ANT Message Protocol and Usage

Transcription

1 ANT Messge Protocol nd Usge D Rev 2.9 Dynstrem Innovtions Inc. July 2, 2007 P F

2 2 of 68 Copyright Informtion nd Usge Notice This informtion disclosed herein is the exclusive property of Dynstrem Innovtions Inc. No prt of this publiction my be reproduced or trnsmitted in ny form or by ny mens including electronic storge, reproduction, execution or trnsmission without the prior written consent of Dynstrem Innovtions Inc. The recipient of this document by its retention nd use grees to respect the copyright of the informtion contined herein. The informtion contined in this document is subject to chnge without notice nd should not be construed s commitment by Dynstrem Innovtions Inc. unless such commitment is expressly given in covering document. The Dynstrem Innovtions Inc. ANT Products described by the informtion in this document re not designed, intended, or uthorized for use s components in systems intended for surgicl implnt into the body, or other pplictions intended to support or sustin life, or for ny other ppliction in which the filure of the Dynstrem product could crete sitution where personl injury or deth my occur. If you use the Products for such unintended nd unuthorized pplictions, you do so t your own risk nd you shll indemnify nd hold Dynstrem nd its officers, employees, subsidiries, ffilites, nd distributors hrmless ginst ll clims, costs, dmges, nd expenses, nd resonble ttorney fees rising out of, directly or indirectly, ny clim of personl injury or deth ssocited with such unintended or unuthorized use, even if such clim lleges tht Dynstrem ws negligent regrding the design or mnufcture of the Product Dynstrem Innovtions Inc. All Rights Reserved.

3 3 of 68 Revision History Revision Effective Dte Description 1.0 April 9, 2005 Preliminry Version Relese 1.31 April 29, 2005 Externl Relese 2.0 December 6, 2005 Description of shred chnnel brodcst ddress, new event codes, ddition of vrious exmples nd other minor updtes 2.1 September 18, 2006 Deleted brodcst cknowledged nd burst chnnel events from the tble. 2.2 November 14, 2006 Added new messges for relese 2.3 Mrch 30, 2007 Added SensRcore messge support 2.4 April 24, 2007 Added Scnning Chnnel Detils 2.5 My 28, 2007 Added Extended Dt Messge Description 2.6 June 7, 2007 Updted EVENT tble nd dded tble describing which events re vilble on which products. 2.7 June 27, 2007 Minor fixes 2.8 July 2, 2007 Document formt chnge 2.9 July 6, 2007 Document formt chnge

4 4 of 68 Tble of Contents 1 Introduction The ANT Product Fmily Network topologies ANT Nodes ANT Chnnels Chnnel Configurtion Network RF Frequency Chnnel ID Chnnel Type Chnnel Period Dt Types & Dt Formt Exmple Chnnel Configurtion Independent Chnnels Shred Chnnels Scnning Chnnels Estblishing chnnel Device Piring Piring Exmple ANT Interfce Messge Structure Host MCU Seril Interfce Physicl Lyer Host PC Seril Interfce Exmple ANT Network Implementtion Implementtion using Independent Chnnels Chnnel between Node B nd Node A Chnnel between Node C nd Node A Chnnel between Node D nd Node A Implementtion using Shred Chnnels Appendix A ANT Messge Detils ANT Messges Config Messges Control Messges Dt Messges Chnnel Event/Response Messges Requested Response Messges Test Mode ANT Messge Structure - Notes ANT Messge Summry ANT Product Cpbilities Interfce Events ANT Messge Detils ANT Constnts Configurtion Messges Control Messges Dt Messges Chnnel Response / Event Messges Requested Response Messges Test Mode Extended Dt Messges PC Functionl Interfce Configurtion ANT Librry Access Appendix B -- SensRcore NVM Messge Detils SensRcore NVM Messges NVM Messge Summry Seril NVM Messges...66

