摘要:
The present invention provides a sequencing control strategy for environmental system controllers that takes better advantage of the capabilities of the system elements to enhance performance and reduce operating costs. A state machine controller is implemented by employing digital technology which enables greater accuracy in monitoring system performance and performing diagnostics. This control modality also provides greater tolerance of faults by permitting automatic reconfiguration of the control strategy so as to be independent of malfunctioning components.
摘要:
A method is disclosed for programming and executing a state machine control program represented as a diagram in an HVAC controller. The diagram is converted to tabular data which is entered into one or more spreadsheet pages. The tabular data includes the defined output states, the defined input states and defined transition states, whereby a given output state and a given set of inputs will cause transition to a next output state. The tabular data is translated, through execution of a routine in a macro-instruction language, into a plurality of data structures for downloading into a finite state machine object data structure in the controller, where it will be acted upon by an object-oriented execution module, referred to as a class execute method, which is also present in the controller.
摘要:
The present invention provides a sequencing control strategy for environmental system controllers that takes better advantage of the capabilities of the system elements to enhance performance and reduce operating costs. Digital controller technology is included and operates in accordance with a state transition diagram clarifying conditions that must exist for the environmental controller to switch from one mode of operation to another (e.g., from a cooling mode with dampers set at the minimum position to a cooling mode with the dampers modulating to reduce the energy used for mechanical cooling). Several controllers, or a single controller operating on several sets of control parameters, sequentially operate in accordance with transition data and system performance characteristics for controlling system operation.
摘要:
A feedback controller configured to automatically tune a control system by determining proportional gain, integral time and/or derivative time control parameters based on estimates of process time delay, process time constant and process gain values which are monitored by the feedback controller. The feedback controller further determines control limits for estimating the process time delay based on the resolution of the sampled values of the process output and the standard deviation of the process output during the initial steady-state condition. The feedback controller also estimates characteristic areas for a first-order response based on a first-order plus time-delay model to determine process time constant and process gain values. These process time constant, process gain and process delay estimates are translated into proportional gain, integral time and/or derivative time control parameters based on design relations of the particular feedback controller.
摘要:
The present invention provides a sequencing control strategy for environmental system controllers that takes better advantage of the capabilities of the system elements to enhance performance and reduce operating costs. Digital controller technology is included and operates in accordance with a state transition diagram clarifying conditions that must exist for the environmental controller to switch from one mode of operation to another (e.g., from a cooling mode with dampers set at the minimum position to a cooling mode with the dampers modulating to reduce the energy used for mechanical cooling). Several a controllers, or a single controller operating on several sets of control parameters, sequentially operate in accordance with transition data and system performance characteristics for controlling system operation.
摘要:
A networked system having a wide variety of applications and particularly applicable to facilities management systems has multiple levels of software in processing nodes. The levels include a "features" processing level which communicates requests for data to a software object level containing databases of processes and attributes and database managers. The database managers in the software object level operate to provide data to the high level features in the same format. The software object level communicates with a hardware object level which also contains databases and database managers to mask differences between operational hardware units. By categorizing operational units by type, additional units of a known type can be added with only low level hardware object database changes. Adding units of a new type is facilitated by software changes confined to the lower level hardware and software objects, avoiding software changes at high level features. Individual software objects are tailored for typical types of inputs and output devices encountered by facilities management systems. Universal drive circuitry also provides applicability to a broad range of devices. Nodes store restoration characteristics of loads controlled by the nodes. After being shed to limit energy consumption, software local to the node restores the loads under predefined circumstances independently of the load shed commands to achieve distributed load management.
摘要:
A network system having a wide variety of applications and particularly applicable to facilities management systems includes network controllers which continuously process data related to building and industrial, environmental, security and other automated system controls. Each network controller has a network address indicative of a communication link to which the network controller is connected, a local address and a node drop ID to determine whether the network controller is a configured or non-configured device. Data stored in an archive device is downloaded to a destination network controller in the absence of a routing table in the destination network controller by transmitting a download request message from the archive device to an intermediate network controller with a routing table. The intermediate network controller assumes control of the download request by transmitting the message to the destination controller. The destination controller acknowledges receipt of the message by transmitting an acknowledge message back to the intermediate network controller, which passes the acknowledge message to the archive device in accordance with the routing information stored in the intermediate network controller. Thus, as certain network controllers are connected, disconnected or disabled during the operation of the network, the control of a process is not interrupted. Additionally, the network controllers are not configured to store large amounts of routing data because a path to a device can be established through other controllers with routing information.
摘要:
A networked system having a wide variety of applications and particularly applicable to facilities management systems has multiple levels of software in processing nodes. The levels include a "features" processing level which communicates requests for data to a software object level containing databases of processes and attributes and database managers. The database managers in the software object level operate to provide data to the high level features in the same format. The software object level communicates with a hardware object level which also contains databases and database managers to mask differences between operational hardware units. By categorizing operational units by type, additional units of a known type can be added with only low level hardware object database changes. Adding units of a new type is facilitated by software changes confined to the lower level hardware and software objects, avoiding software changes at high level features. Individual software objects are tailored for typical types of inputs and output devices encountered by facilities management systems. Universal drive circuitry also provides applicability to a broad range of devices. In each node a time stamp indicates the most recent update of the node's data base. Periodically each node transmits its time stamp. When a node receives a time stamp later than its own, the receiving node requests the transmitting node to transmit its data base to update the receiving node with the earlier time stamp.
摘要:
A networked system having a wide variety of applications and particularly applicable to facilities management systems has multiple levels of software in processing nodes. The levels include a "features" processing level which communicates requests for data to a software object level containing databases of processes and attributes and database managers. The database managers in the software object level operate to provide data to the high level features in the same format. The software object level communicates with a hardware object level which also contains databases and database managers to mask differences between operational hardware units. By categorizing operational units by type, additional units of a known type can be added with only low level hardware object database changes. Adding units of a new type is facilitated by software changes confined to the lower level hardware and software objects, avoiding software changes at high level features. Individual software objects are tailored for typical types of inputs and output devices encountered by facilities management systems. Universal drive circuitry also provides applicability to a broad range of devices.
摘要:
A networked system having a wide variety of applications and particularly applicable to facilities management systems has multiple levels of software in processing nodes. The levels include a "features" processing level which communicates requests for data to a software object level containing databases of processes and attributes and database managers. The database managers in the software object level operate to provide data to the high level features in the same format. The software object level communicates with a hardware object level which also contains databases and database managers to mask differences between operational hardware units. By categorizing operational units by type, additional units of a known type can be added with only low level hardware object database changes. Adding units of a new type is facilitated by software changes confined to the lower level hardware and software objects, avoiding software changes at high level features. Individual software objects are tailored for typical types of inputs and output devices encountered by facilities management systems. Universal drive circuitry also provides applicability to a broad range of devices. An optical isolator is connected between signal line outputs from a node and a line driver connected to a pair of lines on a bus. Similarly, an optical isolator is connected between signal line receiving inputs and a line receiver. The signal lines can be biased to predetermined levels to reduce node sensitivity to noise.