Patent Publication Number: US-9903701-B2

Title: Articulated arm coordinate measurement machine having a rotary switch

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     The Present Application is a Nonprovisional Application of Provisional Application Ser. No. 61/993,077 filed on May 14, 2014, the contents of which are incorporated herein by reference. 
    
    
     BACKGROUND OF THE INVENTION 
     The present disclosure relates to metrology instruments that measure the three-dimensional coordinates of points on an object, and more particularly, to a metrology instrument having near field communications (NFC) capability to communicate with one or more external devices. 
     Metrology instruments, such as portable articulated arm coordinate measuring machines (AACMMs), laser trackers, laser scanners and triangulation scanners for example, have found widespread use in the manufacturing or production of parts where there is a need to rapidly and accurately verify the dimensions of the part during various stages of the manufacturing or production (e.g., machining). Portable metrology instruments represent a vast improvement over known stationary or fixed, cost-intensive and relatively difficult to use measurement installations, particularly in the amount of time it takes to perform dimensional measurements of relatively complex parts. In the instance of a portable AACMM, the user simply guides a probe along the surface of the part or object to be measured. The measurement data are then recorded and provided to the user. In some cases, the data are provided to the user in visual form, for example, three-dimensional (3-D) form on a computer screen. In other cases, the data are provided to the user in numeric form, for example when measuring the diameter of a hole, the text “Diameter=1.0034” is displayed on a computer screen. 
     An example of a prior art portable articulated arm CMM is disclosed in commonly assigned U.S. Pat. No. 5,402,582 (&#39;582), which is incorporated herein by reference in its entirety. The &#39;582 patent discloses a 3-D measuring system comprised of a manually-operated articulated arm CMM having a support base on one end and a measurement probe at the other end. Commonly assigned U.S. Pat. No. 5,611,147 (&#39;147), which is incorporated herein by reference in its entirety, discloses a similar articulated arm CMM. In the &#39;147 patent, the articulated arm CMM includes a number of features including an additional rotational axis at the probe end, thereby providing for an arm with either a two-two-two or a two-two-three axis configuration (the latter case being a seven axis arm). 
     Accordingly, while existing metrology instruments are suitable for their intended purposes the need for improvement remains, particularly in providing a method and apparatus for communicating between the metrology instrument and a device to allow the operator to control a metrology instrument, configure the metrology instrument, or change parameters on the metrology instrument. 
     BRIEF DESCRIPTION OF THE INVENTION 
     In accordance with an embodiment, a rotary switch device is provided. The rotary switch including a housing have an axis of rotation. A first actuator is coupled to the housing. A first switch is coupled to the first actuator, the first actuator being configured to selectively close the first switch. A first electrical circuit is provided. A first antenna circuit is electrically coupled the first switch to the first electrical circuit, wherein the first electrical circuit and first antenna circuit cooperate to modulate an operating field when the first switch is closed. A reader circuit is arranged fixed relative to the axis of rotation, the reader circuit including a transmitter configured to emit the operating field and a receiver configured to detected the modulated operating field. 
     In accordance with another embodiment, a portable articulated arm coordinate measuring machine (AACMM) is provided. The AACMM includes a manually positionable articulated arm having opposed first and second ends, the arm including a plurality of connected arm segments, each of the arm segments including at least one position transducer for producing a position signal. An electronic processing system is electrically coupled to receive the position signals. A probe end is coupled to the first end, the probe end having a housing coupled to the first end to rotate about an axis. A measurement device is coupled to the housing and electrically coupled to the electronic processing system. A first actuator is coupled to the housing. A first switch is coupled to the first actuator, the first actuator being configured to selectively close the first switch. A first electric circuit is provided. A first antenna circuit is electrically coupled to the first switch to the first electric circuit, wherein the first near field communication circuit and first antenna circuit cooperate to modulate an operating field when the first switch is closed. A reader circuit is arranged fixed relative to the axis of rotation, the reader circuit including a transmitter configured to emit the operating field and a receiver configured to detect the modulated operating field. 
     In accordance with another embodiment of the invention, a method of conveying information with a portable articulated arm coordinate measuring machine (AACMM) is provided. The method including the steps of: providing a manually positionable articulated arm portion having opposed first and second ends, the arm portion including a plurality of connected arm segments, each of the arm segments including at least one position transducer for producing a position signal; providing a probe end coupled to the first end, the probe end having a housing arranged to rotate about an axis of rotation, the probe end further having a switch coupled to rotate with the housing, the switching being electrically coupled to a first electric circuit by an antenna circuit, the probe, the probe end further having a reader circuit fixedly arranged relative to the axis of rotation, wherein the electric circuit is arranged to move about the reader circuit; providing a measurement device coupled to the housing; providing an electronic processing system for receiving the position signals from the transducers and for determining a position of the measurement device; emitting an operating field with the reader circuit; closing the switch; modulating the operating field with the electric circuit and antenna circuit in response to the closing of the switch; transmitting a measurement signal to the electronic processing system in response to the reader circuit detecting the modulation of the operating field; and determining the three-dimensional coordinates of the measurement device with the electronic processing system in response to receiving the measurement signal. 
     These and other advantages and features will become more apparent from the following description taken in conjunction with the drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWING 
       The subject matter, which is regarded as the invention, is particularly pointed out and distinctly claimed in the claims at the conclusion of the specification. The foregoing and other features, and advantages of the invention are apparent from the following detailed description taken in conjunction with the accompanying drawings in which: 
         FIG. 1  is a perspective view of a portable articulated arm coordinate measuring machine (AACMM) having embodiments of various aspects of the present invention; 
         FIG. 2  is a perspective view of a laser tracker device having embodiments of various aspects of the present invention; 
         FIG. 3  is a side view of a laser scanner having embodiments of various aspects of the present invention; 
         FIG. 4  is a perspective view of a three-dimensional (3D) triangulation scanner having embodiments of various aspects of the present invention; 
         FIG. 5  is a block diagram of electronics utilized as part of the metrology instruments of  FIGS. 1-4  in accordance with an embodiment; 
         FIG. 6 , including  FIGS. 6A and 6B  taken together, is a block diagram describing detailed features of the electronic data processing system of  FIG. 5  in accordance with an embodiment; 
         FIG. 7  is a block diagram of a near field communication (NFC) tag and NFC reader device; 
         FIG. 8  is a partial schematic perspective view of the AACMM of  FIG. 1  communicating with an external device in accordance with an embodiment of the invention; 
         FIG. 9  is a block diagram of the external device of  FIG. 8  and a portion of the electronic data processing system of  FIG. 7 ; 
         FIG. 10  is a block diagram of the external device of  FIG. 8 ; 
         FIGS. 11-14  are flow diagrams of methods of operating the metrology device of  FIGS. 1-4  and external device of  FIG. 8 ; 
         FIG. 15  is a perspective view illustrating of the AACMM of  FIG. 1  and external device of  FIG. 8  with encoder/bearing cartridges; 
         FIG. 16  is a flow diagram of a method of operating the AACMM of  FIG. 10 ; and 
         FIGS. 17A and 17B  are illustrations of an embodiment of the probe end of the AACMM of  FIG. 1  incorporating a powerless switch. 
     
    
    
     The detailed description explains embodiments of the invention, together with advantages and features, by way of example with reference to the drawings. 
     DETAILED DESCRIPTION OF THE INVENTION 
     An embodiment of the present invention provides communicating between a 3D metrology instrument and a portable device, such as a phone, a tablet or another metrology instrument. Embodiments of the invention provide advantages in facilitating the configuration of settings, such as wireless communications parameters, in the metrology device. Embodiments of the invention provide advantages in allowing the remote control of the metrology device with a portable device. Embodiments of the invention provide still further advantages in allowing the wireless updating of boot load code for the metrology device by an operator. Further embodiments of the invention provide advantages in assignment of identification codes in position transducers through a near field communications circuit. Still further embodiments of the invention provide advantages in allowing service personnel to quickly determine configuration information of the metrology instrument. In still further embodiments of the invention advantages are gained in providing a near field communications device that functions as a powerless switch to eliminate mechanical components such as slip rings. 
