Patent Publication Number: US-11640737-B2

Title: Secure and safe access control

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This is a continuation-in-part application of and claims priority to U.S. patent application Ser. No. 16/901,312 entitled “SECURE AND SAFE ACCESS CONTROL” and filed on Jun. 15, 2020, for Roberto Marques, which is incorporated herein by reference. 
    
    
     BACKGROUND INFORMATION 
     The subject matter disclosed herein relates to secure and safe access control for equipment units. 
     BRIEF DESCRIPTION 
     A method for secure and safe access control is disclosed. The method authenticates, by use of a processor, a user of an equipment unit with a user credential. The method determines an equipment status for the equipment unit. The equipment status includes one of energized and un-energized and one of locked and unlocked. The method determines whether the user is authorized to access the equipment unit with an equipment authorization. The determination that the user is authorized is based on the equipment status. In response to the user being authenticated and authorized to access the equipment unit energized or the user being authorized to access the equipment unit un-energized and the equipment unit being un-energized, the method releases a unit lock for the equipment unit with a unit lock credential and the user credential. 
     An apparatus for secure and safe access control is also disclosed. The apparatus includes a processor and a memory storing code executable by the processor. The processor determines an equipment status for the equipment unit. The equipment status includes one of energized and un-energized and one of locked and unlocked. The processor determines whether the user is authorized to access the equipment unit with an equipment authorization. The determination that the user is authorized is based on the equipment status. In response to the user being authenticated and authorized to access the equipment unit energized or the user being authorized to access the equipment unit un-energized and the equipment unit being un-energized, the processor releases a unit lock for the equipment unit with a unit lock credential and the user credential. 
     A computer program product for secure and safe access control is also disclosed. The computer program product includes a non-transitory computer readable storage medium having program code embodied therein. The program code is readable/executable by a processor. The processor determines an equipment status for the equipment unit. The equipment status includes one of energized and un-energized and one of locked and unlocked. The processor determines whether the user is authorized to access the equipment unit with an equipment authorization. The determination that the user is authorized is based on the equipment status. In response to the user being authenticated and authorized to access the equipment unit energized or the user being authorized to access the equipment unit un-energized and the equipment unit being un-energized, the processor releases a unit lock for the equipment unit with a unit lock credential and the user credential. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       In order that the advantages of the embodiments of the invention will be readily understood, a more particular description of the embodiments briefly described above will be rendered by reference to specific embodiments that are illustrated in the appended drawings. Understanding that these drawings depict only some embodiments and are not therefore to be considered to be limiting of scope, the embodiments will be described and explained with additional specificity and detail through the use of the accompanying drawings, in which: 
         FIG.  1 A  is a schematic block diagram of an access control system according to an embodiment; 
         FIG.  1 B  is a schematic block diagram of an access control system according to an alternate embodiment; 
         FIG.  1 C  is a schematic block diagram of an access control system according to an alternate embodiment; 
         FIG.  1 D  is a schematic block diagram of an access control system according to an alternate embodiment; 
         FIG.  2 A  is a perspective drawing of an equipment unit according to an embodiment; 
         FIG.  2 B  is a perspective drawing of an equipment unit according to an embodiment; 
         FIG.  2 C  is a perspective drawing of a section according to an embodiment; 
         FIG.  2 D  is a perspective drawing of an equipment unit and wire way according to an embodiment; 
         FIG.  2 E  is perspective drawings of a unit lock, padlock, and key according to an embodiment; 
         FIG.  2 F  is a perspective drawing of a unit lock according to an embodiment; 
         FIG.  2 G  is a perspective drawing of a Radio Frequency Identifier (RFID) according to an embodiment; 
         FIG.  2 H  is a drawing of an electronic device according to an embodiment; 
         FIG.  3 A  is a schematic block diagram of access data according to an embodiment; 
         FIG.  3 B  is a schematic block diagram of an equipment record according to an embodiment; 
         FIG.  3 C  is a schematic block diagram of a user record according to embodiment; 
         FIG.  3 D  is a schematic block diagram of equipment authorizations according to an embodiment; 
         FIG.  4 A  is a schematic block diagram of a computer according to an embodiment; 
         FIG.  4 B  is a schematic block diagram of a tag reader according to an embodiment; 
         FIG.  5 A  is a schematic flow chart diagram of a secure access method according to an embodiment; 
         FIG.  5 B  is a schematic flow chart diagram of a unit lock release method according to an embodiment; 
         FIG.  5 C  is a schematic flow chart diagram of a data conversion method according to an embodiment; 
         FIG.  5 D  is a schematic flow chart diagram of a secure access method according to an alternate embodiment; 
         FIG.  6 A  is a schematic block diagram of a lock controller according to an embodiment; and 
         FIG.  6 B  is a schematic block diagram of a unit lock according to an embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     Reference throughout this specification to “one embodiment,” “an embodiment,” or similar language means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment. Thus, appearances of the phrases “in one embodiment,” “in an embodiment,” and similar language throughout this specification may, but do not necessarily, all refer to the same embodiment, but mean “one or more but not all embodiments” unless expressly specified otherwise. The terms “including,” “comprising,” “having,” and variations thereof mean “including but not limited to” unless expressly specified otherwise. An enumerated listing of items does not imply that any or all of the items are mutually exclusive and/or mutually inclusive, unless expressly specified otherwise. The terms “a,” “an,” and “the” also refer to “one or more” unless expressly specified otherwise. The term “and/or” indicates embodiments of one or more of the listed elements, with “A and/or B” indicating embodiments of element A alone, element B alone, or elements A and B taken together. 
     Furthermore, the described features, advantages, and characteristics of the embodiments may be combined in any suitable manner. One skilled in the relevant art will recognize that the embodiments may be practiced without one or more of the specific features or advantages of a particular embodiment. In other instances, additional features and advantages may be recognized in certain embodiments that may not be present in all embodiments. 
