System and method for serving isolated sensors in building control system

Abstract

The present disclosure relates to systems and methods for serving isolated sensors in a building control system. Each non-isolated RF sensor of the plurality of non-isolated RF sensors may be assigned to a corresponding communication slot of the plurality of communication slots. An emergency message and a non-emergency message are received from each of the non-isolated RF sensors. One or more emergency messages and non-emergency messages are sent to a remote device via a building control network. Each of the isolated RF sensors is assigned to a corresponding emergency communication slot of the plurality of emergency communication slots. An emergency message is received from each of the isolated RF sensors allocated to one of the emergency communication slots, but a non-emergency message is not received. One or more emergency messages are transmitted to the remote device, the one or more emergency messages based at least in part on emergency messages received from each of the one or more isolated RF sensors allocated to one of the plurality of emergency communication slots.

Description

Technical Field

[0001] The present disclosure relates generally to methods and systems for communications in a building control system, and more particularly to methods and systems for communicating with isolated sensors in a building control system. Background Art

[0002] Building control systems, such as security systems, fire safety systems, and HVAC (heating, ventilation, and air conditioning) systems, may include a large number of individual building control devices that communicate wirelessly. In some cases, communications with an individual building control device may fail, potentially orphaning the building control device and preventing the orphaned building control device from providing critical alarms or other events to the building control system. Methods and systems for establishing emergency communications with orphaned building control devices are desirable. Summary of the invention

[0003] The present disclosure generally relates to methods and systems for communication in building control systems, and more specifically to methods and systems for communicating with isolated sensors in building control systems. An example can be found in a method for operating a wireless (e.g., radio frequency) node of a building control network to serve non-isolated and isolated wireless (e.g., RF) sensors. The illustrative method includes assigning each of a plurality of non-isolated RF sensors to a corresponding communication slot in a plurality of communication slots of an RF node. During operation, emergency messages and non-emergency messages are received from each of a plurality of non-isolated RF sensors assigned to one of a plurality of communication slots of the RF node. One or more emergency messages and non-emergency messages are sent from the RF node to a remote device via the building control network, wherein the one or more emergency messages and non-emergency messages are based at least in part on emergency messages and non-emergency messages received from each of a plurality of non-isolated RF sensors assigned to one of a plurality of communication slots of the RF node.

[0004] Each of the one or more isolated RF sensors is assigned to a corresponding emergency communication timeslot of a plurality of emergency communication timeslots of the RF node. In some cases, the number of emergency communication timeslots is separate from the number of communication timeslots used by non-isolated RF sensors. Emergency messages are received from each of the one or more isolated RF sensors assigned to one of the plurality of emergency communication timeslots, but non-emergency messages are not received. One or more emergency messages are sent from the RF node to a remote device via a building control network, wherein the one or more emergency messages are based at least in part on the emergency messages received from each of the one or more isolated RF sensors assigned to one of the plurality of emergency communication timeslots.

[0005] Another example can be found in a building control system. The building control system includes a controller, two or more RF nodes operably coupled to the controller, and a plurality of RF sensors, each of which is operably coupled to a corresponding RF node in the two or more RF nodes. Each of the plurality of RF sensors is assigned to a corresponding communication slot in a plurality of communication slots of the corresponding RF node. The controller is configured to: determine when one of the plurality of RF sensors is lost; and when a communication slot is available, instruct another RF node in the two or more RF nodes to establish communication with the lost RF sensor by assigning the lost RF sensor to one of the plurality of communication slots of another RF node. When the communication slot of the other RF node is not available, the controller is configured to send the sensor ID of the lost RF sensor to an emergency whitelist stored by each of the two or more RF nodes, and the lost RF sensor is now considered to be an isolated RF sensor. One of the two or more RF nodes is configured to: read the emergency whitelist and assign the isolated RF sensor to a corresponding emergency communication time slot of a plurality of emergency communication time slots of the corresponding RF node (if available); and notify a controller that the isolated RF sensor has been assigned to a corresponding emergency communication time slot of a plurality of emergency communication time slots of the corresponding RF node. Then, the controller is configured to remove the isolated RF sensor from the emergency whitelist of another RF node of the two or more RF nodes. The assigned RF node is configured to: receive a message from the isolated RF sensor; and send one or more messages to the controller, wherein the one or more messages are based at least in part on the message received from the isolated RF sensor.