       FIGS. 1-4  illustrate exemplary metrology instruments, including an articulated arm coordinate measurement (AACMM) device  100 , a laser tracker device  200 , a time-of-flight (TOF) laser scanner device  300  and a triangulation scanning device  400  (collectively referred to herein as metrology devices) for example, according to various embodiments of the present invention. It should be appreciated that while embodiments herein may refer to specific metrology devices, the claimed invention should not be so limited. In other embodiments, the various embodiments may be used in other metrology devices, such as but not limited to laser line probes, total stations and theodolites for example. 
     Referring now to  FIG. 1 , an AACMM  100  according to various embodiments of the present invention, an articulated arm being one type of coordinate measuring machine. The AACMM  100  may be the same as that described in commonly owned U.S. Pat. No. 8,533,967 entitled “Coordinate Measurement Machine,” the contents of which are incorporated herein by reference. The exemplary AACMM  100  may comprise a six or seven axis articulated measurement device having a probe end  401  that includes a measurement probe housing  102  coupled to an arm portion  104  of the AACMM  100  at one end. 
     The arm portion  104  comprises a first arm segment  106  coupled to a second arm segment  108  by a rotational connection having a first grouping of bearing cartridges  110  (e.g., two bearing cartridges). A second grouping of bearing cartridges  112  (e.g., two bearing cartridges) couples the second arm segment  108  to the measurement probe housing  102 . A third grouping of bearing cartridges  114  (e.g., three bearing cartridges) couples the first arm segment  106  to a base  116  located at the other end of the arm portion  104  of the AACMM  100 . Each grouping of bearing cartridges  110 ,  112 ,  114  provides for multiple axes of articulated movement. Also, the probe end  401  may include a measurement probe housing  102  that comprises the shaft of the seventh axis portion of the AACMM  100  (e.g., a cartridge containing an encoder system that determines movement of the measurement device, for example a contact probe  118 , in the seventh axis of the AACMM  100 ). In this embodiment, the probe end  401  may rotate about an axis extending through the center of measurement probe housing  102 . In use the base  116  is typically affixed to a work surface. 
     Each bearing cartridge within each bearing cartridge grouping  110 ,  112 ,  114  typically contains an encoder system (e.g., an optical angular encoder system). The encoder system (i.e., transducer) provides an indication of the position of the respective arm segments  106 ,  108  and corresponding bearing cartridge groupings  110 ,  112 ,  114  that all together provide an indication of the position of the probe  118  with respect to the base  116  (and, thus, the position of the object being measured by the AACMM  100  in a certain frame of reference—for example a local or global frame of reference). 
     The probe  118  is detachably mounted to the measurement probe housing  102 , which is connected to bearing cartridge grouping  112 . A handle accessory  126  may be removable with respect to the measurement probe housing  102  by way of, for example, a quick-connect interface. In exemplary embodiments, the probe housing  102  houses a removable probe  118 , which is a contacting measurement device and may have different tips  118  that physically contact the object to be measured, including, but not limited to: ball, touch-sensitive, curved and extension type probes. In other embodiments, the measurement is performed, for example, by a non-contacting device such as a laser line probe (LLP). In an embodiment, the handle  126  is replaced with the LLP using the quick-connect interface. Other types of accessory devices may replace the removable handle  126  to provide additional functionality. Examples of such accessory devices include, but are not limited to, one or more illumination lights, a temperature sensor, a thermal scanner, a bar code scanner, a projector, a paint sprayer, a camera, a video camera, an audio recording system or the like, for example. 
     In accordance with an embodiment, the base  116  of the portable AACMM  100  contains or houses an electronic data processing system that includes a base processing system that processes the data from the various encoder systems within the AACMM  100  as well as data representing other arm parameters to support three-dimensional (3-D) positional calculations, and resident application software that allows for relatively complete metrology functions to be implemented within the AACMM  100 . 
     As will be discussed in more detail below, the electronic data processing system  500  in the base  116  may communicate with the encoder systems, sensors, and other peripheral hardware located away from the base  116  (e.g., a LLP that can be mounted to or within the removable handle  126  on the AACMM  100 ). The electronics that support these peripheral hardware devices or features may be located in each of the bearing cartridge groupings  110 ,  112 ,  114  located within the portable AACMM  100 . As will be discussed in more detail herein, each of the angular encoders within the bearing cartridge groupings  110 ,  112 ,  114  includes a definable identification number that allows the electronic data processing system to determine which angular encoder transmitted a positional signal and also compensate for known calibration errors in the particular encoder. The 3-D positional calculations may be determined at least in part on positional signal that includes the angular encoder identification number. 
     An exemplary laser tracker system  200  illustrated in  FIG. 2  includes a laser tracker  202 , a retroreflector target  204 , an electronic data processing system  500 , and an optional auxiliary computer  208 . The laser tracker  200  may be similar to that described in commonly owned U.S. Provisional Application Ser. No. 61/842,572 filed on Jul. 3, 2013, the contents of which are incorporated herein by reference. It should be appreciated that while the electronic data processing system is illustrated external to the laser tracker  200 , this is for exemplary purposes and the electronic data processing system  500  may be arranged within the housing of the laser tracker  200 . An exemplary gimbaled beam-steering mechanism  210  of laser tracker  200  comprises a zenith carriage  212  mounted on an azimuth base  214  and rotated about an azimuth axis  216 . A payload  218  is mounted on the zenith carriage  212  and rotated about a zenith axis  220 . Zenith axis  220  and azimuth axis  216  intersect orthogonally, internally to tracker  200 , at gimbal point  222 , which is typically the origin for distance measurements. 
     A laser beam  224  virtually passes through the gimbal point  222  and is pointed orthogonal to zenith axis  220 . In other words, laser beam  224  lies in a plane approximately perpendicular to the zenith axis  220  and that passes through the azimuth axis  216 . Outgoing laser beam  224  is pointed in the desired direction by rotation of payload  218  about zenith axis  220  and by rotation of zenith carriage  212  about azimuth axis  216 . A zenith angular encoder  226 , internal to the tracker  220 , is attached to a zenith mechanical axis aligned to the zenith axis  220 . An azimuth angular encoder  228 , internal to the tracker, is attached to an azimuth mechanical axis aligned to the azimuth axis  216 . The zenith and azimuth angular encoders  226 ,  228  measure the zenith and azimuth angles of rotation to relatively high accuracy. Outgoing laser beam  224  travels to the retroreflector target  204 , which might be, for example, a spherically mounted retroreflector (SMR). 
     By measuring the radial distance between gimbal point  222  and retroreflector  204 , the rotation angle about the zenith axis  220 , and the rotation angle about the azimuth axis  216 , the position of retroreflector  204  and thus the three-dimensional coordinates of the object being inspected is found by the electronic data processing system  500  within the local spherical coordinate system of the tracker. 
     Referring now to  FIG. 3 , an exemplary laser scanner  300  is shown in accordance with embodiment of the invention. The laser scanner  300  has a measuring head  302  and a base  304 . The laser scanner  300  may be similar to that described in commonly owned United States Patent Publication 2014/0078519 entitled “Laser Scanner,” the contents of which are incorporated by reference herein. The measuring head  302  is mounted on the base  304  such that the laser scanner  300  may be rotated about a vertical axis  306 . In one embodiment, the measuring head  302  includes a gimbal point  308  that is a center of rotation about a vertical axis  306  and a horizontal axis  310 . In an embodiment, the measuring head  302  has a rotary mirror  312 , which may be rotated about a horizontal axis  310 . The rotation about the vertical axis may be about the center of the base  304 . In an embodiment, the vertical (azimuth) axis  306  and the horizontal (zenith) axis  310  intersect at the gimbal point  308 , which may be an origin of a coordinate system. 