     These features and advantages of the embodiments will become more fully apparent from the following description and appended claims or may be learned by the practice of embodiments as set forth hereinafter. As will be appreciated by one skilled in the art, aspects of the present invention may be embodied as a system, method, and/or computer program product. Accordingly, aspects of the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment (including firmware, resident software, micro-code, etc.) or an embodiment combining software and hardware aspects that may all generally be referred to herein as a “circuit,” “module,” or “system.” Furthermore, aspects of the present invention may take the form of a computer program product embodied in one or more computer readable medium(s) having program code embodied thereon. 
     Many of the functional units described in this specification have been labeled as modules, in order to more particularly emphasize their implementation independence. For example, a module may be implemented as a hardware circuit comprising custom VLSI circuits or gate arrays, off-the-shelf semiconductors such as logic chips, transistors, or other discrete components. A module may also be implemented in programmable hardware devices such as field programmable gate arrays, programmable array logic, programmable logic devices or the like. 
     Modules may also be implemented in software for execution by various types of processors. An identified module of program code may, for instance, comprise one or more physical or logical blocks of computer instructions which may, for instance, be organized as an object, procedure, or function. Nevertheless, the executables of an identified module need not be physically located together but may comprise disparate instructions stored in different locations which, when joined logically together, comprise the module and achieve the stated purpose for the module. 
     Indeed, a module of program code may be a single instruction, or many instructions, and may even be distributed over several different code segments, among different programs, and across several memory devices. Similarly, operational data may be identified and illustrated herein within modules and may be embodied in any suitable form and organized within any suitable type of data structure. The operational data may be collected as a single data set or may be distributed over different locations including over different storage devices, and may exist, at least partially, merely as electronic signals on a system or network. Where a module or portions of a module are implemented in software, the program code may be stored and/or propagated on in one or more computer readable medium(s). 
     The computer readable medium may be a tangible computer readable storage medium storing the program code. The computer readable storage medium may be, for example, but not limited to, an electronic, magnetic, optical, electromagnetic, infrared, holographic, micromechanical, or semiconductor system, apparatus, or device, or any suitable combination of the foregoing. 
     More specific examples of the computer readable storage medium may include but are not limited to a portable computer diskette, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or Flash memory), a portable compact disc read-only memory (CD-ROM), a digital versatile disc (DVD), an optical storage device, a magnetic storage device, a holographic storage medium, a micromechanical storage device, or any suitable combination of the foregoing. In the context of this document, a computer readable storage medium may be any tangible medium that can contain, and/or store program code for use by and/or in connection with an instruction execution system, apparatus, or device. 
     The computer readable medium may also be a computer readable signal medium. A computer readable signal medium may include a propagated data signal with program code embodied therein, for example, in baseband or as part of a carrier wave. Such a propagated signal may take any of a variety of forms, including, but not limited to, electrical, electro-magnetic, magnetic, optical, or any suitable combination thereof. A computer readable signal medium may be any computer readable medium that is not a computer readable storage medium and that can communicate, propagate, or transport program code for use by or in connection with an instruction execution system, apparatus, or device. Program code embodied on a computer readable signal medium may be transmitted using any appropriate medium, including but not limited to wireline, optical fiber, Radio Frequency (RF), or the like, or any suitable combination of the foregoing 
     In one embodiment, the computer readable medium may comprise a combination of one or more computer readable storage mediums and one or more computer readable signal mediums. For example, program code may be both propagated as an electro-magnetic signal through a fiber optic cable for execution by a processor and stored on RAM storage device for execution by the processor. 
     Program code for carrying out operations for aspects of the present invention may be written in any combination of one or more programming languages, including an object-oriented programming language such as Python, Ruby, R, Java, Java Script, Smalltalk, C++, C sharp, Lisp, Clojure, PHP or the like and conventional procedural programming languages, such as the “C” programming language or similar programming languages. The program code may execute entirely on the user&#39;s computer, partly on the user&#39;s computer, as a stand-alone software package, partly on the user&#39;s computer and partly on a remote computer or entirely on the remote computer or server. In the latter scenario, the remote computer may be connected to the user&#39;s computer through any type of network, including a local area network (LAN) or a wide area network (WAN), or the connection may be made to an external computer (for example, through the Internet using an Internet Service Provider). The computer program product may be shared, simultaneously serving multiple customers in a flexible, automated fashion. 
     The computer program product may be integrated into a client, server and network environment by providing for the computer program product to coexist with applications, operating systems and network operating systems software and then installing the computer program product on the clients and servers in the environment where the computer program product will function. In one embodiment software is identified on the clients and servers including the network operating system where the computer program product will be deployed that are required by the computer program product or that work in conjunction with the computer program product. This includes the network operating system that is software that enhances a basic operating system by adding networking features. 
     Furthermore, the described features, structures, or characteristics of the embodiments may be combined in any suitable manner. In the following description, numerous specific details are provided, such as examples of programming, software modules, user selections, network transactions, database queries, database structures, hardware modules, hardware circuits, hardware chips, etc., to provide a thorough understanding of embodiments. One skilled in the relevant art will recognize, however, that embodiments may be practiced without one or more of the specific details, or with other methods, components, materials, and so forth. In other instances, well-known structures, materials, or operations are not shown or described in detail to avoid obscuring aspects of an embodiment. 