5 5 of 68 1 Introduction ANT is 2.4GHz bidirectionl wireless Personl Are Network (PAN) communictions technology optimized for trnsferring low-dt rte, low-ltency dt between multiple ANT-enbled devices. The ultr-low power consumption of the ANT chipset gurntees n extended bttery life even from low-cpcity supplies such s coin cell bttery, enbling use in hert rte monitors, bicycle computers, nd wrist wtches. ANT s smll size nd low implementtion cost llows effortless integrtion into the tiny form fctor of wrist wtches, PDAs, nd mobile phones. ANT provides crefree hndling of the Physicl, Network nd Trnsport OSI lyers. In ddition, it incorportes key low-level security fetures tht form the foundtion for user-defined sophisticted network security implementtions. ANT ensures dequte user control while considerbly lightening computtionl burden in providing simple yet effective wireless networking solution. Appliction / Presenttion Lyers Higher Level Security User Defined Network / Trnsport & Low Level Security Dt Link Lyer Physicl Lyer Implemented by ANT Figure 1-1: OSI Lyer model of ANT The interfce between ANT nd the Host ppliction hs been designed with the utmost simplicity in mind so tht ANT cn be esily nd quickly implemented into new devices nd pplictions. The encpsultion of the wireless protocol complexity within the ANT chipset vstly reduces the burden on the ppliction host controller, llowing low-cost 4-bit or 8-bit Microcontroller (MCU) to estblish nd mintin complex wireless networks. Dt trnsfers cn be scheduled in deterministic or d-hoc fshion. A burst mode llows for the efficient trnsfer of lrge mounts of stored dt to nd from PC or other computing device. The ANT system ggressively blnces functionlity, cost, size, nd power consumption within the constrints of mobile Personl Are Network. Typicl pplictions include sensor integrtion, tgging systems, remote monitoring, etc. A typicl ANT-enbled device consists of n ppliction host MCU interfced with n ANT module or chipset. The host MCU estblishes nd mintins communiction session to other remote ANT-enbled devices by mens of simple, bidirectionl, seril messge protocol. This document detils the protocol nd provides exmples of how to use ANT for wireless networking.

6 6 of 68 2 The ANT Product Fmily ANT technology hs been incorported into fmily of products tht llows prticulr implementtion to be scled to suit the needs of the ppliction nd the vision of the product designer. ANT technology is vilble in the following formts. ANT Single Chip & Chipset Intended for integrtion onto the customer s PCB nd interfced with host MCU. 1. Nordic Semiconductor nrf24ap1 A complete ANT implementtion integrted into single-chip RF protocol nd trnsceiver Integrted Circuit (IC). 2. Two-chip ANT solutions combine n ANT-protocol MCU with Nordic Semiconductor RF IC (such s the nrf2401a or nrf24l01). A vriety of two-chip options re vilble, providing either onewy or two-wy RF communictions, llowing the protocol to be scled with the needs of the ppliction. The two-chip solutions provide the ultimte in low power consumption. ANT Module A certifiction redy PCB module incorportes n ANT chipset nd cn be piggybcked onto n existing PCB, llowing for immedite product integrtion with miniml effort. ANT USB Stick The ANT USB Stick provides bridge between n ANT network nd PC. ANT USB comes with roylty-free drivers which cn be redistributed with ANT. ANT Development Kit Development Kits re vilble to provide timely nd efficient pth to ANT integrtion for both the embedded nd PC environments. The embedded environment offers esy integrtion with custom hrdwre. The PC environment provides USB interconnection long with drivers nd smple pplictions. ANT PC Interfce Softwre A roylty-free PC softwre librry provides n interfce to the ANT USB Stick nd ANT Development Kit, nd is redily integrted with customer s PC ppliction.

7 7 of 68 3 Network topologies The ANT protocol hs been designed from the ground up to support lrge rnge of sclble network topologies. It cn be s simple s 2-node unidirectionl connection between trnsmitting peripherl device nd receiver, or s complex s multi-trnsceiver system with full point-to-multipoint communiction cpbilities. Simple Networks Complex Networks Independent Networks Brodcst Networks Shred Chnnel Networks Figure 3-1: Exmple ANT Networks For the purpose of illustrtion, simple exmple is shown next to demonstrte the bsic concept of ANT chnnels.

8 8 of 68 Sensor 1 Chnnel A Chnnel C Hub 1 Hub 2 Chnnel B Sensor 2 Figure 3-2: A Simple ANT Network ANT usge nd configurtion re chnnel-bsed. Ech ANT node (represented by circle) cn connect to other ANT nodes vi dedicted chnnels. Ech chnnel generlly connects two nodes together; however single chnnel cn in fct connect multiple nodes. Ech chnnel hs s minimum single mster nd single slve prticipnt. The mster cts s the primry trnsmitter; the slve cts s the primry receiver. In Figure 3-2, lrge rrows indicte the primry dt flow from mster to slve, with smll rrows indicting reverse messge flow (e.g. Chnnel B, C). A chnnel with single rrow (e.g. Chnnel A) is used to represent one-wy link, which supports the use of lower-cost trnsmit-only nodes. Note tht n ANT node cn ct s both slve (e.g. Hub1 chnnel A, B) nd mster (e.g. Hub1 chnnel C) simultneously. The following tble describes the mster / slve sttus of ech of the chnnels shown in Figure 3-2 Chnnel Mster Slve Chnnel A Sensor1 (TX-Only) Hub1 (RX) Chnnel B Sensor2 (TX) Hub1 (RX) Chnnel C Hub1 (TX) Hub2 (RX)