[0006] Another example may be found in a non-transitory computer-readable medium storing instructions that, when executed by one or more processors of an RF node on a building control network, cause the one or more processors to assign each of a plurality of non-isolated RF sensors to a corresponding communication slot in a plurality of communication slots of the RF node. Cause the one or more processors to receive emergency messages and non-emergency messages from each of a plurality of non-isolated RF sensors assigned to one of a plurality of communication slots of the RF node. Cause the one or more processors to send one or more emergency messages and non-emergency messages to a remote device via the building control network, wherein the one or more emergency messages and non-emergency messages are at least partially based on emergency messages and non-emergency messages received from each of a plurality of non-isolated RF sensors assigned to one of a plurality of communication slots of the RF node. Cause the one or more processors to assign each of the one or more isolated RF sensors to a corresponding emergency communication slot in a plurality of emergency communication slots of the RF node. Cause the one or more processors to receive emergency messages, but not non-emergency messages, from each of the one or more isolated RF sensors assigned to one of a plurality of emergency communication slots of the RF node. Cause one or more processors to send one or more emergency messages to a remote device via a building control network, wherein the one or more emergency messages are based at least in part on an emergency message received from each of one or more isolated RF sensors in one of a plurality of emergency communication time slots assigned to the RF node.

[0007] The above summary is provided to facilitate understanding of some innovative features unique to the present disclosure, but is not intended to be a complete description. A comprehensive understanding of the present disclosure can be obtained by viewing the entire specification, claims, drawings and abstract as a whole. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] The present disclosure may be more fully understood by considering the following description of various examples in conjunction with the accompanying drawings, in which:

[0009] Figure 1 is a schematic block diagram illustrating an exemplary building control system;

[0010] Figure 2A and Figure 2B are flowcharts that collectively illustrate illustrative methods; and

[0011] Figure 3 is a flow chart illustrating an exemplary method.

[0012] Although the present disclosure is subject to various modifications and alternative forms, the details thereof have been shown by way of example in the accompanying drawings and will be described in detail. However, it should be understood that it is not intended to limit the present disclosure to the specific examples described. On the contrary, it is intended to cover all modifications, equivalents and alternatives that fall within the essence and scope of the present disclosure. DETAILED DESCRIPTION

[0013] The following description should be read with reference to the accompanying drawings, in which similar elements in different drawings are numbered in the same manner. The accompanying drawings are not necessarily drawn to scale, and they depict examples that are not intended to limit the scope of the present disclosure. Although examples of various elements are shown, those skilled in the art will recognize that many of the examples provided have suitable alternatives that can be utilized.

[0014] It is assumed herein that all numbers are modified by the term "about" unless the content clearly dictates otherwise. The recitation of numerical ranges by endpoints includes all numbers subsumed within that range (eg, 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4, and 5).

[0015] As used in this specification and the appended claims, the singular forms "a," "an," and "the" include plural referents unless the content clearly dictates otherwise. As used in this specification and the appended claims, the term "or" is generally employed in its sense including "and / or" unless the content clearly dictates otherwise.

[0016] It should be noted that references to "one embodiment", "some embodiments", "other embodiments", etc. in the specification indicate that the described embodiments may include a particular feature, structure, or characteristic, but every embodiment may not necessarily include the particular feature, structure, or characteristic. Moreover, these phrases do not necessarily refer to the same embodiment. In addition, when a particular feature, structure, or characteristic is described in conjunction with one embodiment, it is contemplated that the feature, structure, or characteristic is described in conjunction with one embodiment, and it is contemplated that the feature, structure, or characteristic may be applied to other embodiments regardless of whether explicitly described, unless otherwise clearly stated.