     The embodiments may transmit data between electronic devices. The embodiments may further convert the data from a first format to a second format, including converting the data from a non-standard format to a standard format and/or converting the data from the standard format to a non-standard format. The embodiments may modify, update, and/or process the data. The embodiments may store the received, converted, modified, updated, and/or processed data. The embodiments may provide remote access to the data including the updated data. The embodiments may make the data and/or updated data available in real time. The embodiments may generate and transmit a message based on the data and/or updated data in real time. 
     Aspects of the embodiments are described below with reference to schematic flowchart diagrams and/or schematic block diagrams of methods, apparatuses, systems, and computer program products according to embodiments of the invention. It will be understood that each block of the schematic flowchart diagrams and/or schematic block diagrams, and combinations of blocks in the schematic flowchart diagrams and/or schematic block diagrams, can be implemented by program code. The program code may be provided to a processor of a general-purpose computer, special purpose computer, sequencer, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions/acts specified in the schematic flowchart diagrams and/or schematic block diagrams block or blocks. 
     The program code may also be stored in a computer readable medium that can direct a computer, other programmable data processing apparatus, or other devices to function in a particular manner, such that the instructions stored in the computer readable medium produce an article of manufacture including instructions which implement the function/act specified in the schematic flowchart diagrams and/or schematic block diagrams block or blocks. 
     The program code may also be loaded onto a computer, other programmable data processing apparatus, or other devices to cause a series of operational steps to be performed on the computer, other programmable apparatus or other devices to produce a computer implemented process such that the program code which executed on the computer or other programmable apparatus provide processes for implementing the functions/acts specified in the flowchart and/or block diagram block or blocks. 
     The schematic flowchart diagrams and/or schematic block diagrams in the Figures illustrate the architecture, functionality, and operation of possible implementations of apparatuses, systems, methods and computer program products according to various embodiments of the present invention. In this regard, each block in the schematic flowchart diagrams and/or schematic block diagrams may represent a module, segment, or portion of code, which comprises one or more executable instructions of the program code for implementing the specified logical function(s). 
     It should also be noted that, in some alternative implementations, the functions noted in the block may occur out of the order noted in the Figures. For example, two blocks shown in succession may, in fact, be executed substantially concurrently, or the blocks may sometimes be executed in the reverse order, depending upon the functionality involved. Other steps and methods may be conceived that are equivalent in function, logic, or effect to one or more blocks, or portions thereof, of the illustrated Figures. 
     Although various arrow types and line types may be employed in the flowchart and/or block diagrams, they are understood not to limit the scope of the corresponding embodiments. Indeed, some arrows or other connectors may be used to indicate only the logical flow of the depicted embodiment. For instance, an arrow may indicate a waiting or monitoring period of unspecified duration between enumerated steps of the depicted embodiment. It will also be noted that each block of the block diagrams and/or flowchart diagrams, and combinations of blocks in the block diagrams and/or flowchart diagrams, can be implemented by special purpose hardware-based systems that perform the specified functions or acts, or combinations of special purpose hardware and program code. 
     The description of elements in each figure may refer to elements of proceeding figures. Like numbers refer to like elements in all figures, including alternate embodiments of like elements. 
       FIG.  1 A  is a schematic block diagram of an access control system  100 . The system  100  includes at least one section  109 . Each section  109  includes at least one equipment unit  111 . An equipment unit  111  may control and/or provide power to automation and/or electrical equipment such as a motor controller starter, a variable frequency drive, an electrical motor, a transformer, lights, etc. In one embodiment, the equipment unit  111  is a Motor Control Center (MCC) unit. A section  109  may also include a wire way  113 . The wire way  113  may route and provide access to wiring from the equipment units  111 . 
     Because the equipment units  111  may manage high electrical currents and/or control automation equipment, it is vital that access to the equipment units  111  be restricted to only qualified, authorized users especially if equipment units  111  are energized and, therefore, exposing the user to electrical shock and/or arc flash risk. Unfortunately, the number of potential users in a factory setting is often very large, complicating the management of access to the equipment units  111 . The embodiments described herein authenticate the user of an equipment unit  111  with a user credential and determine whether the user is authorized to access the equipment unit  111  with an equipment authorization. Only if the user is authenticated and authorized to access the equipment unit  111  will the embodiments provide access to the equipment unit  111  as will be described hereafter. As a result, access to the equipment units  111  is efficiently and safely managed. The embodiments do not interfere with electrical safety procedures for equipment units  111  such as Lock-Out/Tag-Out. 
       FIG.  1 B  is a schematic block diagram of an access control system  100 . The sections  109  of  FIG.  1 A  are shown. In addition, the system  100  includes at least one engineering workstation  105 , a programmable logic controller (PLC)  131 , a server  117 , and/or a network  115 . The network  115  may be a local area network, a wide area network, the Internet, a Wi-Fi network, or combinations thereof. 
     The engineering workstations  105  and/or PLC  131  may communicate with the sections  109  via a secure conduit  103 . The secure conduit  103  may provide Ethernet/IP CIP security. In one embodiment, the secure conduit  103  protects against unauthorized electronic access to the automation devices located in the sections  109 . In a certain embodiment, the secure conduit  103  provides protection against unintentional access to the automation devices located in the sections  109 . 
     The engineering workstations  105 , PLC  131 , and/or server  117  may manage the equipment units  111 . The server  117  may be a FACTORYTALK® server  117 . In addition, the engineering workstations  105 , the PLC  131 , and/or the server  117  may manage access to the equipment units  111  of the sections  109 . In one embodiment, the engineering workstations  105 , the PLC  131 , and/or the server  117  may release a unit lock for an equipment unit  111  with the unit lock credential and/or a user credential as will be described hereafter. 