9 9 of 68 4 ANT Nodes Ech node in n ANT network consists of n ANT protocol engine nd host controller (MCU). The ANT engine encpsultes the complexity of estblishing nd mintining ANT connections nd chnnel opertion within its firmwre. The host controller is thus free to hndle the prticulrs of n ppliction with only limited burden in inititing ANT communictions to other nodes, which it does vi simple seril interfce between host nd ANT engine, s shown in the following digrm. Node Node Host MCU Seril Interfce Ant Engine Figure 4-1: Contents of n ANT node

10 10 of 68 5 ANT Chnnels In this section, further detils re presented bout the ANT protocol s most fundmentl building block: the chnnel. As previously discussed, chnnel must be estblished to connect two nodes together. Node1 Chnnel A Node2 Node1 Node2 Host1 Host2 Ant1 Chnnel A Ant2 Mster Slve Figure 5-1: Chnnel communiction between two ANT nodes A chnnel consists of: A mster (e.g. Node1) A slve (e.g. Node2) 5.1 Chnnel Configurtion In order for two ANT devices to communicte, they require common chnnel configurtion tht includes informtion relted to the operting prmeters of chnnel. The following informtion is required to define chnnel configurtion. Network RF Frequency Trnsmission Type Device Type Chnnel Type Chnnel Period Dt Types

11 11 of 68 Dt Formt Although the configurtion of specific chnnel will likely remin constnt throughout its connection, mster cn mintin multiple chnnels tht differ in terms of chnnel configurtion prmeters Network ANT supports the estblishment of numerous unique public nd privte networks. A prticulr network my specify set of operting rules for ll prticipting nodes. In order for two ANT devices to communicte, they must be members of the sme network. This provides the bility to estblish network tht cn be purposely shred mong multiple vendors with the gol of estblishing n open system of interoperble devices. Conversely, privte network could be defined to ensure network privcy nd restrict ccess to intended prticipting devices. Chnnels cn be independently ssigned to different networks so tht it is possible for single ANT device to be member of multiple networks. The ANT Network hs two components which re described below Network Number The Network Number is n 8-bit field with the rnge of cceptble vlues being from 0 to the mximum number defined by the ANT implementtion. It cn be obtined by the host by querying the ANT system using the pproprite request messge. Plese refer to Section 9 for more detils. The defult Network Number is Network Key The Network Key is n 8-byte field which is configurble by the host ppliction. A prticulr Network Number will hve corresponding Network Key. The Network Number nd the Network Key together provide the bility to deploy network with vried levels of ccess control nd security options. By defult ANT firmwre ssigns the Network Number 0 with the defult Public Network Key. This network is open to ll prticipting devices nd hs no set rules governing its use. For more informtion on estblished public networks or inititing your own network, plese contct Dynstrem t RF Frequency ANT technology supports the use of ny of the vilble 125 unique RF operting frequencies. A chnnel will operte on single frequency throughout its existence, which must be known nd dhered to by both mster nd slve prior to the estblishment of chnnel. The RF frequency is n 8-bit field with cceptble vlues rnging from 0 to 124. This vlue represents the offset in 1MHz increments from 2400MHz, with the mximum network frequency being 2524MHz. For exmple, if network operting frequency of 2450MHz ws desired, the RF frequency field will be set s 50. Desired _ RF _ Frequency( MHz) 2400MHz RF _ Frequency _ vl = 1MHz The following eqution cn be used to determine the vlue for the RF frequency field.

