Hart Communication Foundation

Fieldcomm Group, Inc.

Dust Networks, Inc.

Wallace A Pratt, Jr

Mark J Nixon

Eric Darrell Rotvold

Tomas Lennvall

Robin S Pramanik

Terrence L Blevins

Yuri Zats

Frederick R Enns

Thomas L Phinney

Ronald Edgar Ham

Daraius K Hathiram

Mark M Okamura

Chuck Middleton

Aaron C Jones

Tomas P Lennvall

Rick Enns

A digital safety lock of a field device or other process plant equipment activates in response to receiving a request from a locking party, thereby placing the device into a locked mode. While the device is in the locked mode, only the locking party may perform maintenance activities on, or otherwise functionally control, the device. While locked, the device may provide an indication of the locking party to any other device or application attempting to access or control the locked device. Other devices, applications, and users may communicate with the locking party or locking party device to request that the device be unlocked and/or to request the corresponding digital safety lock key. Upon the device receiving the correct digital safety lock key, the digital safety lock may be deactivated, and the device may enter into an unlocked state if no other digital safety locks remain activated for the device.

Digital safety locks in industrial process plants

A system and method of performing communications over a communications network that uses a communication protocol having multiple different versions, provides for backwards compatibility when devices that support a higher or more secure version of the communication protocol are added to a network having devices that only support a lower or less secure version of the communication protocol. The system and method includes a technique of negotiating and establishing security procedures to be implemented in a communication connection between two devices on the network based on initial session request messages that indicate the version of the communication protocol supported by one or both of the devices. This system and method enable higher and lower protocol version devices (i.e., devices that conform to or that use the same communication protocol but that have different versions of the protocol installed therein) to communicate with one another in the most secure manner, thereby making higher version devices added to a network backward compatible with lower version devices already within the network.

Security negotiations between different versioned protocol devices to enable backward compatibility

A method of efficiently operating a wireless communication network in a process control environment, such that the wireless communication network includes a plurality of field devices, includes defining a communication protocol for supporting wireless communications between pairs of the plurality of field devices, including providing a set of protocol commands, transferring process control data from at least some of the plurality of field devices using a first subset of the set of protocol commands of the communication protocol, and transferring network management data to at least some of the plurality of field devices using a second subset of the set of protocol commands of the communication protocol.

Support for network management and device communications in a wireless network

A method of routing a data packet between a first node and a second node on a communication network includes defining a first graph through the first node and the second node and zero or more intermediate nodes, associating several nodes which belong to the communication network with the first graph, associating a first unique graph identifier with the first graph and providing at least partial definitions of the first graph and the first unique identifier to at least some of the nodes associated with the first graph. The method then sends data packet with the graph identifier from the first node, and directs the data packet to the second node via the zero or more intermediate nodes using the graph identifier. This method may include forwarding the packet to a neighbor node of an intermediate node if the intermediate node and the neighbor node are nodes associated with the first graph and if the intermediate node and the neighbor node are connected by at least one direct communication connection.

Routing packets on a network using directed graphs

A mesh communication network for use in, for example, process control plants includes a plurality of network devices transmitting and receiving data according to a network schedule defined as a set of concurrent overlapping superframes, and along a set of graphs defining communication paths between pairs of network devices. A network manager residing in or outside the communication network develops a routing scheme for the network by analyzing the topology of the network and defining a set of graphs for use in routing or transmitting data between various nodes of the network, each graph including one or more communication paths between pairs of network devices. Concurrently or consequently, the network manager defines the network schedule in view of at least transmission requirements, power availability, and signal quality at each network device. If desired, the network manager may begin to define the network schedule upon completing the definition of the graphs of the communication network, so that the network manager may define the network schedule in view both the defined graphs and the transmission, power, etc. parameters associated with each network device.

Increasing reliability and reducing latency in a wireless network

A method of providing a wireless extension to a plant automation network connected to a plurality of wired devices, each wired device performing a process control function, includes connecting a plurality of wireless devices to the plant automation network, each of the plurality of wireless devices adapted to communicate with at least another one of the plurality of wireless devices via at least one respective wireless connection; and providing access to each of the plurality of wireless devices from a host disposed in the plant automation network, such that the host accesses the plurality of wired devices and the plurality of wireless devices using a common communication scheme.