       FIG.  1 C  is a schematic block diagram of an access control system  100 . The system  100  of  FIG.  1 B  is shown with the sections  109  disposed in an access-controlled room  107 . For example, the access-controlled room  107  may only be accessed via locked doors. The locked doors may be opened with the unit lock credential and/or the user credential. 
       FIG.  1 D  is a schematic block diagram of an access control system  100 . The system  100  of  FIG.  1 B  is shown with lock controllers in each section  109 . The lock controllers  112  may control and/or manage unit locks. For example, the lock controllers  112  may release and/or set the unit locks as will be described hereafter. In one embodiment, the lock controllers  112  are GUARDLINK™ compatible. 
       FIG.  2 A  is a perspective drawing of an equipment unit  111 . In the depicted embodiment, the equipment unit  111  includes two unit locks  125 . A unit lock  125  may receive power when the equipment unit  111  is disconnected from power. In one embodiment, the unit lock  125  receives power that does not exceed 24 Volts Direct Current (DC). The unit locks  125  may prevent an equipment unit door  121  of the equipment unit  111  from being opened. A manual unit lock  125   a  is shown that employs a padlock to us secure the equipment unit door  121 . The manual unit lock  125   a  is further described in  FIG.  2 E . 
     A safety lock unit lock  125   b  is also shown. The safety lock unit lock  125   b  may prevent the equipment unit door  121  from being opened unless the safety lock unit lock  125   b  receives a command and/or credential such as from the engineering workstations  105 , the PLC  131 , and/or the server  117  via the secure conduit  103 . The safety lock unit lock  125   b  may receive a command and/or credential from a local lock controller installed in each equipment unit  111  and/or in a section  109 . 
       FIG.  2 B  is a perspective drawing of an equipment unit  111 . The manual unit lock  125   a  and the safety lock unit lock  125   b  are shown. 
       FIG.  2 C  is a perspective drawing of a section  109 . A plurality of equipment units  111  are disposed in the section  109 . In the depicted embodiment, the equipment units  111  are adjacent to the wire way  113 . The wire way  113  routes wires for the equipment units  111 . In addition, the wire way  113  provides access to the wires. The wire way  113  includes a wire way door  123  that provides access to the wires. 
     An expansion plate  119  is secured to the section  109  and blocks the equipment unit door  121  from opening. The expansion plate  119  may only be removed if the wire way door  123  is open. In one embodiment, a unit lock  125  such as the safety lock unit lock  125   b  secures the wire way door  123 . As a result, the unit lock  125  of the wire way door  123  is used to secure a plurality of equipment unit doors  121 . The unit lock  125  is released from the wire way door  113  to release the expansion plate  119  and release the equipment unit doors  121 . 
       FIG.  2 D  is a close-up perspective drawing of the equipment unit  111  and the wire way  113  of  FIG.  2 C . in the depicted embodiment, the expansion plate  119  is secured by a pin  128 . The pin  128  may only be removed after opening the wire way door  123  in response to releasing the unit lock  125  on the wire way  113 . 
       FIG.  2 E  is perspective drawings of the manual unit lock  125   a , a padlock  137 , and a key  133 . The manual unit lock  125   a  includes a release pin  127 . The release pin  127  secures an equipment unit door  121  or a wire way door  123 . The release pin  127  must be turned and/or extended outward to release the manual unit lock  125   a  and open the equipment unit door  121  or the wire way door  123 . However, if the padlock  137  is threaded through lock holes  129  on the manual unit lock  125   a , the release pin  127  cannot be turned and/or extend outward. As a result, the padlock  137  prevents opening the equipment unit door  121  or the wire way door  123  and accessing the equipment unit  111  unless the padlock  137  is opened with the key  133  and removed from the lock holes  129 . 
       FIG.  2 F  is a perspective drawing of a safety lock unit lock  125   b . The safety lock unit lock  125   b  includes an actuator  141  that secures a stop  139 . The stop  139  is connected to an equipment unit door  121  or a wire way door  123 . The stop  139  prevents the equipment unit door  121  or the wire way door  123  from opening. If the actuator  141  is activated in response to a command, the actuator  141  releases the stop  139  and allows the equipment unit door  121  to open. In one embodiment, the unit lock  125   b  is GUARDLINK™ compatible 
       FIG.  2 G  is a perspective drawing of an RFID  135 . The RFID  135  may store a user credential. The RFID  135  may communicate the user credential when interrogated by a tag reader. The RFID  135  may be used to authenticate a user as will be described hereafter. 
       FIG.  2 H  is a drawing of an electronic device  136 . In the depicted embodiment, the electronic device  136  is a mobile telephone. The electronic device  136  may also be a tablet computer, a laptop computer, and the like. The electronic device  136  may communicate the user credential to a unit lock  125  and/or lock controller  112 . In one embodiment, the electronic device  136  executes an application that communicates with the unit  125  and/or lock controller  112 . 
       FIG.  3 A  is a schematic block diagram of access data  300 . The access data  300  may be employed to authenticate the user of an equipment unit  111  and/or to determine whether the user is authorized to access the equipment unit  111 . The access data  300  may be organized as a data structure in a memory. In the depicted embodiment, the access data  300  includes a plurality of equipment records  301  and a plurality of user records  303 . In one embodiment, each equipment unit  111  and/or wire way  113  has an equipment record  301 . In a certain embodiment, each type of equipment unit  111  has an equipment record  301 . The equipment record  301  is described hereafter in  FIG.  3 B . 
     Each user may have a user record  303 . In a certain embodiment, each category of user has a user record  303 . The user record  303  is described hereafter in  FIG.  3 C . 
       FIG.  3 B  is a schematic block diagram of the equipment record  301 . The equipment record  301  may be employed to manage access to an equipment unit  111  or to a type of equipment unit  111 . The equipment record  301  may be organized as a data structure in a memory. In the depicted embodiment, the equipment record  301  includes a unit identifier  337 , an equipment status  331 , the unit lock credential  333 , and/or a plurality of user access records  335 . 
     The unit identifier  337  may identify the equipment unit  111 . In one embodiment, the unit identifier  337  identifies the type of equipment unit  111 . For example, all MCC units may share a unit identifier  337 . 
     The equipment status  331  may record a status of the equipment unit  111 . The equipment status  331  may be one of energized and un-energized. In addition, the equipment status  331  maybe one of locked and unlocked. 