12 12 of 68 The defult RF frequency field vlue is 66 nd represents the network operting frequency of 2466MHz. It is importnt to note tht it is not necessry to use different RF frequencies to support multiple coexisting chnnels. The TDMA nture of the ANT system mens tht lrge number of chnnels cn coexist on single common RF frequency. It is the product developer s responsibility to ensure tht RF frequencies used will comply with the regultions of ll regions of the world in which this equipment is to be used Chnnel ID The most bsic descriptor of chnnel is its chnnel ID. In order to estblish n ANT chnnel, the host must specify its chnnel ID. It s 4-byte homogenous vlue tht contins 3 fields Trnsmission Type, Device Type nd Device Number. They re detiled below Trnsmission Type The trnsmission type is n 8-bit field used to define certin trnsmission chrcteristics of device. Exmple usge is the SensRcore implementtion which defines the two lest significnt bits of the trnsmission type to define the presence nd size of shred ddress field t the beginning the dt pylod, nd bit 3 defines the next byte following the ddress field Device Type The device type is n 8-bit field used to denote the type of ech prticipting network device. This field is used to differentite between multiple nodes of network devices so tht prticipnts re wre of the vrious clsses of connected nodes nd cn decode received dt ccordingly. For exmple, hert rte monitor will be ssigned different device type thn bike speed sensor nd the hert rte monitor s dt pylod will be interpreted ccordingly. A receiver node my communicte to multiple device types but its device type must be set to 0. Plese note tht the most significnt bit of the Device Type is used to control device piring. More informtion on device piring cn be found in Section 6. Specific implementtion-level informtion bout chnnel ID usge is provided in the chnnel ID functionl description locted in Section Device Number The device number is 16-bit field tht is ment to be unique for given device type. Typiclly, this my be correlted to the seril number of the device or could be rndom number generted by the device if the process of setting seril numbers for prticulr product is unvilble. This field my lso be used s wild crd during device piring s described in the chnnel ID functionl description locted in Section Chnnel Type Chnnel type specifies the type of communiction tht will occur on the chnnel. It is n 8-bit field with only certin cceptble vlues in the rnge of 0 to 255. The vlues re specified in the tble below.

13 13 of 68 Vlue 0x00 0x10 0x20 0x30 0x40 0x50 Description Bidirectionl Receive Chnnel Bidirectionl Trnsmit Chnnel Shred Bidirectionl Receive Chnnel Shred Bidirectionl Trnsmit Chnnel Receive Chnnel with option to not cler wild crd upon successful mtch. Trnsmit Only Chnnel Note tht the chnnel type must be specified prior to estblishing chnnel. For bidirectionl chnnel type, the dt flow for the forwrd chnnel is determined by the mode specified. For exmple, if node estblishes bidirectionl receive chnnel type, it will ssume the role of the receiver on the forwrd chnnel nd hs the potentil to trnsmit on the reverse chnnel. Plese refer to Sections nd , below, for more informtion on the concept of forwrd nd reverse chnnels Chnnel Period The chnnel period represents the bsic messge rte of dt pckets sent by the mster. By defult brodcst dt pcket will be sent or received on every timeslot t this rte. The chnnel messge rte cn rnge from 0.5Hz to bove 200Hz with the upper limit being implementtion specific. The defult messge rte is 4Hz, which is chosen to provide good performnce s described below. It is recommended tht the messge rte be left t the defult to provide more redily discoverble networks with good performnce chrcteristics. The chnnel period is 16-bit field with its vlue determined s shown in the following eqution Chnnel _ Period _ vl = MessgeRte( Hz) For exmple, to hve messge rte of 4Hz on chnnel, the chnnel period vlue must be set to / 4 = The mximum messge rte (or the minimum chnnel period) depends on the computtionl cpcity of the system. High dt rtes in combintion with multiple ctive chnnels will substntilly limit the mximum messge rte. Proper ssignment of chnnel period is criticl nd it is impertive to be mindful of the following issues. The messge rte is directly proportionl to the power consumption. Plese see respective ANT product dtsheet for detils. A smll chnnel period llows for higher dt-trnsfer rtes. A smll chnnel period results in fster successful device-serch opertions Dt Types & Dt Formt The chnnel dt type determines the type of communiction tht will occur between the prticipnts of tht chnnel. The dt type is specified by the host ppliction using the messge ID field of the seril messge tht it provides to the ANT system. Plese refer to Section 7 for more detils on the seril interfce between host nd ANT.