[0017] Figure 11 is a schematic block diagram illustrating an exemplary building control system 10. The exemplary building control system 10 may generally represent any one of a security system, a lighting system, a heating, ventilation and air conditioning (HVAC) system, etc. The exemplary building control system 10 includes a remote device 12. In some cases, the remote device 12 may be a control panel. In some cases, the remote device 12 may include a controller 14 that controls the operation of at least some components of the building control system 10. In some cases, the controller 14 is the remote device 12. The building control system 10 includes two or more RF nodes 16, which are labeled 16a, 16b, and 16c, respectively. This is merely exemplary, as the building control system 10 may include any number of RF nodes 16. In some cases, at least some of the RF nodes 16 may be RF routers or gateways. In some cases, at least some of the RF nodes 16 may be RF routers within a security system.

[0018] Each of the RF nodes 16 may include several communication time slots, through which the RF node 16 can communicate with the corresponding sensor. In some cases, each of the RF nodes 16 may include several primary communication channels (e.g., time slots) and several secondary communication channels (e.g., time slots). In some cases, each of the RF nodes 16 may be configured to also provide several emergency communication channels (e.g., time slots), even when all primary communication channels and all secondary communication channels (e.g., time slots) for a particular RF node 16 are being used, the several emergency communication channels can still be relied on to communicate with the particular RF node 16. As an example, each RF node 16 may include a total of 24 primary communication channels, 24 secondary communication channels, and 6 emergency communication channels. This is merely illustrative, as the RF node 16 may have any number of primary communication channels, any number of secondary communication channels, and any number of emergency communication channels.

[0019] The building control system 10 includes a plurality of RF sensors, including RF sensors 18, labeled 18a, 18b to 18n, respectively; RF sensors, labeled 20a, 20b to 20n, respectively; and RF sensors 22, labeled 22a, 22b to 22n, respectively. Each of the RF sensors 18, 20, and 22 may be assigned to a corresponding RF node in the RF nodes 16. As an example, the RF sensors 18 may each be assigned to a specific communication time slot of the RF node 16a, the RF sensors 20 may each be assigned to a specific communication time slot of the RF node 16b, and the RF sensors 22 may each be assigned to a specific communication time slot of the RF node 16c. In some cases, at least some of the RF sensors 18, 20, and 22 may be wireless security sensors, such as motion sensors, door sensors, window sensors, glass breakage detectors, and the like. The RF nodes 16 each communicate with the remote device 12 (and / or the controller 14) via a building control network 23. The communication network may be a wired network, a wireless network, or a combination of wired and wireless.

[0020] In some cases, wireless communication within the building control system 10 may sometimes fail. For example, one of the RF nodes 16 may become disabled or otherwise inoperative. Temporary events may interfere with wireless communication. As an example, operation of an unshielded electric motor may cause a temporary interruption of wireless communication between at least some devices within the building control system 10. In some cases, the building control system 10 may be configured to handle problems that may arise in wireless communication between devices. In some cases, a communication cable of the building control system may be disconnected or damaged.

[0021] In some cases, the controller 14 may be configured to determine when one of the plurality of RF sensors 18, 20, and 22 is lost, and when a communication slot (e.g., a secondary communication slot) is available, instruct another RF node of the two or more RF nodes 16 to establish communication with the lost RF sensor 18, 20, 22 by assigning the lost RF sensor 18, 20, 22 to one of the plurality of communication slots (e.g., a secondary communication slot). In some cases, the RF node 16 having the highest signal strength and / or the highest signal-to-noise ratio (SNR) of the lost RF sensor 18, 20, 22 is selected to assign the lost RF sensor 18, 20, 22 to one of the plurality of communication slots (e.g., a secondary communication slot) when the communication slot (e.g., a secondary communication slot) is available. When none of the RF nodes has an available communication slot (e.g., a secondary communication slot), the controller 14 is configured to add the sensor ID of the missing RF sensor 18, 20, 22 to an emergency whitelist sent to each of the two or more RF nodes 16, and the missing RF sensor 18, 20, 22 may be considered an orphan RF sensor.