     The measuring head  302  is further provided with an electromagnetic radiation emitter, such as light emitter  314  for example, that emits an emitted light beam  316 . In one embodiment, the emitted light beam  316  is coherent light, such as a laser beam for example. The laser beam may have a wavelength range of approximately 300 to 1600 nanometers, for example 790 nanometers, 905 nanometers, 1550 nm, or less than 400 nanometers. It should be appreciated that other electromagnetic radiation beams having greater or smaller wavelengths may also be used. The emitted light beam  316  may be amplitude or intensity modulated, for example, with a sinusoidal waveform or with a rectangular waveform. The emitted light beam  316  is emitted by the light emitter  314  onto the rotary mirror  312 , where it is deflected to the environment. A reflected light beam  318  is reflected from the environment by an object  320 . The reflected or scattered light is intercepted by the rotary mirror  312  and directed into a light receiver  322 . The directions of the emitted light beam  316  and the reflected light beam  318  result from the angular positions of the rotary mirror  312  and the measuring head  302  about the axis  306  and axis  310 , respectively. These angular positions in turn depend on the rotary drives that cause rotations of the rotary mirror  312  and the measuring head  302  about the axis  310  and axis  306 , respectively. Each of the axes  310 ,  306  include at least one angular transducer  324 ,  326  for measuring angle. The angular transducer may be an angular encoder. 
     Coupled to the light emitter  314  and the light receiver  322  is an electronic data processing system  500 . The electronic data processing system  328  determines, for a multitude of surface points X, a corresponding number of distances d between the laser scanner  300  and surface points X on object  320 . The distance to a particular surface point X is determined based at least in part on the speed of light in air through which electromagnetic radiation propagates from the device to the surface point X. In one embodiment the phase shift between the laser scanner  300  and the surface point X is determined and evaluated to obtain a measured distance “d”. In another embodiment, the elapsed time between laser pulses is measured directly to determine a measured distance “d.” 
     The speed of light in air depends on the properties of the air such as the air temperature, barometric pressure, relative humidity, and concentration of carbon dioxide. Such air properties influence the index of refraction n of the air. The speed of light in air is equal to the speed of light in vacuum “c” divided by the index of refraction. In other words, c air =c/n. A laser scanner of the type discussed herein is based on the time-of-flight of the light in the air (the round-trip time for the light to travel from the device to the object and back to the device). A method of measuring distance based on the time-of-flight of light (or any type of electromagnetic radiation) depends on the speed of light in air. 
     In an embodiment, the scanning of the volume about the laser scanner  300  takes place by quickly rotating the rotary mirror  312  about axis  310  while slowly rotating the measuring head  302  about axis  306 , thereby moving the assembly in a spiral pattern. For such a scanning system, the gimbal point  308  defines the origin of the local stationary reference system. The base  304  rests in a local stationary frame of reference. 
     Referring now to  FIG. 4 , an embodiment of a triangulation scanner  400  is shown that includes a light source  402  and at least one camera  404  and an electronic data processing system  500  that determines the three dimensional coordinates of points on the surface  410  of an object  408 . The triangulation scanner may the same as that described in commonly owned U.S. patent application Ser. No. 14/139,021 filed on Dec. 23, 2013, the contents of which are incorporated herein by reference. A triangulation scanner  400  is different than a laser tracker  200  or a TOF laser scanner  300  in that the three-dimensional coordinates are determined based on triangulation principals related to the fixed geometric relationship between the light source  402  and the camera  404  rather than on the speed of light in air. 
     In general, there are two common types of triangulation scanners  400 . The first type, sometimes referred to as a laser line probe or laser line scanner, projects the line or a swept point of light onto the surface  410 . The reflected laser light is captured by the camera  404  and in some instances, the coordinates of points on the surface  410  may be determined. The second type, sometimes referred to as a structured light scanner, projects a two-dimensional pattern of light or multiple patterns of light onto the surface. The three-dimensional profile of the surface  410  affects the image of the pattern captured by the photosensitive array  38  within the camera  404 . Using information collected from one or more images of the pattern or patterns, the electronic data processing system  406  can in some instances determine a one-to-one correspondence between the pixels of the photosensitive array in camera  404  and the pattern of light emitted by the light source  402 . Using this one-to-one correspondence together with a baseline distance between the camera and the projector, triangulation principals are used by electronic data processing system  500  to determine the three-dimensional coordinates of points on the surface  410 . By moving the triangulation scanner  400  relative to the surface  410 , a point cloud may be created of the entire object  408 . 
     In general, there are two types of structured light patterns, a coded light pattern and an uncoded light pattern. As used herein the term coded light pattern refers to a pattern in which three dimensional coordinates of an illuminated surface of the object are based on single projected pattern and a single corresponding image. With a coded light pattern, there is a way of establishing a one-to-one correspondence between points on the projected pattern and points on the received image based on the pattern itself Because of this property, it is possible to obtain and register point cloud data while the projecting device is moving relative to the object. One type of coded light pattern contains a set of elements (e.g. geometric shapes) arranged in lines where at least three of the elements are non-collinear. Such pattern elements are recognizable because of their arrangement. In contrast, as used herein, the term uncoded structured light pattern refers to a pattern that does not allow 3D coordinates to be determined based on a single pattern. A series of uncoded light patterns may be projected and imaged sequentially, with the relationship between the sequence of obtained images used to establish a one-to-one correspondence among projected and imaged points. For this embodiment, the triangulation scanner  400  is arranged in fixed position relative to the object  408  until the one-to-one correspondence has been established. 
     It should be appreciated that the triangulation scanner  400  may use either coded or uncoded structured light patterns. The structured light pattern may include the patterns disclosed in the journal article “DLP-Based Structured Light 3D Imaging Technologies and Applications” by Jason Geng published in the Proceedings of SPIE, Vol. 7932, which is incorporated herein by reference. 
     Collectively, the metrology instruments such as the AACMM  100 , the laser tracker  200 , the TOF laser scanner  300  and the triangulation scanner  400  are referred to herein as metrology devices. It should be appreciated that these metrology instruments are exemplary and the claimed invention should not be so limited, as the systems and methods disclosed herein may be used with any metrology instrument configured to measure three-dimensional coordinates of an object. 
       FIG. 5  is a block diagram of an embodiment of an electronic data processing system  500  utilized in metrology devices  100 ,  200 ,  300 ,  400  in accordance with an embodiment. The electronic data processing system  500  includes a base processor board  502  for implementing the base processing system, a communications module  526 , a base power board  506  for providing power, and a base tilt board  508 . As will be discussed in more detail below, the communications module  526  may include one or more sub-modules, such as a near field communications circuit (NFC), a cellular teleconference circuit (including LTE, GSM, EDGE, UMTS, HSPA and 3GPP cellular network technologies), a Bluetooth® (IEEE 802.15.1 and its successors) circuit and a Wi-Fi (IEEE 802.11) circuit for example. 
     In embodiments, the metrology device  100 ,  200 ,  300  includes one or more encoders, and the electronic data processing system  500  for the metrology device is in communication with the aforementioned plurality of encoder systems via one or more electrical busses  510 . The metrology device  100 ,  200 ,  300 ,  400  may further include an optical bus  520  in communication with the electronic data processing system  500 . It should be appreciated that the data processing system  500  may include additional components, such as connectors, terminals or circuits, for example, which are configured to adapt the incoming and outgoing signals to busses  510 ,  520 . For the clarity purposes, not all of these components are shown in  FIG. 5 . 
