Plant floor event protocol and schema
A method is provided for managing information on a plant floor, and includes recording a definition file, such as an extended markup language (XML) schema, in a source device, and generating a plant floor event (PFE) message as a bit array or string array. The PFE message transfers from the source device to a host device or other appliance. The method then includes executing at least one action in response to the PFE message. A system is also provided for managing information on a plant floor, and includes a PLC that generates a PFE message as a bit or string array. The system includes an alarm database, and automatically propagates the PFE message upward from the PLC to a host device, such as a server, a database, or a display device, and automatically executes an action in response to the PFE message.
1 . A method for managing information on a plant floor, the method comprising:
recording a schema in a first memory location of a source device;
generating a first plant floor event (PFE) message corresponding to at least one of an internal process variable and an external input variable, wherein the first PFE message is a set of information having a structure defined by the schema;
automatically transferring the first PFE message from the source device to a second memory location of a host device when at least one value of the first PFE message changes from a known value; and
executing at least one action in response to the first PFE message.
2 . The method of claim 1 , wherein executing at least one action includes at least one of transmitting a second PFE message from the host device to the source device and activating an alarm.
3 . The method of claim 2 , wherein at least one of the first PFE message and the second PFE message is selected from the group consisting of a production count, an alarm status, a process status, a progress indicator, a device configuration status, and a reconfiguration command.
4 . The method of claim 1 , wherein the source device is configured as a first programmable logic controller (PLC) having a human-machine interface (HMI).
5 . The method of claim 1 , further comprising determining whether the schema is a known schema stored within the host device; and
automatically recording the schema within the host device when the schema is not among the known schema.
6 . The method of claim 1 , wherein recording the schema includes recording an extended markup language (XML) schema.
7 . The method of claim 1 , wherein generating a first PFE message includes encoding the set of information as one of a bit array and a string array.
8 . The method of claim 1 , wherein the host device is selected from the group consisting of a server, a data acquisition (DAQ) system, an information database, a PLC device, and a display device.
9 . The method of claim 1 , wherein generating the first PFE message includes assigning a code uniquely identifying an event type of the first PFE message.
10 . The method of claim 9 , wherein the event type is selected from the group consisting of an electronic handshake, an electronic heartbeat, an IP address, a reset event, a time synchronization event, a resource event, an alarm event, a counter event, a record event, a schema event, and an ad-hoc event.
11 . The method of claim 1 , wherein executing at least one includes altering a configuration of at least one of the source device and the host device.
12 . A method for managing information on a plant floor using a plurality of computing devices, the method comprising:
recording an extended markup language (XML) schema in a first one of the plurality of computing devices;
encoding a plurality of different information pieces as one of a bit array and a string array having a structure defining a first plant floor event (PFE) message, the first PFE message having a structure defined by the XML schema;
automatically transferring the information pieces from the first computing device to a second one of the plurality of computing devices without hardcoding the second computing device, to thereby render the method self-configuring;
automatically transferring the XML schema from the first computing device to the second computing device when the XML schema is an unknown schema without providing a pre-established fixed packet structure in the second computing system, to thereby render the method self-describing; and
executing at least one action in response to the first PFE message.
13 . The method of claim 12 , wherein executing at least one action includes at least one of transmitting a second PFE message from the second computing device to the first computing device and activating an alarm.
14 . The method of claim 13 , wherein each the first and second computing devices is selected from the group consisting of a programmable logic controller (PLC), a portable digital assistant (PDA), a human-machine interface (HMI), a database, an electronic appliance, and a Turing machine.
15 . The method of claim 14 , further comprising:
defining an unknown PFE message in the first computing device, the unknown PFE message being one of a new PFE message and a modified PFE message; and
automatically mapping the unknown PFE message from the first computing device to a second memory location of the second computing device and to a third memory location of a third computing device in response to the unknown PFE message.
16 . The method of claim 14 , wherein executing at least one action in response to the first PFE message includes at least one of recording an alarm in an alarm database and transmitting a message between the second computing device and the first computing device.
17 . The method of claim 14 , wherein executing at least one action in response to the PFE message includes activating a display device.
18 . An information management system for use on a plant floor, the system comprising:
a programmable logic controller (PLC) having a definition file for defining a data structure for a plant floor event (PFE) message, the PLC being configured for generating the PFE message in response to at least one of an internal process variable and an external input variable;
an alarm database in electrical communication with the PLC, the alarm database being configured for storing a plurality of different alarm codes; and
a host device in electrical communication with the PLC;
wherein the system is self-configurable by being adapted for automatically propagating the PFE message from the PLC to the host device, and is self-defining by being adapted for automatically propagating a change in the definition file to the host device; and
wherein the system is configured for executing at least one action in response to the PFE message.
19 . The system of claim 18 , wherein the host device is selected from the group consisting of another PLC, a server, data acquisition system, a storage device, and a display device.
20 . The system of claim 18 , wherein the at least one action is selected from the group consisting transmitting a second PFE message from the host device to the PLC device and activating an alarm.