[0022] The RF nodes 16 are configured to read the emergency whitelist, and one of the RF nodes 16 is configured to assign the isolated RF sensor to a corresponding emergency communication time slot (if available) in a plurality of emergency communication time slots of the corresponding RF node 16. In some cases, the RF node 16 having the highest signal strength and / or the highest signal-to-noise ratio (SNR) of the isolated RF sensor is selected to assign the isolated RF sensor to one of the emergency time slots when the emergency time slot is available. The RF node that assigns the isolated RF sensor to one of its plurality of emergency time slots is configured to notify the controller 14 that the isolated RF sensor has been assigned to the corresponding emergency communication time slot in the plurality of emergency communication time slots of the corresponding RF node 16. In response, the controller 14 is configured to remove the isolated RF sensor from the emergency whitelist of another RF node of the two or more RF nodes 16. The RF node that assigns the isolated RF sensor to one of its plurality of emergency time slots is configured to: receive a message from the isolated RF sensor; and send one or more messages to the controller 14, wherein the one or more messages are based at least in part on the message received from the isolated RF sensor. In some cases, an RF node that assigns an isolated RF sensor to one of its multiple emergency time slots receives emergency messages from the isolated RF sensor but does not receive non-emergency messages. This helps reduce the load on the RF node, but allows the emergency message to be transmitted from the isolated RF node to the remote device 12.

[0023] In some cases, the RF sensors 18, 20, 22 may be lost due to a failure of the RF node 16 to which the RF sensors 18, 20, 22 were assigned, and the RF node 16 may subsequently be restored. In this case, the controller 14 and / or the restored RF node 16 may be configured such that the orphan RF sensor is assigned to a corresponding communication slot of a plurality of communication slots of the restored RF node 16. In some cases, the controller 14 and / or the restored RF node 16 may be configured to remove the orphan RF sensor from the emergency whitelist of all of the two or more RF nodes 16.

[0024] Figure 2A and Figure 2B 2 is a flow chart collectively illustrating an exemplary method 24 for operating an RF node of a building control network to serve non-isolated and isolated RF sensors. As an example, the RF node may be an RF router or RF gateway of a security system of a building, and the non-isolated RF sensor and the isolated RF sensor may be security system sensors.

[0025] The exemplary method 24 includes assigning each of the plurality of non-isolated RF sensors to a corresponding communication slot in the plurality of communication slots, as indicated at block 26. In some cases, the plurality of communication slots may include a set of primary communication slots and a set of secondary communication slots, and the method 24 may also include assigning each of the plurality of non-isolated RF sensors to a corresponding primary communication slot in a set of primary communication slots of another RF node of the building control network to one of the secondary communication slots of the RF node. Each RF node may also include a number of emergency communication slots. The number of primary communication slots and secondary communication slots of the RF node may exceed the number of emergency communication slots of the RF node. In some cases, the RF node may be an RF router, and the remote device may include a controller.

[0026] Emergency messages and non-emergency messages are received from each of a plurality of non-isolated RF sensors assigned to a communication slot (e.g., a primary communication slot or a secondary communication slot) of a plurality of communication slots, as indicated at block 28. For example, the emergency message may include one or more of an alarm message and a sensor tamper message. In some cases, the non-emergency message may include one or more of a periodic regulatory message (e.g., a supervision message) and a low battery message. Additional emergency messages and non-emergency messages are contemplated. One or more emergency messages and non-emergency messages are sent to the remote device 12 via the building control network 23, wherein the one or more emergency messages and non-emergency messages are based at least in part on the emergency messages and non-emergency messages received from each of a plurality of non-isolated RF sensors assigned to a communication slot (e.g., a primary communication slot or a secondary communication slot) of a plurality of communication slots, as indicated at block 30.