       FIGS. 6A-6B  are block diagrams describing features of the electronic data processing system  500  of the metrology device  100 ,  200 ,  300 ,  400  in accordance with an embodiment. In an embodiment, the electronic data processing system  500  is located internally within a housing of the metrology device and includes the base processor board  502  a base power board  506 , a communications module  526 , and a base tilt module  508 . 
     The base processor board  502  includes the various functional blocks illustrated therein. For example, a base processor function  522  is utilized to support the collection of measurement data from the metrology device and receives raw metrology data (e.g., encoder system or time of flight data), such as via electrical bus  510 . The memory function  523  stores programs and static metrology device configuration data. As will be discussed in detail below, in some embodiments the static configuration data may be stored in memory associated with an NFC module on the communications module  526 . The base processor board  502  may also include an external hardware option port functions for communicating with any external hardware devices or accessories such as but not limited to a graphical monitor or television via HDMI port, an audio device port, a USB 3.0 port and a flash memory (SD) card via port for example. 
     The base processor board  502  may also manage all the wired and wireless data communication with an external computing device. The base processor board  502  has the capability of communicating with an Ethernet network via a gigabit Ethernet function (e.g., using a clock synchronization standard such as Institute of Electrical and Electronics Engineers (IEEE) 1588), with a wireless local area network via communications module  526 . The communications module  526  may include a Bluetooth module  528 , a WiFi module  530  and a near field communications (NFC) module  532 . It should be appreciated that the communications module  526  may include other communications related circuits or modules and the modules described herein are exemplary and not intended to be limiting. 
     In the illustrated embodiment, the NFC module  532  is a dual-interface memory/tag device such as the M24SR series NFC tags manufactured by ST Microelectronics N.V. for example. A dual-interface memory device includes a wireless port that communicates with an external NFC reader, and a wired port that connects the device with another circuit, such as base processor board  502 . As will be discussed in more detail below, the use of a dual-interface memory device provides advantages allowing the NFC module  532  to interact with or control functionality of the base processing board  502 . In one embodiment, the NFC module  532  includes the boot load code, the executable code used by the processor  522  during operation initiation (initial power-on state of operation). By storing the boot load code in the memory of NFC module  532 , this executable code may be upgraded or replaced by the end-user using the NFC communications medium rather than involving service personnel. 
     In another embodiment, the NFC module  532  is a single port NFC tag, such as MIFARE Classic Series manufactured by NXP Semiconductors. With a single port tag, the module  532  is not electrically coupled to the base processor board  502 . In this embodiment, the NFC module  532  stores a set of device data regarding the metrology device, such as but not limited to: serial number, configuration, revision data or encoder identification data for example. This provides advantages in allowing the user or service personnel to quickly identify the metrology device. Further, this data may be used with a portable computing device to automatically associate the measurements made by the metrology device with the serial number of the instrument to allow tracing of the measurements to a particular instrument. It should be appreciated that in this embodiment, the NFC module  532  may be integrated onto the same board as the other modules as illustrated, or may be mounted separately. In one embodiment, the NFC module  532  is mounted to an adhesive label that is coupled to the outside of the metrology device. 
     Further, it should be appreciated that while  FIG. 6  illustrates the communications module as having a single connection, this is for exemplary purposes and the connections from the sub-modules  528 ,  530 ,  532  to the base processor board  502  may include several connections, such as but not limited to a parallel to serial communications (PSC) function. The base processor board  502  also includes a connection to a universal serial bus (USB 3.0) device  534 . 
     The base processor board  502  transmits and collects raw measurement data (e.g., encoder system counts, temperature readings) for processing into measurement data without the need for any preprocessing. As will be discussed in more detail herein, the base processor  502  sends the processed data to an external computing device via a wired Ethernet interface, USB interface  534  or communications module  526 . In an embodiment, the base processor  502  also sends the raw measurement data to the external computing device. 
     Turning now to the communications module  526 , this module allows the base processor  502  to wirelessly transmit and receive signals from one or more computing devices, such as a portable computing device. These portable computing devices may include but is not limited to a cellular phone, a tablet computer, a wearable computer or a laptop for example. The external wearable device may be, for example, glasses having a display that shows the user the data/information from the metrology device as described herein. The wearable device may also be a watch with a display that shows the user data/information from the metrology device. The wearable device may further be an article such as a badge, ring, broach or pendant that displays information from the metrology device. It should be appreciated that these wearable devices may also indicate or display a subset of the data/information, for example, a ring may have an indicator that changes color based on a measurement parameter (e.g. the measurement was successfully acquired). The wearable device and other portable computing devices each have a processor and memory that is configured to execute computer instructions on the respective processor to perform the functions described herein. 
     The communications module  526  may transmit the angle and positional data received by the base processor and utilize it with applications executing on a portable computing device to provide a portable and autonomous metrology system that operates with the metrology device. Applications may be executed on the portable computing device to support functions such as, but not limited to: measurement of features, guidance and training graphics, remote diagnostics, temperature corrections, control of various operational features, connection to various networks, and display of measured objects. 
     The electronic data processing system  500  may also include a base power board  506  with an environmental recorder  536  for recording environmental data. The base power board  506  also provides power to the electronic data processing system  500  using an AC/DC converter  538  and a battery charger control  540 . The base power board  506  communicates with the base processor board  502  using inter-integrated circuit (I2C) serial single ended bus as well as via a DMA serial peripheral interface (DSPI). The base power board  506  is connected to a tilt sensor  542  via an input/output (I/O) expansion function  544  implemented in the base power board  506 . 
     Though shown as separate components, in other embodiments all or a subset of the components may be physically located in different locations and/or functions combined in different manners than that shown in  FIG. 6 . For example, in one embodiment, the base processor board  502  is shielded to reduce radio frequency (RF) interference and the communications module board  526  is disposed outside of the shielding to allow communication with external devices. 
       FIG. 7  illustrates an embodiment of the NFC module  532  (sometimes colloquially referred to as an NFC tag or listening device) and an NFC reader  550  (sometimes colloquially referred to as a polling device). The term “near field communications” refers to a communications system that allows for a wireless communications between two devices over a short or close range, typically less than 5 inches (127 millimeters). NFC further provides advantages in that communications may be established and data exchanged between the NFC tag  532  and the reader  550  without the NFC tag  532  having a power source such as a battery. To provide the electrical power for operation of the NFC tag  532 , the reader emits a radio frequency (RF) field (the Operating Field). Once the NFC tag  532  is moved within the Operating Field, the NFC tag  532  and reader  550  are inductively coupled, causing current flow through an NFC tag antenna  552 . The generation of electrical current via inductive coupling provides the electrical power to operate the NFC tag  532  and establish communication between the tag and reader, such as through load modulation of the Operating Field by the NFC tag  532 . The modulation may be direct modulation, frequency-shift keying (FSK) modulation or phase modulation, for example. In one embodiment, the transmission frequency of the communication is 13.56 megahertz with a data rate of 106-424 kilobits per second. 
     In one embodiment, the NFC tag  532  includes a logic circuit  554  that may include one or more logical circuits for executing one or more functions or steps in response to a signal from the antenna  552 . It should be appreciated that logic circuit  554  may be any type of circuit (digital or analog) that is capable of performing one or more steps or functions in response to the signal from antenna  552 . In one embodiment, the logic circuit  554  may further be coupled to one or more memory devices  556  configured to store information that may be accessed by logic circuit  554 . NFC tags may be configured to read and write many times from memory  556  (read/write mode) or may be configured to write only once and read many times from memory  556  (card emulation mode). For example, where only static instrument configuration data is stored in memory  556 , the NFC tag may be configured in card emulation mode to transmit the configuration data in response to a reader device  550  being brought within range of the antenna  552 . 