     The unit lock credential  333  may be employed to release the unit lock  125  that secures the equipment unit  111 . In a certain embodiment, the unit lock credential  333  is communicated to the safety lock unit lock  125   b , causing the actuator  141  to release the stop  139 . In addition, the unit lock credential  333  may provide access to the electronic and/or physical key  133 , allowing a user to release the padlock  137  of the manual unit lock  125   a.    
     A user access record  335  may record each access of a user to the equipment unit  111 . The user access record  335  may record the user credential, a username, and/or a timestamp. 
       FIG.  3 C  is a schematic block diagram of the user record  303 . The user record  303  may be employed to manage the access of a user to a plurality of equipment units  111 . The user record  303  may be organized as a data structure in a memory. In the depicted embodiment, the user record  303  includes the user credential  351  and equipment authorizations  353 . 
     The user credential  351  maybe an alphanumeric string. The alphanumeric string may be encoded on and transmitted by the RFID  135 . The alphanumeric string user credential  351  may be captured by the system  100  when the RFID  135  is read by a tag reader. 
     In one embodiment, the user credential  351  comprises a username and a password. The user credential  351  may be captured by the system  100  when entered into the engineering workstation  105  and/or the PLC  131 . In addition, the user credential  351  may include a biometric for the user. For example, the user credential  351  may include a fingerprint, a voiceprint, and/or retinal scan. 
     The equipment authorizations  353  are described in  FIG.  3 D . the equipment authorizations  353  may be in a standard format. 
       FIG.  3 D  is a schematic block diagram of the equipment authorizations  353 . In the depicted embodiment, the equipment authorizations  353  include entries for a plurality of equipment units  111 . The entry for each equipment unit  111  is indexed by the unit identifier  337 . 
     The user authorization  355  for each unit identifier  337  indicates whether the user and/or a category of user may access the corresponding equipment unit  111  and/or type of equipment unit  111 . For example, the user authorization  355  may indicate that the user may access the equipment unit  111  or not access the equipment unit  111 . In addition, the user authorization  355  may indicate the circumstances under which the user may access the corresponding equipment unit  111 . For example, the user may be authorized to access the equipment unit  111  when the equipment unit  111  is energized. Alternatively, the user may be authorized to access the equipment unit  111  only when the equipment unit  111  is not energized. 
     In one embodiment, each entry includes the unit lock credential  333  for the corresponding equipment unit  111 . The unit lock credential  333  may be unique to the user. Alternatively, the unit lock credential  333  may be common to all users and/or categories of users. 
       FIG.  4 A  is a schematic block diagram of a computer  400 . The computer  400  may be embodied in an engineering workstation  105 , the PLC  131 , electronic device  136 , lock controller  112 , and/or the server  117 . In the depicted embodiment, the computer  400  includes a processor  405 , a memory  410 , and communication hardware  415 . The memory  410  may include a semiconductor storage device, a hard disk drive, an optical storage device, a micromechanical storage device, or combinations thereof. The memory  410  may store code. The processor  405  may execute the code. The communication hardware  415  may communicate with other devices and/or communication channels such as the network  115  and/or the secure conduit  103 . 
       FIG.  4 B  is a schematic block diagram of the tag reader  420 . The tag reader  420  may be disposed on an equipment unit  111 , a section  109 , an access-controlled room  107 , an engineering workstation  105 , a PLC  131 , and/or a server  117 . The tag reader  420  may capture the user credential  351  from an RFID  135 . The user credential  351  may be captured to authenticate the user. The tag reader  420  may receive the RFID  135  comprising the user credential  351  to authenticate the user and/or to determine whether the user is authorized to access the equipment unit  111  as will be described hereafter. 
       FIG.  5 A  is a schematic flow chart diagram of a secure access method  500 . The method  500  may manage the access of the user to an equipment unit  111 , a wire way  113 , a section  109 , and/or an access-controlled room  107 . The method  500  may be performed by the system  100 . In addition, the method  500  may be performed by the processor  405  of the computer  400 . 
     The method  500  starts, and in one embodiment, the processor  405  authenticates  501  a user of an equipment unit  111 . The user may be authenticated  501  with the user credential  351  for the user. The user may present an RFID  135  to a tag reader  420 . The tag reader  420  may capture the user credential  351  from the RFID  135 . The tag reader  420  may further communicate the user credential  351  to the engineering workstation  105 , the PLC  131 , and/or the server  117 . The user may be authenticated  501  based on receipt of the user credential  351 . 
     In one embodiment, the user is authenticated  501  from the engineering workstation  105 . The user may be authenticated  501  by entering a username and password of the user credential  351  at the engineering workstation  105 . The engineering workstation  105 , the PLC  131 , and/or the server  117  may receive the username and the password and authenticate  501  the user in response to authenticating the username and the password. 
     In a certain embodiment, the user is authenticated  501  by receiving a biometric for the user. For example, the tag reader  420 , PLC  131 , and/or the engineering workstation  105  may capture the biometric from the user and compare the captured biometric with the biometric of the user credential  351 . The user may be authenticated  501  if the captured biometric and the biometric from the user credential  351  match. 
     The processor  405  may further determine  503  the equipment status  331 . In one embodiment, the processor  405  queries the equipment unit  111  for the equipment status  331 . In addition, the processor  405  may query the server  117  or the PLC  131  for the equipment status  331 . 
     The processor  405  may determine  505  whether the user is authorized to access the equipment unit  111 . In addition, the processor  405  may determine  505  whether the user is authorized and/or authenticated to access the equipment unit  111 , wire way  113 , and/or access-controlled room  107 . The determination that the user is authorized may be based on the equipment status  331 . In one embodiment, the processor  405  only determines whether the user is authorized and/or authenticated in response to authenticating  501  the user. The processor  405  may determine  505  the user is authorized to access the equipment unit  111  with the equipment authorization  353 . In addition, the processor  405  may determine  505  whether the user is authorized to access the equipment unit  111  based on the user authorization  355 . Table 1 illustrates one embodiment of determining whether the user is authorized to access the equipment unit  111 , wire way  113 , and/or access-controlled room  107 . 
     