[0027] Each of the one or more isolated RF sensors is assigned to a corresponding emergency communication timeslot of the plurality of emergency communication timeslots, as indicated at block 32. Emergency messages are received from each of the one or more isolated RF sensors assigned to one of the plurality of emergency communication timeslots, but non-emergency messages are not received, as indicated at block 34. One or more emergency messages are sent to the remote device 12 via the building control network 23, wherein the one or more emergency messages are based at least in part on the emergency messages received from each of the one or more isolated RF sensors assigned to one of the plurality of emergency communication timeslots, as indicated at block 36. In some cases, the method 24 may include determining when a first of the isolated RF sensors assigned to a first of the plurality of emergency communication timeslots is no longer an isolated RF sensor, and in response, releasing the first of the plurality of emergency communication timeslots for use by another of the one or more isolated RF sensors, as indicated at block 38.

[0028] In some cases, and Figure 2B Continuing above, method 24 may include, after receiving one or more emergency messages from a first isolated RF sensor of the isolated RF sensors assigned to the first emergency communication time slot of the plurality of emergency communication time slots, releasing the first emergency communication time slot of the plurality of emergency communication time slots for use by another isolated RF sensor of the one or more isolated RF sensors, as indicated at block 40. When the isolated RF sensor again has an emergency message, the isolated RF sensor may request to be assigned one of the plurality of emergency communication time slots.

[0029] In some cases, method 24 may include determining an RSSI value for each of the two or more isolated RF sensors, including determining the isolated RF sensor having the highest RSSI value, as indicated at block 42. The isolated RF sensor having the highest RSSI value may be assigned to a corresponding emergency communication time slot of the plurality of emergency communication time slots, as indicated at block 44.

[0030] In some cases, the method 24 may include receiving an RF sensor whitelist from a remote device, as indicated at block 46. A determination may be made as to whether the RF sensor is on the RF sensor whitelist, and only if it is determined that the RF sensor is on the RF sensor whitelist, the RF sensor may be assigned to a corresponding communication slot in a plurality of communication slots, as indicated at block 48. In some cases, the method 24 may include receiving an emergency whitelist of orphan RF sensors from a remote device, as indicated at block 50. A determination may be made as to whether the orphan RF sensor is on the emergency whitelist, and only if it is determined that the orphan RF sensor is on the emergency whitelist, the orphan RF sensor may be assigned to a corresponding emergency communication slot in a plurality of emergency communication slots, as indicated at block 52. This may help ensure that only authorized devices are allowed to communicate on the building control network. In some cases, the emergency whitelist of orphan RF sensors may not include orphan RF sensors that are assigned to corresponding emergency communication slots in a plurality of emergency communication slots of another RF node of the building control network.

[0031] Figure 3 is a flow chart illustrating an illustrative method 56. The illustrative method 56 begins at a start box 58. Control proceeds to box 60, where monitoring is maintained to find any missing RF sensors. At decision box 62, a determination is made as to whether there are any missing sensors (e.g., because the RF node is offline). If there are no missing RF sensors, control returns to box 60. If there are missing RF sensors, control proceeds to box 64, where any RF nodes with idle secondary communication slots are checked. In this example, each RF node maintains a plurality of primary communication slots, a plurality of secondary communication slots, and a plurality of emergency communication slots. At decision box 66, a determination is made as to whether there are RF nodes that include idle secondary communication slots for missing sensors. If so, control proceeds to box 68, where the missing sensor is assigned to an idle secondary slot of the selected RF node.

[0032] Otherwise, control proceeds to box 70, where the serial number (or other identifier) ​​for the lost sensor is pushed to the emergency whitelist of each RF node. At box 72, once the sensor is about to send the next emergency message (e.g., an alarm), the RSSI signal strength can be used to determine which RF node to assign the sensor to, and then the sensor is assigned to the emergency communication time slot of the selected RF node. The sensor can retain the emergency communication time slot of the selected RF node, while the sensor identifier can be removed from the emergency whitelist of other RF nodes, as indicated at box 74. At decision box 76, a determination is made as to whether the RF node that originally hosted the sensor via the primary communication time slot has been restored. If not, control returns to box 76, where a determination is made as to whether the RF node that originally hosted the sensor via the primary communication time slot has been restored. If yes, control proceeds to decision box 80, where the sensor is assigned to the primary communication time slot of the restored RF node, and the sensor ID is removed from the emergency whitelist of all RF nodes from the RF node.