14 14 of 68 The overll communiction hs two levels one governs the direction (mster to slve or vice vers) nd the second specifies the type. They re described in detil in the following sections Forwrd Chnnel Communiction (Mster Slve) Dt messges re trnsmitted from the mster to slve on every chnnel timeslot. Three bsic dt types re supported which re listed below. 1. Brodcst 2. Acknowledged 3. Burst Brodcst Dt Brodcst dt is the most bsic dt type nd is the system defult. Brodcst dt is sent from the chnnel mster to the slve on every chnnel timeslot. This form of dt is never cknowledged, nd so the chnnel mster will be unwre in the cse of lost dt pckets. In the cse of one-wy trnsmission link (trnsmit-only node communicting to receiver), brodcst dt is the only vilble dt type due to the inbility of n cknowledgement. Brodcst dt consumes the lest mount of RF bndwidth nd system power consumption. It is the preferred choice of communiction where occsionl dt loss is not criticl (though it should be noted tht ny dt loss will be very limited in most non-hostile RF environments). An exmple system where occsionl dt loss is not criticl is tht of temperture logging system, where chnges in temperture re reltively slow compred to the communictions messge rte. Brodcst dt is sent t every time slot of the messge period. If no new dt hs been provided by the host, the previous messge is re-trnsmitted Acknowledged Dt At ny time during n estblished two-wy connection, the mster cn choose to send n cknowledged dt pcket in plce of brodcst dt pcket. The slve will respond to the cknowledged dt pcket with n cknowledgment messge bck to the mster. The mster s host controller will be notified of ech cknowledged dt pcket s success or filure. The host my choose to send every dt pcket s cknowledged dt, or mix brodcst nd cknowledged dt s pproprite to the prticulr ppliction. Acknowledged dt pckets use more RF bndwidth nd consume more power, which should be tken into considertion when designing power-sensitive pplictions. Acknowledged dt is idelly suited for the trnsmission of criticl control dt where 100% dt trnsmission integrity is required. There is no utomtic re-trnsmission of uncknowledged dt pckets. If the dt type isn t specified s Acknowledged or if no new dt is provided before the trnsmit time slot, the messge is sent s Brodcst dt type Burst Dt Burst dt trnsmission provides mechnism for the mster to send lrge mounts of dt to the slve. A burst trnsction begins t the next scheduled timeslot, nd consists of series of continuous

15 15 of 68 cknowledged dt messges from mster to slve. Any lost messges re utomticlly retrnsmitted. There is no limit on the durtion of burst trnsction. A burst trnsction tkes precedence over ll other chnnels on both prticipting nodes. If there re other chnnels in the system, cre should be tken to service them with resonble frequency. Although the ANT protocol is robust nd cn hndle outges cused by burst trnsfers or other externl interference, excessive chnnel strvtion my led to undesirble behvior Reverse Chnnel Dt (Slve Mster) At the end of every chnnel timeslot, the slve my optionlly send dt to the mster. The sme three bsic dt types s described in Section (Mster Slve) re supported. 1. Brodcst 2. Acknowledged 3. Burst Brodcst Dt Brodcst dt is sent from the slve to the mster t the end of chnnel timeslot if expressly requested by the Host MCU of the slve (without request, no dt is sent by defult). As is the cse for the forwrd chnnel, this form of dt is never cknowledged, nd so the chnnel slve will be unwre in the cse of lost dt pckets. Brodcst messges re sent only once on the reverse chnnel. In other words, there is no brodcst messge sent on every time slot of the messge period in the reverse chnnel s opposed to the forwrd chnnel Acknowledged Dt At ny time during n estblished two-wy connection, the slve cn optionlly choose to send n cknowledged dt pcket to the mster t the end of chnnel timeslot. The mster will respond to ny cknowledged dt pcket with n cknowledgment in the form of vlid receipt of the pcket. The slve s host controller will be notified of ech cknowledged dt pcket s success or filure. The slve will still lwys know if the cknowledged dt pcket hs successfully completed. Similr to the forwrd chnnel, there is no utomtic re-trnsmission of uncknowledged dt pckets Burst Dt Bulk dt my be sent from the slve to the mster in much the sme wy s described from mster to slve in Section (forwrd chnnel). A reverse burst trnsfer will commence t the end of the forwrd chnnel timeslot. The host ppliction softwre on both the mster nd slve sides should be implemented to expect common dt type (i.e. brodcst vs. cknowledged vs. burst) to be utilized s pproprite for prticulr ppliction. The specific formt of the contents of the dt pylod must be previously estblished by both host controllers such tht dt cn be properly decoded nd interpreted Exmple Chnnel Configurtion Below is n exmple of chnnel configurtion for simple ppliction.