     In addition to the circuits/components discussed above, in one embodiment the NFC tag  532  may also include a power rectifier/regulator circuit, a clock extractor circuit, and a modulator circuit. The Operating Field induces a small alternating current (AC) in the antenna when the reader is brought within range of the tag. The power rectifier and regulator converts the AC to stable DC and uses it to power the NFC tag, which immediately “wakes up” or initiates operation. The clock extractor separates the clock pulses from the Operating Field and uses the pulses to synchronize the logic, memory, and modulator sections of the NFC tag with the NFC reader. The logic circuit separates the 1&#39;s and 0&#39;s from the Operating Field and compares the data stream with its internal logic to determine what response, if any, is required. If the logic circuit determines that the data stream is valid, it accesses the memory section for stored data. The logic circuit encodes the data using the clock extractor pulses. The encoded data stream is input into the modulator section. The modulator mixes the data stream with the Operating Field by electronically adjusting the reflectivity of the antenna at the data stream rate. Electronically adjusting the antenna characteristics to reflect RF is referred to as backscatter. Backscatter is a commonly used modulation scheme for modulating data on to an RF carrier. In this method of modulation, the tag coil (load) is shunted depending on the bit sequence received. This in turn modulates the RF carrier amplitude. The NFC reader detects the changes in the modulated carrier and recovers the data. 
     In an embodiment, the NFC tag  532  is a dual-interface NFC tag, such as the aforementioned M24SR series NFC tags for example, having two ports, the antenna  552  for wireless communication and a wired port  558 . The wired port  558  may be coupled to transmit and receive signals from the processor  522  for example. In one embodiment, the memory  556  stores the boot load code for the processor  522 . As used herein the term “boot load code” or “boot loader code” is a set of computer program instructions that is loaded into the main memory  523  to initiate operation of the operating system on the processor  522  and the electronic data processing system  500 . The boot load code stored in NFC tag memory  556  may be a primary boot load code or a secondary boot load code. 
     It should be appreciated that while embodiments herein disclose the operation of the NFC tag  532  in a passive mode, meaning an initiator/reader device provides an Operating Field and the NFC tag responds by modulating the existing field, this is for exemplary purposes and the claimed invention should not be so limited. In other embodiments, the NFC tag  532  may operate in an active mode, meaning that the NFC tag  532  and the reader device  550  may each generate their own Operating Field. In an active mode, communication is performed by the NFC tag and reader device alternately generating an Operating Field. When one of the NFC tag and reader device is waiting for data, its Operating Field is deactivated. In an active mode of operation, both the NFC tag and the reader device may have its own power supply. 
     The reader device  550  is a portable or mobile computing device and may be a general computing device, such as a cellular (smart) phone or a tablet computer for example. The reader device  550  includes a processor  560  coupled to one or more memory modules  562 . The processor  560  may include one or more logical circuits for executing computer instructions. Coupled to the processor  560  is an NFC radio  564 . The NFC radio  564  includes a transmitter  566  that transmits an RF field (the Operating Field) that induces electric current in the NFC tag  532 . Where the NFC tag  532  operates in a read/write mode, the transmitter  566  may be configured to transmit signals, such as commands or data for example, to the NFC tag  532 . 
     The NFC radio  564  may further include a receiver  568 . The receiver  568  is configured to receive signals from, or detect load modulation of, the Operating Field by the NFC tag  532  and to transmit signals to the processor  560 . Further, while the transmitter  566  and receiver  568  are illustrated as separate circuits, this is for exemplary purposes and the claimed invention should not be so limited. In other embodiments, the transmitter  566  and receiver  568  may be integrated into a single module. The antennas being configured to transmit and receive signals in the 13.56 megahertz frequency. 
     Referring now to  FIGS. 1 and 8-10 , an embodiment is shown of the AACMM  100  cooperating with a mobile computing device, such as cellular phone  602 . The mobile computing device  602  may also be a smart pad, laptop computer, smart music player, or other type of device having a computer processor. It should be appreciated that while the illustrated embodiment is in reference to the AACMM  100 , these methods and processes may be similarly applied to other metrology devices, such as the laser tracker  200 , the TOF laser scanner  300  and the triangulation scanner  400  for example. In the exemplary embodiment, the cellular phone  602  includes a display  606  that presents a graphical user interface (GUI)  608  to the user. In one embodiment, the GUI  608  allows the user to view data, such as measured coordinate data for example, and interact with the cellular phone  602 . In one embodiment, the display  606  is a touch screen device that allows the user to input information and control the operation of the cellular phone  602  using their fingers. The cellular phone  602  further includes a processor  610  ( FIG. 10 ) that is responsive to executable computer instructions and to perform functions or control methods, such as those illustrated in  FIGS. 11-14 and 16  for example. The cellular phone  602  may further include memory  612 , such as random access memory (RAM) or read-only memory (ROM) for example, for storing application code that is executed on the processor  610  and storing data, such as coordinate data for example. The cellular phone  602  further includes communications circuits, such as near field communications (ISO 14443) circuit  614 , Bluetooth (IEEE 802.15.1 or its successors) circuit  550  and WiFi (IEEE 802.11) circuit  618  for example. The communications circuits  614 ,  616 ,  618  are transceivers, meaning each is capable of transmitting and receiving signals. It should be appreciated that the cellular phone may include additional components and circuits, such as a cellular communications circuit, as is known in the art. 
     The cellular phone  602  may further include additional modules or engines  620 , which may be in the form of application software or “apps” that execute on processor  610  and may be stored in memory  612 . In one embodiment, a trigger module  622  is provided that cooperates with the NFC circuit  550  to activate one or more modules  620  when the NFC circuit  550  is brought within range of another NFC enabled device, such as AACMM  100  for example. In one embodiment, the trigger module  622  initiates the transfer of application program interface (API) code  633  from the metrology device  100  to the cellular phone  602 . In one embodiment, the API code  633  may be transmitted by an embedded web server  631  ( FIG. 9 ) in the electronic data processing system  500 . In still another embodiment, the trigger module  622  initiates the downloading of an application or module (an “app”) from an online store or remote computing server when the desired module is not already installed on the device. The downloaded module then cooperates with the API code  633  to control one or more aspects of the metrology device. This provides advantages in that the size of the downloaded module may be reduced since the API&#39;s are stored on the metrology device. The downloaded module could include functionality such as controlling the 3D measuring instrument, collecting data from measurements made by the 3D measuring instruments, and displaying the results of data obtained from the metrology device. 
     The API code may be specific to the particular metrology device (such as AACMM  100 ) and specify for the cellular phone  602  how the components or modules  620  interact with each other and the metrology device. It should be appreciated that the API code for an AACMM  100  may be different than that for a laser tracker  200 . In one embodiment, the API code specifies a set of functions or routines that accomplish a specific task or are allowed to interact with a specific software component. For example, there may be calls to functions or routines, such as but not limited to: connecting with the metrology device, disconnecting from the metrology device, acquiring a measurement, capturing a point cloud, initiating a compensation process, and acquiring an image for example. 
     While embodiments herein describe the transfer of API code from the metrology device to the cellular phone  602  when the NFC communication is established, this is for exemplary purposes and the claimed invention should not be so limited. In other embodiments, the API code may be transferred from the metrology device as needed, such as when a user executes an application module for example. In still other embodiments, the API code is transferred by the web server  631  once a WiFi connection is established between the metrology device and the cellular phone  602 . 