[0033] Although several exemplary embodiments of the present disclosure have been described in this manner, it will be readily understood by those skilled in the art that other embodiments may be made and used within the scope of the claims appended hereto. However, it should be understood that the present disclosure is in many respects merely illustrative. Details (especially details related to shape, size, arrangement of parts, and exclusion and order of steps) may be changed without exceeding the scope of the present disclosure. Of course, the scope of the present disclosure is defined in the language of the appended claims.

Claims

1. A method for operating an RF node of a building control network to serve non-isolated RF sensors and isolated RF sensors, the method comprising: assigning each non-isolated RF sensor of the plurality of non-isolated RF sensors to a corresponding communication time slot of the plurality of communication time slots; receiving an emergency message and a non-emergency message from each of the plurality of non-isolated RF sensors assigned to one of the plurality of communication time slots; transmitting one or more emergency messages and non-emergency messages to a remote device via the building control network, wherein the one or more emergency messages and non-emergency messages are based at least in part on the emergency message and the non-emergency message received from each of the plurality of non-isolated RF sensors assigned to one of the plurality of communication time slots; assigning each of the one or more isolated RF sensors to a corresponding emergency communication time slot of the plurality of emergency communication time slots; receiving emergency messages but not non-emergency messages from each of the one or more isolated RF sensors assigned to one of the plurality of emergency communication time slots; as well as One or more emergency messages are sent to the remote device via the building control network, wherein the one or more emergency messages are based at least in part on the emergency message received from each of the one or more isolated RF sensors assigned to an emergency communication time slot of the plurality of emergency communication time slots.

2. The method according to claim 1, further comprising: Determining when a first one of the isolated RF sensors that was assigned to a first one of the plurality of emergency communication time slots is no longer an isolated RF sensor, and in response, releasing the first one of the plurality of emergency communication time slots for use by another one of the one or more isolated RF sensors.

3. The method according to claim 1, further comprising: After receiving one or more emergency messages from a first isolated RF sensor among the isolated RF sensors assigned to a first emergency communication time slot among the multiple emergency communication time slots, the first emergency communication time slot among the multiple emergency communication time slots is released for use by another isolated RF sensor among the one or more isolated RF sensors.

4. The method according to claim 1, further comprising: determining an RSSI value for each of two or more of the isolated RF sensors, including determining an isolated RF sensor having a highest RSSI value; as well as The isolated RF sensor having the highest RSSI value is assigned to a corresponding emergency communication time slot of the plurality of emergency communication time slots. The method of claim 1 , wherein the emergency message comprises one or more of an alert message and a sensor tamper message. The method of claim 1 , wherein the non-emergency message comprises one or more of a periodic regulatory message and a low battery message.

7. The method according to claim 1, further comprising: receiving a whitelist of RF sensors from the remote device; as well as A determination is made as to whether an RF sensor is on the RF sensor whitelist, and only if it is determined that the RF sensor is on the RF sensor whitelist, the RF sensor is assigned to the corresponding communication time slot of the plurality of communication time slots.

8. The method according to claim 1, further comprising: receiving an emergency whitelist of orphaned RF sensors from the remote device; as well as A determination is made as to whether an orphan RF sensor is on the emergency whitelist, and only if it is determined that the orphan RF sensor is on the emergency whitelist, the orphan RF sensor is assigned to the corresponding emergency communication timeslot of the plurality of emergency communication timeslots.

9. The method according to claim 8, further comprising: The emergency whitelist of orphan RF sensors does not include an orphan RF sensor that is assigned to a corresponding emergency communication timeslot of a plurality of emergency communication timeslots of another RF node of the building control network.

10. The method of claim 1, wherein the plurality of communication time slots comprises a set of primary communication time slots and a set of secondary communication time slots, the method comprising: Each of a plurality of non-isolated RF sensors previously assigned to a corresponding primary communication timeslot in a set of primary communication timeslots of another RF node of the building control network is assigned to one of the secondary communication timeslots of the RF node.

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