16 16 of 68 Prmeter Vlue Description Network Type 0 Defult Public Network RF Frequency 66 Defult Frequency 2466MHz Device Number 1 Smple Seril Number Trnsmission Type 1 Trnsmission Type (no shred ddress) Device Type 1 Smple Device Type Chnnel Type 0x10 Bidirectionl Trnsmit Chnnel Chnnel Period Hz Messge Rte Dt Type 0x4E Brodcst 5.2 Independent Chnnels An independent chnnel hs only one mster nd one slve. It is possible for the mster or the slve to be mster or slve to nother or number of other nodes. But from the point of view of n independent chnnel, there is only one of ech. For exmple, consider the four-node network in Figure 3-2. All chnnels hve only one mster nd one slve. A brodcst network shown in Figure 3-1 is lso formed using independent chnnels even though the dt from one mster is received by mny slves. Such network hs unique mster who doesn t purposely initite communiction with multiple slves on the sme chnnel. Although independent chnnels offer simplicity in implementtion node cn only support limited number of simultneous independent chnnels within the confines of the system s computtionl bility. For exmple, the nrf24ap1 cn support 4 independent chnnels. For n implementtion exmple using independent chnnels, refer to Section Shred Chnnels Shred chnnels cn be used where single ANT node must receive nd possibly process dt from mny nodes. In this scenrio, multiple nodes will shre single independent chnnel to communicte with the centrl node. An exmple of shred chnnel network is provided in Figure 3-1. Shred chnnels re mde possible by the use of two-byte Shred Chnnel Address field nd specific vlue for the Chnnel Type; both re controlled by the host ppliction. The Shred Chnnel Address field replces the first two bytes of the dt pylod provided by the host ppliction to ANT if chnnel is defined s being shred chnnel. A shred chnnel cn support more thn slve devices using single independent chnnel. In shred chnnel network, the node tht is required to estblish communiction with mny other nodes must initite the shred chnnel s the mster. All other nodes tht need to ccess this shred chnnel must be configured s the slves. The chnnel must be configured s shred chnnel t ll nodes, mster or slve, tht my ccess tht chnnel. The mster controls the communiction by providing the Shred Chnnel Address in its forwrd chnnel messge. A slve will respond on the reverse chnnel only if its Shred Chnnel Address mtches the one it receives in the forwrd chnnel messge from the mster. In either the mster or the slve node, messges re relesed to the host ppliction only if the Shred Chnnel Address of the received messge mtches wht the ANT system is configured to respond to t the time or if the Shred Chnnel Address is 0. Typiclly, the slve will only be configured once to respond to prticulr Shred Chnnel Address. However, the mster will require continuous reconfigurtion if communiction with multiple slves over the shred chnnel is desired. The mster cn send dt to ll slves t the sme time using the Shred Chnnel Address of 0.

17 17 of 68 The shred chnnel concept is extensible to cknowledged dt nd burst dt trnsctions. In burst dt trnsctions, only the 1 st dt pcket requires the Shred Chnnel Address in the dt pylod, the remining dt pckets my contin only the ppliction dt. Plese refer to Section 8.2 for smple network implementtion using shred chnnels. 5.4 Scnning Chnnels Scnning chnnels re nother method tht cn be used where single ANT node must receive nd possibly process dt from mny nodes. In this scenrio, multiple nodes, setup s trnsmitters, will brodcst on single RF frequency to communicte with the centrl node which receives full time. An exmple of scnning chnnel network would be conceptully similr to tht of the shred chnnel network provided in Figure 3-1. In scnning chnnel, the node tht is required to estblish communiction with mny other nodes is setup s receiver tht is continuously ctive. Due to this configurtion, this node drws significnt power (~18 ma) s its RF is ctive continuously. The trnsmit nodes should hve unique device numbers in the chnnel ID so tht messges cn be correlted to specific devices esily. 5.5 Estblishing chnnel The following steps must be tken in order to properly estblish communiction chnnel between two ANT nodes. The prerequisite for estblishing chnnel is tht the mster nd the slve must hve common knowledge of the chnnel configurtion s outlined in Section 5.1. Procedure: 1. Prior to estblishing chnnel, the mster selects its intended network type, operting frequency, nd messge rte. 2. The mster estblishes the chnnel by trnsmitting 8-byte pylod dt pckets in prticulr timeslot t the estblished messge rte. The ANT chnnel will be mintined indefinitely t the given timeslot nd messge rte. The chnnel mster s host controller will optionlly provide new dt pylods to the ANT engine for continuing trnsmissions. 3. The slve selects the network type, operting frequency, nd messge rte of the mster from which it ll ttempt to receive. 4. The slve estblishes new ANT chnnel by serching for the intended unique mster. 5. Once the mster hs been locted, connection is estblished, nd the slve receives dt indefinitely from the mster t the given timeslot nd messge rte.