       
         
           
               
               
               
               
             
               
                 TABLE 1 
               
               
                   
               
               
                 User 
                 Equipment 
                 User 
                   
               
               
                 Authentication 
                 Status 331 
                 Authorization 355 
                 Authorized? 
               
               
                   
               
             
            
               
                 No 
                 Unenergized 
                 Unenergized 
                 No 
               
               
                   
                   
                 Access 
                   
               
               
                 No 
                 Unenergized 
                 Energized 
                 No 
               
               
                   
                   
                 Access 
                   
               
               
                 No 
                 Energized 
                 Unenergized 
                 No 
               
               
                   
                   
                 Access 
                   
               
               
                 No 
                 Energized 
                 Energized 
                 No 
               
               
                   
                   
                 Access 
                   
               
               
                 Yes 
                 Unenergized 
                 Unenergized 
                 Yes 
               
               
                   
                   
                 Access 
                   
               
               
                 Yes 
                 Unenergized 
                 Energized 
                 Yes 
               
               
                   
                   
                 Access 
                   
               
               
                 Yes 
                 Energized 
                 Unenergized 
                 No 
               
               
                   
                   
                 Access 
                   
               
               
                 Yes 
                 Energized 
                 Energized 
                 Yes 
               
               
                   
                   
                 Access 
               
               
                   
               
            
           
         
       
     
