of a leak by the leak detector.
47. A control system according to claim 37 , wherein the simulated signal comprises a simulated reproduction of a waveform emitted by a properly or an improperly operating, or a failed, fan or pump.
48. A control system according to claim 37 , wherein the electrical coupling comprises an electrical current for powering the pump, a PWM signal for controlling the pump, or an FG signal for monitoring operation of the pump.