18 18 of 68 6 Device Piring The ct of piring two devices (mster with slve) involves estblishing reltionship between two nodes tht wish to communicte with one nother in future communiction sessions. This reltionship cn be permnent, semi-permnent or trnsitory. A piring opertion consists of slve device cquiring the unique ID of the mster device. If permnent piring is desired, the slve node should store the mster s ID to be used to open chnnel with this ID in ll subsequent communiction sessions. In semi-permnent sitution, the slve my wish to occsionlly purge ny stored ID nd pir with new mster. In trnsitory sitution, the slve my pir with mster on temporry bsis only. Plese note tht if mster uses only brodcst messging, or if it uses the shred chnnel feture, multiple slves my pir nd communicte with the sme mster. Estblishing chnnel involves the brodcsting of unique ID by the mster, nd serch nd cquisition of this ID by slve. In the cse where slve does not hve knowledge of specific mster ID, piring mechnism is vilble. The slve cn serch for mster with wild crd ID; upon successful serch result the specific ID of the mster cn be stored nd used in the sme mnner s previously described for ll future communictions. 6.1 Piring Exmple An exmple of piring opertion on network of three remote temperture sensors (msters) nd one bse unit (slve) is shown in Figure 6-1. Temp Sensor 1 Chnnel 0 Bse Unit Chnnel 2 Temp Sensor 3 Temp Sensor 2 Chnnel 1 Figure 6-1: Exmple ANT Network for use in Device Piring The bse unit wishes to estblish permnent reltionship with ll temperture sensors. To initite the piring opertion, ech temperture sensor should be plced into piring mode. From user perspective, it is left to the ppliction to define the method of entry into piring mode for exmple this could be done upon initil insertion of bttery, or by mens of button push by the user, etc. As fr s the ANT seril messge interfce is concerned, the host controller invokes piring mode by sending the following messges to the ANT engine (See Section 9.3 for detils):

19 19 of Configure Chnnel 2. Set Chnnel ID (discoverble) 3. Open TX Chnnel 4. Begin trnsmitting dt on its timeslot At this time, the bse unit (slve) must be prepred to serch for the ID of the pproprite device type (temperture sensor). It performs the following: 1. Configure Chnnel 2. Set Chnnel ID (Trnsmission Type = Specific or Wild crd, Device Type = Temperture sensor with Piring Bit Set, Device Number = Wild Crd) 3. Open RX Chnnel The bse unit finds temperture sensor ID s reported by the slve ANT engine to the host controller; the ID is stored by the host controller for future chnnel estblishment. This procedure is repeted for ll three temperture sensors. The temperture sensor cn then choose to disble its discoverbility fter time-out period (or fter connection cknowledgement from the bse unit if bidirectionl trnsmission is supported) in order to be invisible to future discovery by other slve devices. This piring process is required only once for the lifetime of n ANT system if permnent reltionship between two specific devices is desired. In such cse, piring my be performed during product mnufcturing (fctory environment) to remove the burden from the customer.

20 20 of 68 7 ANT Interfce The host ppliction nd ANT communicte through simple seril interfce. The host cn tke the form of n embedded microcontroller or PC, but the bsic functionlity remins unchnged. 7.1 Messge Structure A typicl seril messge between the host nd ANT engine hs the following bsic formt. SYNC MSG LENGTH MSG ID DATA_1 DATA_2... DATA_N CHECKSUM Figure 7-1: ANT Seril Messge Structure As shown bove, ech messge begins with SYNC byte nd ends with CHECKSUM. The bytes re sent LSBit first. The following tble describes ech component of the seril messge shown bove. Byte # Nme Length Description 0 SYNC 1 Byte Fixed vlue of (MSB:LSB) 1 MSG LENGTH 1 Byte Number of dt bytes in the messge. 1 < N < 9 2 MSG ID 1 Byte Dt Type Identifier 0: Invlid : Vlid Dt Type (See Section 9 for detils) 3..N+2 DATA_1..DATA_N N Bytes Dt bytes N+3 CHECKSUM 1 Byte XOR of ll previous bytes including the SYNC byte A complete summry of supported messges between host nd the ANT engine is presented in Section 9. The tble is vlid for both types of ANT interfces of Host MCU ANT, nd Host PC Interfce ANT. Messge formtting is first presented in summry form, which includes messge length, ID nd dt fields of ech respective messge type. Plese note tht the multi-byte fields hve been implemented in little endin formt. Using the exmple of Chnnel ID messge, the lest significnt byte of Device Number is ssigned to Dt1, nd the most significnt byte to Dt Host MCU Seril Interfce Physicl Lyer The ANT seril interfce between host controller nd ANT engine cn be implemented over either synchronous or synchronous connection. The connection type is selected by the product designer s preferred for the given implementtion. The precise detils of the physicl nd electricl interfce of ech ANT product cn be found in ech respective ANT product dtsheet. 7.3 Host PC Seril Interfce The primry method of communiction between ANT nd PC is through the ANT PC Interfce Librry. The components of this librry re listed in Section 9. 8 Exmple ANT Network Implementtion A smple network implementtion to present the fetures of the ANT engine is shown in Figure 8-1 below.