     In one embodiment, specific equipment unit functions may require a specific equipment authorization  353 . The equipment unit functions may include locking an equipment unit  111 , unlocking a de-energized equipment unit  111 , unlocking an energized equipment unit  111 , locking a wire way  113 , unlocking a wire way  113  with energized equipment units  111 , and unlocking a wire way  113  with de-energized equipment units  111 . 
     If the user is not authorized and/or authenticated, the processor  405  may log  509  the access attempt and the method  500  ends. If the user is authorized and authenticated to access the equipment unit  111 , the processor  405  may release  507  the unit lock  125  for the equipment unit  111 . The processor  405  may release  507  the unit lock  125  with the unit lock credential  333  and/or the user credential  351 . 
     The processor  405  may communicate the unit lock credential  333  and/or the user credential  351  to the lock controller  112 . The lock controller  112  may release  507  the unit lock  125  for the equipment unit  111 . 
     The processor  405  may communicate the unit lock credential  333  and/or the user credential  351  to the electronic device  136  to release  507  the unit lock  125 . In addition, the electronic device  136  may communicate the unit lock credential  333  and/or the user credential  351  to release  507  the unit lock  125 . For example, an application executing on the electronic device  136  may communicate the unit lock credential  333  and/or the user credential  351  to the lock controller  112  to release the unit lock  125 . 
     In one embodiment, the processor  405  provides and/or communicates the unit lock credential  333  and/or the user credential  351  to provide the user access to a key  133  for a padlock  137  on a manual unit lock  125   a . In a certain embodiment, the key  133  is automatically provided in response to the unit lock credential  333  and/or the user credential  351 . For example, the key  133  may be released from a lockbox. 
     In one embodiment, the processor  405  communicates the unit lock credential  333  and/or the user credential  351  to an administrator that provides the key  133 . For example, the processor  405  may send an email with the unit lock credential  333 , the user credential  351 , and the unit identifier  337  to the administrator. 
     In one embodiment, the processor  405  communicates the unit lock credential  333  to the safety lock unit lock  125   b . The safety lock unit lock  125   b  may release the stop  139  in response to receiving the unit lock credential  333 . 
     The unit lock credential  333  and/or the user credential  351  may provide access to the user to the equipment unit  111 , the wire way  113 , the section  109 , and/or the access controls room  107 . As a result, the user may access the equipment unit  111 . 
     The processor  405  further logs  509  the access to the equipment unit  111  by the user in a user access record  335  and the method  500  ends. In one embodiment, the user credential  351 , the equipment authorizations  353 , the user authorization  355 , the equipment status  331 , and/or a timestamp are recorded to the user access record  335 . 
     The method  500  provides identification and authentication control, preventing unintentional access to the equipment unit  111 , the wire way  113 , section  109 , and/or the access controls room  107 . In one embodiment, the method  500  identifies and authenticates all entities, including human users, software users, and electronic devices  136 . The method  500  may protect against casual and/or coincidental access by unauthenticated entities. As a result, the safety of the system  100  is enhanced. 
       FIG.  5 B  is a schematic flow chart diagram of a unit lock release method  550 . The method  550  releases the unit lock  125 . In one embodiment, the method describes step  507  of  FIG.  5 A . The method  550  may be performed by the system  100 . In addition, the method  550  may be performed by the processor  405  of the computer  400 . 
     The method  550  starts, and in one embodiment, the processor  405  converts  551  the unit lock credential  333 . The unit lock credential  333  may be converted  551  to a standard format. In one embodiment, the standard format is for transmission of the unit lock credential  333 . The standard format may include encryption. In addition, the standard format may include a timestamp. In one embodiment, the standard format includes the user credential  351 . 
     The processor  405  may further transmit  553  the converted unit lock credential  333 . The converted unit lock credential  333  may be transmitted  553  to a unit lock  125  such as the safety lock unit lock  125   b , to a door, to it administrator, and/or to a lockbox, and/or to an automation device inside the unit  111 . 
     The unit lock  125  may be released  555  in response to receiving the converted unit lock credential  333  and the method  550  ends. For example, the safety lock unit lock  125   b  may release  555  in response to receiving the converted unit lock credential  333 . In one embodiment, the unit lock  125  is released  555  in response to wirelessly receiving the unit lock credential  333 . The unit lock credential  333  may be communicated via a BLUETOOTH® communication or the like. The unit lock  125  may be released by providing the user access to the access-controlled room  107 . 
       FIG.  5 C  is a schematic flow chart diagram of a data conversion method  600 . The method  600  may convert the user credential  351  and/or the unit lock credential  333 . The method  600  may be performed by the system  100 . In addition, the method  600  may be performed by the processor  405  of the computer  400 . 
     The method  600  starts, and in one embodiment, the processor  405  receives  601  the user credential  351 . The user may enter the user credential  351  at the engineering workstation  105  and/or PLC  131 . In addition, the tag reader  420  may capture the user credential  351 . For example, the tag reader  420  may read the user credential  351  from the RFID  135  and/or capture a biometric user credential  351  from the user. 
     The processor  405  may convert  603  the user credential  351  to a standard format. The standard format may include a timestamp. In addition, the standard format may include an encrypted verification value. The encrypted verification value may be used to verify the source of the user credential  351 . 
     The processor  405  may further store  605  the user credential  351 . For example, the user credential  351  may be stored in the memory  410 . In one embodiment, the processor  405  transmits  607  the user credential  351 . For example, the user credential  351  may be transmitted  607  to the server  117 . 
     The processor  405  may receive the unit lock credential  333 . In one embodiment, the unit lock credential  333  is received  609  from the server  117 , the engineering workstation  105 , and/or the PLC  131 , in response to the user being authenticated and authorized to access the equipment unit  111 . The processor  405  may convert the unit lock credential  333  to a standard format. The standard format may include a timestamp. In addition, the standard format may include an encrypted verification value. The encrypted verification value may be used to verify the source of the unit lock credential  333 . 
     The processor  405  may store  613  the converted unit lock credential  333 . The unit lock credential  333  may be stored in the memory  410 . The processor  405  may further transmit  615  the unit lock credential  333  and the method  600  ends. For example, the processor  405  may transmit  615  the unit lock credential  333  to the unit lock  125 . 
     The method  600  converts the user credential  351  and/or the unit lock credential  333  to a standard format that supports the authentication and authorization for the user to access the equipment unit  111 . As a result, the efficiency and effectiveness of the computer  400  and/or process  405  in providing secure and safe access control to the equipment units  111  is improved. 
       FIG.  5 D  is a schematic flow chart diagram of a secure access method  650 . The method  650  may manage the access of the user to an equipment unit  111 , a wire way  113 , a section  109 , and/or an access-controlled room  107 . The method  650  may be performed by the system  100 . In addition, the method  650  may be performed by the processor  405  of the computer  400 . 
     The method  650  starts, and in one embodiment, the processor  405  authenticates  651  a user of an equipment unit  111 . The user may be authenticated  651  with the user credential  351  for the user. The user may present an RFID  135  to a tag reader  420 . The tag reader  420  may capture the user credential  351  from the RFID  135 . The tag reader  420  may further communicate the user credential  351  to the engineering workstation  105 , the PLC  131 , and/or the server  117 . The user may be authenticated  651  based on receipt of the user credential  351 . 
     In one embodiment, the user is authenticated  651  from the engineering workstation  105 . The user may be authenticated  651  by entering a username and password of the user credential  351  at the engineering workstation  105 . The engineering workstation  105 , the PLC  131 , and/or the server  117  may receive the username and the password and authenticate  501  the user in response to authenticating the username and the password. 