     In still other embodiments, the API code is stored in a remote computer server. The remote computer server may be arranged on the local area network or in a distributed/cloud computer network. A computer network may include a wireless network, a hardwire network or a cellular telecommunications network. It should be appreciated that the remote computer server may be comprised of a plurality computers in a distributed computing configuration. Where the API code is stored on a remote computer server, advantages may be gained by allowing for updating of the API code without having to transfer to each individual instrument. Further, API code may be stored/acquired based on the serial number of the metrology device. This provides advantages in allowing the API code to reflect changes in the manufacturing builds be organized efficiently. Further, by establishing communication with the remote computer server, other computing functions such as processing the three-dimensional coordinate data may be performed on the remote computer server. 
     The module  620  may also include a communications module  624  that establishes communications with the AACMM  100  using Bluetooth circuit  618  or WiFi circuit  618  (e.g. IEEE 802.11) for example. With a Bluetooth circuit  618 , the communications module  624  establishes communication directly with the portable computing device. A WiFi circuit  618  on the other hand will communicate with the portable computing device via an access point that connects the WiFi circuit  618  to a local area network. It should be appreciated that the portable computing device may incorporate an access point that allows the transmission of signals directly to the portable computing device via the WiFi circuit  618 . The modules  620  may also include a parameters module  626 , which allow the operator to change settings and parameters, such as encoder parameters within the electronic data processing system  210  of AACMM  100 . For example, the parameters module  626  may allow the changing of the WiFi settings (e.g. power levels, approved networks, service set identifier or SSID). It may also include instrument parameters related with the characteristics of the individual instrument—for example, kinematic model parameters that might be distances, angles, offsets, and so forth. 
     The module  620  may further include a control or measurement module  628 . The measurement module  628  allows the user to issue commands, such as indicating the type of measurement being performed to the AACMM  100 . In one embodiment, the measurement module  628  may receive an inspection plan, meaning a series of measurements to be performed, and present the measurements to the user in the order defined by the inspection plan. In one embodiment, an NFC circuit or tag  532  is either attached to the object being inspected or its accompanying documentation. The cellular phone  602  retrieves the inspection plan by placing the NFC module  550  into proximity of the object NFC tag. The NFC tag is powered by the Operating Field generated by the NFC circuit  550  and the inspection plan is transmitted to the cellular phone  602 . Finally, in the exemplary embodiment, the module  620  may include a calibration module  630  that provides instructions to the user on carrying out calibration steps for the AACMM  100 . The calibration module  630  may also perform calculations to process measurement results obtained from the calibration procedure. 
     In the exemplary embodiment, the metrology device  100 ,  200 ,  300 , or  400  may include on the instrument a visual indicator of NFC capability. For example, in an AACMM  100 , the visual indicator may be provided on an area  604  of the base  116 . In one embodiment, the NFC module  532  or its antenna  552  is located proximate the area  604 . To couple the portable computing device  602  to communicate with the AACMM  100 , the device  602  is brought in proximity (e.g. less than 5 inches) to the area  604 . When within range, the Operating Field generated by the NFC circuit  550  induces current within the NFC module  532  to power the NFC module  532  via inductive coupling. Once powered the NFC module  532  transmits a signal to the device  602  causing the trigger module  622  to initiate operation of one or more modules within the module  620 . 
     Once the NFC module  550  and the NFC circuit  532  establish communication, this may allow for a series of automated or partially automated functions to occur that facilitate the operation of the metrology device by the user. In the embodiment of  FIG. 11 , a method  700  is provided that allows the establishment of communications between the portable computing device  602  and the AACMM  100 . The method  700  starts in block  702  where the user places the device  602  in proximity to the area  604 . The Operating Field created by the NFC circuit  550  induces a current in the NFC module  532  in block  704 , and in response a signal is transmitted to the NFC module  550  in block  706 , such as by modulation of the Operating Field. The receipt of the signal by the NFC module  550  in block  708  activates the trigger module  622 , which executes one or more modules  620 , such as the communications module  624  for example. As discussed above, the metrology device may also transmit API code to the device  602 . 
     In block  710 , the communication module  624  transmits signals to the NFC module  532  that include parameters to configure in block  712  communication between the device  602  and the metrology device (e.g. AACMM  100 ) using a communications protocol, such as cellular telecommunications (e.g. LTE), Bluetooth or WiFi, for example, that allows the user to maintain communication between the device  602  and the metrology device at greater distances than is allowed by NFC. This provides advantages in allowing the user to move the device  602  while maintaining communication with the metrology device during the measurement process. Once the communication channels are established, the method  700  proceeds to block  714  where a signal may be transmitted to the metrology device, such as with measurement module  628  for example. A function is executed by the metrology device, such as acquire a coordinate data on an object in block  716 . The data is then transmitted to the device  602  in block  718 , such as to display the coordinate data on the display  506  for example. 
     It should be appreciated that the ability to establish communications in a simple manner between the device  602  and the metrology device provides advantages in the set up and operation of the metrology device. For example, where a local area network or wireless network is not available (e.g. a construction site), the establishment of communications via the NFC tag could be used to initiate a process within the cellular phone to establish an ad-hoc WiFi network (e.g. a hotspot) for communication between different metrology devices. Further, this ad-hoc network could use the cellular data telecommunications capability (e.g. LTE) of the cellular phone to transmit and receive data from a remote computer server. 
     In still further embodiments, the establishment of communications via the NFC tag could be used to coordinate measurements performed by multiple metrology devices. In this embodiment, the device is brought into proximity with each of the metrology devices and establishes communications with each. The device is then used to control the collection of instruments and collect data as needed. In one embodiment, the device is used to determine one or more measurements that utilize data from a plurality of metrology devices. 
     In still further embodiments, the establishment of communications via the NFC tag could be extended to establish communications with other peripheral equipment and devices, such as robotic device or assembly line machinery for example. In this embodiment, having established communications with the metrology device and the peripheral equipment could quickly and simply establish control and coordination of the operation. 
     In another embodiment shown in  FIG. 12 , a method  720  provides for the updating of parameters in the metrology device. In this embodiment, communication between the device  602  and the metrology device is established in blocks  702 ,  704 ,  706 ,  708  as described herein above. In this embodiment, the trigger module  622  may initiate activation of the parameters module  622 . With the parameters module  622  operating on the device  602 , the user selects or enters the data parameters that need to be updated or changed on the metrology device in block  722 . The updated parameters are transmitted to the metrology device in block  724 . In one embodiment, the parameters are stored in the metrology device memory  523  in block  726 , such as in the NFC module  532  or in memory  556  for example. It should be appreciated that the transfer of parameters from the device  602  to the metrology device may be performed through the NFC communications medium, the Bluetooth communications medium or the WiFi communications medium. For example, a Wifi parameter may include the set-service identifier (SSID) of the wireless network, or the acceptable power output of the WiFi radio. Further, it should be appreciated that when the parameters module  622  is executed, the current settings of metrology device may be transmitted to the device  602  for review by the user prior to updating or changing of the settings. It should be appreciated that this provides advantages in allowing the metrology device to be quickly configured to comply local regulatory requirements. For example different jurisdictions have different output power limitations for wireless communications circuits (e.g. WiFi). Typically manufacturers create different model instruments that are preconfigured to comply with the different regulatory requirements. Embodiments of the present invention provide advantages in allowing the metrology device to be quickly configured, either prior to shipping from the manufacturer or at the location of use via a mobile general purpose computing device, such as a cellular phone. 