Combined wired and wireless communications with field devices in a process control environment

A method of enhancing security in a wireless mesh communication network operating in a process control environment and including a plurality of wireless network devices includes processing a join request from a wireless device wishing to join the wireless mesh communication network, providing a limited network functionality to the wireless device if the join request is granted, requesting a complete approval of the wireless device; and granting a full network functionality to the wireless device if the complete approval of the wireless device is received.

Enhancing security in a wireless network

A method for synchronizing communications in wireless mesh network operating in a process control environment and including a plurality of network devices includes defining a communication timeslot of a predetermined duration, wherein each of the plurality of network devices transmits or receives data only within the communication timeslot generating a network schedule including at least one superframe having repeating superframe cycles each having a number of communication timeslots sequentially numbered relative to a beginning of each cycle, the number of communication timeslots defining a length of the at least one superframe, maintaining an absolute slot number indicative of a number of communication timeslots scheduled since a start time of the wireless network, synchronizing each of the plurality of network devices with respect to a timing of an individual communication timeslot, and synchronizing each of the plurality of network devices with the network schedule based on the absolute slot number.

Synchronizing timeslots in a wireless communication protocol

A method of providing a wireless extension to a wired protocol for transferring data to and from a field device operating in a process control environment via a wired connection, wherein the wired protocol and the wireless extension to the wired protocol have at least one protocol layer in common includes associating a unique address consistent with an addressing scheme of the wired protocol with each of a plurality of wireless devices operating in the process control environment and forming a wireless network, such that a data packet is routed between two of the plurality of wireless devices based on the unique address; associating a network identifier with the plurality of wireless devices; forming, for each of the plurality of wireless devices, a global address including the respective unique address and the network identifier in accordance with a second addressing scheme; and providing access to an external host operating outside the wireless network to each of the plurality of wireless devices based on the global address associated with the wireless device specified at the external host.

Efficient addressing in wireless hart protocol

A wireless gateway for use in a process control environment includes a wireless interface for communicating with a first wireless network using a first wireless communication protocol, such that the wireless network includes a plurality of field devices operating in the process control environment. The wireless gateway further includes a host interface for communicating with an external host disposed outside the wireless network using a second communication protocol and a protocol translator to enable an exchange of data between the first interface and the second interface.

Wireless gateway in a process control environment supporting a wireless communication protocol

A packet controller for simultaneous processing of data packets transmitted via a plurality of communication channels includes a plurality of inputs to receive a respective plurality of signals, such that each of the plurality of signals is indicative of a presence of a data packet on a respective one of the plurality of communication channels, a clock source to supply a periodic clock signal, a plurality of independent processing modules coupled to the respective plurality of inputs to simultaneously process the plurality of signals, such that each of the plurality of independent processing modules implements a respective state machine driven by the periodic clock signal to process the respective signal independently of every other one of the plurality of processing modules, and an output to transmit an output signal indicative of a presence of at least one data packet on one or more of the plurality of communication channels.

Simultaneous data packet processing

A method of routing data in a mesh communication network including a plurality of network devices and operating in a process control environment, including assigning one of a plurality of priority levels associated with the communication network to a data packet, sending the data packet from a source network device included in the plurality of network devices to a destination network device included in the plurality of network devices, and routing the data packet to a destination network device via at least one intermediate network device included in the plurality of network devices. The act of routing includes comparing, at each intermediate network device, the priority level of the data packet to a priority mask of the intermediate network device, and modifying at least one of scheduling or routing of the data packet if the priority level of the data packet is not associated with the priority mask of the intermediate network device.

Priority-based scheduling and routing in a wireless network

A method of scheduling communications in a multi-node wireless mesh network which has a first network device and a second network device includes defining a communication timeslot of a predetermined duration, defining a first superframe having a repeating superframe cycle including a first number of the communication timeslots, defining a second superframe having a repeating superframe cycle including a second number of the communication timeslots, aligning the first superframe with the second superframe, so that one of the timeslots of the first superframe begins simultaneously with one of the timeslots of the second superframe, and associating the first and the second superframes with a network schedule, so that the first network device and the second network device transmit data according to the network schedule.

Growing community of inventors

Pflugerville, TX, United States of America

Wallace A Pratt, Jr