     In a certain embodiment, the user is authenticated  651  by receiving a biometric for the user. For example, the tag reader  420 , PLC  131 , and/or the engineering workstation  105  may capture the biometric from the user and compare the captured biometric with the biometric of the user credential  351 . The user may be authenticated  501  if the captured biometric and the biometric from the user credential  351  match. 
     The processor  405  may further determine  653  the equipment status  331 . In one embodiment, the processor  405  queries the equipment unit  111  for the equipment status  331 . In addition, the processor  405  may query the server  117  and/or the PLC  131  for the equipment status  331 . 
     The processor  405  may determine  655  whether the user is authorized to access the equipment unit  111  with the equipment authorization  355 . In addition, the processor  405  may determine  655  whether the user is authorized to access the energized equipment unit  111 . The user authorization  355  may indicate that the user is authorized to access the equipment unit  111  when the equipment unit  111  is energized. Alternatively, the user authorization  355  may indicate that the user is not authorized to access the equipment unit  111  when the equipment unit  111  is energized. 
     If the user is not authorized to access the energized equipment unit  111 , the processor  405  may determine  657  whether the equipment unit  111  is powered down. If the equipment unit  111  is not powered down, the processor  405  may log  663  the access to the equipment unit  111  by the user in a user access record  335  and the method  650  ends. In one embodiment, the user credential  351 , the equipment authorizations  353 , the user authorization  355 , the equipment status  331 , and/or a timestamp are recorded to the user access record  335 . 
     If the user is not authorized to access the energized equipment unit  111  and the equipment unit  111  is not energized or if the user is authorized to access the energized equipment unit  111 , the processor  405  may authenticate  659  the unit lock credential  333 . Specific equipment unit functions may require a specific unit lock credential  333 . The equipment unit functions may include locking an equipment unit  111 , unlocking a de-energized equipment unit  111 , unlocking an energized equipment unit  111 , locking a wire way  113 , unlocking a wire way  113  with energized equipment units  111 , and unlocking a wire way  113  with de-energized equipment units  111 . The unit lock credential  333  may only be authenticated  659  in response to the user being authenticated. 
     If the unit lock credential  333  is not authenticated, the processor  405  may log  663  the access attempt and the method  650  ends. If the unit lock credential  333  is authenticated, the processor  405  may release  661  the unit lock  125  for the equipment unit  111 . The processor  405  may release  661  the unit lock  125  with the unit lock credential  333  and/or the user credential  351 . The processor  405  may communicate the unit lock credential  333  and/or the user credential  351  to the lock controller  112 . The lock controller  112  may release  661  the unit lock  125  for the equipment unit  111 . 
     In one embodiment, in response to the unit lock credential  333  being authenticated and the user being authenticated and authorized to access the equipment unit  111  energized or the unit lock credential being authenticated  333  and the user being authorized to access the equipment unit  111  un-energized and the equipment unit  111  being un-energized, the unit lock  125  for the equipment unit  111  may be released  661  with the unit lock credential  333  and the user credential  351 . 
     The processor  405  may communicate the unit lock credential  333  and/or the user credential  351  to the electronic device  136  to release  661  the unit lock  125 . In addition, the electronic device  136  may communicate the unit lock credential  333  and/or the user credential  351  to release  661  the unit lock  125 . For example, an application executing on the electronic device  136  may communicate the unit lock credential  333  and/or the user credential  351  to the lock controller  112  to release  661  the unit lock  125 . 
     In one embodiment, the processor  405  provides and/or communicates the unit lock credential  333  and/or the user credential  351  to provide the user access to a key  133  for a padlock  137  on a manual unit lock  125   a . In a certain embodiment, the key  133  is automatically provided in response to the unit lock credential  333  and/or the user credential  351 . For example, the key  133  may be released from a lockbox. 
     In one embodiment, the processor  405  communicates the unit lock credential  333  and/or the user credential  351  to an administrator that provides the key  133 . For example, the processor  405  may send an email with the unit lock credential  333 , the user credential  351 , and the unit identifier  337  to the administrator. 
     In one embodiment, the processor  405  communicates the unit lock credential  333  to the safety lock unit lock  125   b . The safety lock unit lock  125   b  may release  661  the stop  139  in response to receiving the unit lock credential  333 . The unit lock credential  333  and/or the user credential  351  may provide access to the user to the equipment unit  111 , the wire way  113 , the section  109 , and/or the access controls room  107 . As a result, the user may access the equipment unit  111 . 
     The processor  405  may further log  663  the access to the equipment unit  111  by the user in a user access record  335  and the method  650  ends. In one embodiment, the user credential  351 , the equipment authorizations  353 , the user authorization  355 , the equipment status  331 , and/or a timestamp are recorded to the user access record  335 . 
     The method  650  provides identification and authentication control, preventing unintentional access to the equipment unit  111 , the wire way  113 , section  109 , and/or the access controls room  107  when one or more are energized if the user is not authorized to access the energized equipment unit  111 . In one embodiment, the method  650  provides access to the energized equipment unit  111  if the user is authorized to access the energized equipment unit  111 . The method  650  may protect against casual and/or coincidental access by unauthenticated entities. As a result, the safety of the system  100  is enhanced. 
       FIG.  6 A  is a schematic block diagram of the lock controller  112 . In the depicted embodiment, the lock controller  112  includes an Ethernet connection  621 . The Ethernet connection  621  many communicate the unit lock credential  333  to the lock controller  112 . 
     The Ethernet connection  621  may be a single pair Ethernet connection  621 . The Ethernet connection  621  may include a power voltage  623  and a ground  633 . The power voltage  623  may not exceed 24 Volts Direct Current (DC). The Ethernet connection  621  further includes a receive pair RXN/RXP  625 / 627  and a transmit pair TXN/TXP  629 / 631 . 
     The lock controller  112  may receive power via the power voltage  623  and ground  633 . In one embodiment, the lock controller  112  receives power when the equipment unit  111  and/or lock controller  112  is disconnected from power. The lock controller  112  may receive power that does not exceed 24 Volts DC. 
       FIG.  6 B  is a schematic block diagram of the unit lock  125 . In the depicted embodiment, the unit lock  125  includes the Ethernet connection  621  of  FIG.  6 A . The Ethernet connection  621  many communicate the unit lock credential  333  to the unit lock  125 . 
     The unit lock  125  may receive power via the power voltage  623  and ground  633 . In one embodiment, the unit lock  125  receives power when the equipment unit  111  and/or unit lock  125  is disconnected from power. The unit lock  125  may receive power that does not exceed 24 Volts DC. 
     Problem/Solution 
     Equipment units  111  may manage high electrical currents and/or control automation equipment. If an untrained user accessed the equipment unit  111 , the user could harm himself and/or cause damage to the automation equipment. As a result, only authenticated and authorized users should have access to the equipment unit  111 . 
     The embodiments authenticate a potential user of the equipment unit  111  prior to access by the user. The user may be authenticated with the user credential  351  for the user. As a result, the user is known to the embodiments. The embodiments further determine whether the user is authorized to access the equipment unit  111  with the equipment authorization  353 . By employing both the user credential  351  and the equipment authorization  353 , the security and safety of access to the equipment unit  111  is increased as a user must be both authenticated and authorized. 
     In response to the user being authenticated and authorized, the embodiments release the unit lock  125  for the equipment unit  111  with the unit lock credential  333  or the user credential  351 . Thus, the equipment unit  111  is efficiently and effectively secured from unauthorized access. 
     This description uses examples to disclose the invention and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the invention is defined by the claims and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal language of the claims.