     Referring now to  FIG. 13 , another embodiment is shown for updating the boot load code that initiates operation of the metrology device. In this embodiment, a method  730  starts in block  732  with the metrology device in the powered off state of operation. The method  730  then proceeds to block  734  where the NFC module  532  is activated via inductive coupling as described herein above. When the NFC module  532  is powered, a signal is transmitted to the NFC circuit  550  in block  736 . The trigger module  622  initiates the execution of an update module on the device  602  in block  738 . The update module transmits to the NFC module  532  the updated boot load code in block  740  and the new boot load code is stored in memory  556  in block  742 . It should be appreciated that in this embodiment, the boot load code is stored in the NFC module  532  since the base processor board  502  is unpowered. Therefore, the executable code used by the processor  522  during the initiation or boot process is obtained from the NFC module  532  when the metrology device is powered on in block  744  and booted in block  746 . In one embodiment, the memory used in the NFC module  532  is but not limited to universal serial bus, 1-wire, inter-integrated circuit (I2C) or a serial peripheral interface (SPI) types of memory. In one embodiment, the boot load code is a first level code used to initiate or boot the processor  522 . In another embodiment, the boot load code is a secondary level code that is executed by the processor  522  after initial activation. 
     Referring now to  FIG. 14 , another embodiment is shown of a method  748  for operating the metrology device with the device  602  in accordance with an inspection plan. Method  748  starts in block  750  by storing an inspection plan on an object NFC tag. As used herein, the term “inspection plan” refers to a set or series of measurements that are performed on the object, such as to determine if the object was manufactured within the desired specifications for example. The object NFC tag may be directly coupled to the object (e.g. an adhesive label) or may be coupled to an associated item, such as a bin, a tote, a box, an engineering drawing or other documentation for example. The method  748  then proceeds to block  752  where the object NFC tag is activated by the device  602 . The method  748  then transmits the inspection plan to the device  602  in block  754 . The user then moves the device  602  in proximity to metrology device and activates the NFC module  532  in block  486  and communication between the device  602  and the metrology device is established in block  758  as described herein above. The device  602  then displays on the display  606  instructions on a measurement, or a series of measurements for the object that the user is to acquire using the metrology device in block  760 . In one embodiment, the instructions are displayed sequentially in the order they are to be performed. In another embodiment, the instructions are displayed as a group or list and the user selects the measurements prior to performing the measurement with the metrology device. 
     The user then performs the measurement (e.g. flatness of a surface, diameter of a hole or surface, etc.) or determines three-dimensional coordinate data in block  762 . In query block  764 , it is determined whether there are any additional measurements to be performed. If query block  764  returns a positive, the method  748  loops back to block  760  and the next measurement in the inspection plan is displayed and acquired. If query block  764  returns a negative, the method  748  proceeds to block  766  where the acquired data is stored. In some embodiments, the device  602  may download from the web server  631  of the metrology device additional APIs required to complete the inspection plan. 
     It should be appreciated that components within the metrology device may incorporate NFC tags. For example, as shown in  FIGS. 15-16 , in an embodiment, the metrology device is an AACMM  100  and each of the bearing cartridge groupings  110 ,  112 ,  114  includes one or more NFC tags  770 . As discussed above, each of the bearing cartridge groupings  110 ,  112 ,  114  includes one or more rotary encoders that measure the amount of rotation of an axis of a bearing cartridge. These encoders include device data, such as a unique identification number or address relative to the other encoders in the AACMM. This identification number is transmitted with the rotary data to the electronic data processing system  210 . In this way, the electronic data processing system  210  may determine which encoder transmitted the positional signal and the 3-D positional calculations may be determined. Further, during the manufacturing process, each of the encoders is measured and calibrated. This calibration data may be utilized by the AACMM  100  in compensating the 3D measurements. Further, by providing an NFC tag  770 , the calibration data may be stored with the encoder and therefore more reliably tracked and applied by the AACMM  100 . 
     Typically, in prior art systems, the identification number was assigned to an encoder using a manual dual in-line package (DIP) switch. As a result, when an encoder is replaced, the installer needs to determine identification number or address of the encoder and manually assign the new encoder with the same identification number. In the exemplary embodiment, the identification number for the encoder is stored in the NFC tag  770 . Thus, by placing the device  602  adjacent the NFC circuit  500 , the operator may determine the identification number of the encoder. Further, in one embodiment, the NFC circuit  770  is a read-write type of NFC circuit. This also provides advantages in allowing the operator to change the identification number of the encoder. 
     Referring now to  FIG. 16 , a method  772  for assigning an identification-number/address to an encoder. The method  772  starts with activating the NFC tag  770  with the device  602  in block  774 . The NFC tag  500  then transmits a signal to the device  602  in block  776  which causes trigger module  622  to execute an application module on the device  602  for communicating with an NFC tag in block  778 . The user selects or enters an encoder identification number using the application module in block  780 . The new identification number is transmitted to the NFC tag  770  in block  782 . The new identification number is stored in the NFC tag  770  memory in block  784  where it may be accessed by the encoder during operation of the AACMM  100 . 
     Another exemplary embodiment is shown in  FIG. 17A and 17B  of an NFC tag being used with a metrology device, such as AACMM  100 , for communicating between two components that move relative to each other. In this embodiment, the AACMM  100  is a six-axis coordinate measurement machine. In a six-axis AACMM, the bearing cartridge  812  only rotates about a single axis  800  and there is no rotation of the probe end  401  about the centerline  802 . However, in some embodiments, the probe housing  814  includes a grip portion  804  that freely rotates about the centerline  802 . It should be appreciated that this arrangement facilitates the user holding the probe end  401  in a comfortable position during operation. It also facilitates redirecting a beam of light from a line scanner attached to the end of the articulated arm, should one be present. Mounted on the grip portion  804  are one or more actuators  806 ,  808 . These actuators allow the operator to activate different functions of the metrology device, such as taking a measurement for example. 
     In one embodiment, each actuator  806 ,  808  includes an NFC tag  532 A,  532 B coupled to a switch  810 A,  810 B. The switches  810 A,  810 B are arranged as part of the antenna circuit  552 A,  552 B of each NFC tag  532 A,  532 B. An NFC reader  550  is arranged in the probe housing  102  adjacent the actuators  806 ,  808 , such that NFC reader  550  remains stationary relative to the grip portion  804 . In other words, the grip portion, and therefore the actuators  806 ,  808 , rotate about the NFC Reader  550 . The switches  810 A,  810 B are configured to be in a “normally open” position, meaning that the switches  810 A,  810 B form an open circuit unless the respective actuator  806 ,  808  is depressed or actuated by the operator. Thus, when the actuators  806 ,  808  are actuated, the switches  810 A,  810 B are closed allowing the respective antenna circuits  552 A,  552 B to be formed. 
     The NFC reader  550  continuously emits an Operating Field during operation. When the actuators  806 ,  808  are not actuated by the operator, the open switches  810 A,  810 B prevent inductive coupling. Thus, the NFC tags  532 A,  532 B are not powered and no signal is transmitted by the NFC tags  532 A,  532 B. Once an actuator  806 ,  808  is actuated, the antenna circuit for the respective NFC tag is closed. The NFC tag then modulates the Operating Field to signal the NFC reader  550  that the actuator has been actuated. As a result, the NFC reader  550  may transmit a signal to the electronic data processing system  206  indicating that the respective actuator  806 ,  808  has be actuated. It should be appreciated that the coupling of the NFC tags to a movable body member has advantages in allowing signals indicating the activation of an actuator on the movable body member to be transmitted wirelessly without the need for expensive and complicated slip rings. Thus the costs of the AACMM  100  may be reduced while also improving reliability. 
     It should be appreciated that while embodiments herein describe communication between the AACMM  100  and the portable computing device  602 , this is for exemplary purposes and the claimed invention should not be so limited. In another embodiment, the NFC module  532  may be used to couple the AACMM with a portable accessory, such as but not limited to a laser line probe, a laser scanner, or a retroreflector for example. The NFC module  532  may also be used to establish communication with accessories coupled to the probe end  401  for example. The communication between the AACMM  100  and the accessories via the NFC communications medium may allow the AACMM  100  to set parameters or settings within the accessory, or may synchronize the accessory clock with that of the AACMM for example. 
     It should be appreciated that while embodiments described herein make reference to an AACMM, the claimed invention should not be so limited. In other embodiments, the NFC circuits may be used with other metrology instructions, such as but not limited to laser trackers, laser scanners and laser line probes for example. In one embodiment, an NFC circuit may be implemented in a laser tracker and a retroreflector to allow the serial number of the retroreflector to be automatically associated with data acquired by the laser tracker for example. 
     In an embodiment, a rotary switch device is provided. The rotary switch including a housing have an axis of rotation. A first actuator is coupled to the housing. A first switch is coupled to the first actuator, the first actuator being configured to selectively close the first switch. A first electrical circuit is provided. A first antenna circuit is electrically coupled the first switch to the first electrical circuit, wherein the first electrical circuit and first antenna circuit cooperate to modulate an operating field when the first switch is closed. A reader circuit is arranged fixed relative to the axis of rotation, the reader circuit including a transmitter configured to emit the operating field and a receiver configured to detect the modulated operating field. 
     In an embodiment, the first electric circuit and the first antenna circuit are inductively coupled when the first switch is in the closed position. The reader circuit may be configured to transmit a signal in response to detecting modulation of the operating field. In an embodiment, the rotary switch may further comprise a second actuator coupled to the housing. A second switch may be coupled to the second actuator, the second actuator being configured to selectively close the second switch. A second electric circuit is provided having a second logic circuit. A second antenna circuit is electrically coupled the second switch to the second electric circuit, wherein the second electric circuit and second antenna circuit cooperate to modulate the operating field when the second switch is closed. 
     In another embodiment, a portable articulated arm coordinate measuring machine (AACMM), is provided. The AACMM includes a manually positionable articulated arm having opposed first and second ends, the arm including a plurality of connected arm segments, each of the arm segments including at least one position transducer for producing a position signal. An electronic processing system is electrically coupled to receive the position signals. A probe end is coupled to the first end, the probe end having a housing coupled to the first end to rotate about an axis. A measurement device is coupled to the housing and electrically coupled to the electronic processing system. A first actuator is coupled to the housing. A first switch is coupled to the first actuator, the first actuator being configured to selectively close the first switch. A first electric circuit is provided. A first antenna circuit is electrically coupled to the first switch to the first electric circuit, wherein the first near field communication circuit and first antenna circuit cooperate to modulate an operating field when the first switch is closed. A reader circuit is arranged fixed relative to the axis of rotation, the reader circuit including a transmitter configured to emit the operating field and a receiver configured to detect the modulated operating field. 
     In an embodiment, the first switch is a normally open type switch. The first electric circuit and the first antenna circuit may be inductively coupled when the first switch is in the closed position. The reader circuit may be configured to transmit a measurement signal to the electronic processing system in response to detecting modulation of the operating field. In an embodiment, the AACMM further comprises a second actuator coupled to the housing. A second switch is coupled to the second actuator, the second actuator being configured to selectively close the second switch. A second electric circuit is provided. A second antenna circuit is electrically coupled to the second switch to the second electric circuit, wherein the second electric circuit and second antenna circuit cooperate to modulate the operating field when the second switch is closed. In another embodiment, the measurement signal is transmitted from the reader circuit to the electronic processing system, the electronic processing system providing data corresponding to a position of the measurement device in response to the measurement signal. 
     In another embodiment, a method of conveying information with a portable articulated arm coordinate measuring machine (AACMM) is provided. The method including the steps of: providing a manually positionable articulated arm portion having opposed first and second ends, the arm portion including a plurality of connected arm segments, each of the arm segments including at least one position transducer for producing a position signal; providing a probe end coupled to the first end, the probe end having a housing arranged to rotate about an axis of rotation, the probe end further having a switch coupled to rotate with the housing, the switching being electrically coupled to a first electric circuit by an antenna circuit, the probe, the probe end further having a reader circuit fixedly arranged relative to the axis of rotation, wherein the electric circuit is arranged to move about the reader circuit; providing a measurement device coupled to the housing; providing an electronic processing system for receiving the position signals from the transducers and for determining a position of the measurement device; emitting an operating field with the reader circuit; closing the switch; modulating the operating field with the electric circuit and antenna circuit in response to the closing of the switch; transmitting a measurement signal to the electronic processing system in response to the reader circuit detecting the modulation of the operating field; and determining the three-dimensional coordinates of the measurement device with the electronic processing system in response to receiving the measurement signal. 
     In an embodiment, the method may further include inductively coupling the reader circuit with the antenna circuit and electric circuit in response to the switch being closed. In an embodiment, the method may further include providing a second switch coupled to the housing. A second electric circuit is disposed to rotate about the reader circuit. A second antenna circuit is electrically coupled the second switch and to the second electric circuit, wherein the second electric circuit and second antenna circuit cooperate to modulate the operating field when the second switch is closed. 
     In an embodiment, the method further includes inductively coupling the reader circuit, the second antenna circuit and the second electric circuit in response to the second switch being closed. In an embodiment, the method further includes transmitting a second measurement signal to the electronic circuit in response to the switch being closed. 
     Technical effects and benefits include providing a contactless switch without the use of slip rings for a device having a housing with switches that rotates about an axis such as on the probe end of an articulated arm coordinate measurement machine. The technical effects and benefits further include the improved reliability and a lower cost switch. 
     Aspects of the present invention are described herein with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and/or block diagrams, and combinations of blocks in the flowchart illustrations and/or block diagrams, can be implemented by computer readable program instructions. 
     These computer readable program instructions may be provided to a processor of a general purpose computer, special purpose computer, 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 flowchart and/or block diagram block or blocks. These computer readable program instructions may also be stored in a computer readable storage medium that can direct a computer, a programmable data processing apparatus, and/or other devices to function in a particular manner, such that the computer readable storage medium having instructions stored therein comprises an article of manufacture including instructions which implement aspects of the function/act specified in the flowchart and/or block diagram block or blocks. 
     The computer readable program instructions may also be loaded onto a computer, other programmable data processing apparatus, or other device to cause a series of operational steps to be performed on the computer, other programmable apparatus or other device to produce a computer implemented process, such that the instructions which execute on the computer, other programmable apparatus, or other device implement the functions/acts specified in the flowchart and/or block diagram block or blocks. 
     The flowchart and block diagrams in the Figures illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to various embodiments of the present invention. In this regard, each block in the flowchart or block diagrams may represent a module, segment, or portion of instructions, which comprises one or more executable instructions for implementing the specified logical function(s). 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. It will also be noted that each block of the block diagrams and/or flowchart illustration, and combinations of blocks in the block diagrams and/or flowchart illustration, can be implemented by special purpose hardware-based systems that perform the specified functions or acts or carry out combinations of special purpose hardware and computer instructions. 
     While the invention has been described in detail in connection with only a limited number of embodiments, it should be readily understood that the invention is not limited to such disclosed embodiments. Rather, the invention can be modified to incorporate any number of variations, alterations, substitutions or equivalent arrangements not heretofore described, but which are commensurate with the spirit and scope of the invention. Additionally, while various embodiments of the invention have been described, it is to be understood that aspects of the invention may include only some of the described embodiments. Accordingly, the invention is not to be seen as limited by the foregoing description, but is only limited by the scope of the appended claims. Moreover, the use of the terms first, second, etc. do not denote any order or importance, but rather the terms first, second, etc. are used to distinguish one element from another. Furthermore, the use of the terms a, an, etc. do not denote a limitation of quantity, but rather denote the presence of at least one of the referenced item.