21 21 of 68 Node D Node A Node C Node B Figure 8-1: Exmple ANT Network for implementtion The simple four-node network describes n ppliction where informtion from multiple nodes (B, C nd D) is to be received nd possibly nlyzed by single centrl node (A). The rrows indicte the primry flow of informtion between the corresponding nodes. The following cn be ssumed. Node B is to use the brodcst dt type Node D is to use the brodcst dt type Node C requires the cknowledged dt type All of the network prerequisites, such s network type, device ID, RF Frequency etc. re known between ll nodes Device piring hs lredy been performed between the msters nd their corresponding slves Sections 8.1 nd 8.2 describe two methods of utilizing ANT to deploy the bove exmple network. 8.1 Implementtion using Independent Chnnels Using independent chnnels is the simplest method by which the forementioned network cn be implemented. Given the bove ssumptions, three independent chnnels re required. The configurtion for ech chnnel is shown in the following tbles. Chnnel between Node B nd Node A where Node B will be the mster:

22 22 of 68 Node Prmeter Vlue Description Network Type 0 Defult Public Network RF Frequency 66 Defult Frequency 2466MHz Device Number 1 Seril Number of Node B B A Trnsmission Type 1 Trnsmission Type (no shred ddress) Device Type 1 Device Type of Node B Chnnel Type 0x10 Bidirectionl Trnsmit Chnnel Chnnel Period 8192 Defult 4Hz Messge Rte Dt Type 0x4E Brodcst Network Type 0 Defult Public Network RF Frequency 66 Defult Frequency 2466MHz Device Number 1 Seril Number of Node B Trnsmission Type 1 Trnsmission Type (no shred ddress) Device Type 1 Device Type of Node B Chnnel Type 0x00 Bidirectionl Receive Chnnel Chnnel Period 8192 Defult 4Hz Messge Rte Dt Type 0x4E Brodcst Chnnel between Node C nd Node A where Node C will be the mster: Node Prmeter Vlue Description Network Type 0 Defult Public Network RF Frequency 66 Defult Frequency 2466MHz Device Number 10 Seril Number of Node C C A Trnsmission Type 1 Trnsmission Type (no shred ddress) Device Type 2 Device Type of Node C Chnnel Type 0x10 Bidirectionl Trnsmit Chnnel Chnnel Period 8192 Defult 4Hz Messge Rte Dt Type 0x4F Acknowledged Network Type 0 Defult Public Network RF Frequency 72 Frequency 2472MHz Device Number 10 Seril Number of Node C Trnsmission Type 1 Trnsmission Type (no shred ddress) Device Type 2 Device Type of Node C Chnnel Type 0x00 Bidirectionl Receive Chnnel Chnnel Period 8192 Defult 4Hz Messge Rte Dt Type 0x4F Acknowledged Chnnel between Node D nd Node A where Node A will be the mster:

23 23 of 68 Node Prmeter Vlue Description Network Type 0 Defult Public Network RF Frequency 66 Defult Frequency 2466MHz Device Number 2 Seril Number of Node D D A Trnsmission Type 1 Trnsmission Type (no shred ddress) Device Type 1 Device Type of Node D Chnnel Type 0x10 Bidirectionl Trnsmit Chnnel Chnnel Period 8192 Defult 4Hz Messge Rte Dt Type 0x4E Brodcst Network Type 0 Defult Public Network RF Frequency 66 Defult Frequency 2466MHz Device Number 2 Seril Number of Node D Trnsmission Type 1 Trnsmission Type (no shred ddress) Device Type 1 Device Type of Node D Chnnel Type 0x00 Bidirectionl Receive Chnnel Chnnel Period 8192 Defult 4Hz Messge Rte Dt Type 0x4E Brodcst Section detils the sequence of events nd messge trnsctions between the host nd ANT for ech prticipting node s the bove chnnels re estblished nd the network is formed. Refer to Section 5.4 for more informtion on the procedure for estblishing chnnel Chnnel between Node B nd Node A The chnnel between Node B nd Node A is estblished s follows. Mster: Node B The host issues the ANT_AssignChnnel() messge with the configurtion fields filled s mentioned in the tble bove. The chnnel number is ssigned t the discretion of the host. The host issues the ANT_SetChnnelID() messge with the configurtion fields filled s mentioned in the tble bove. The chnnel number is the sme s step 1. The host opens the chnnel using the ANT_OpenChnnel() messge. The host provides ANT with dt s it sees fit using the ANT_SendBrodcstDt() messge. Plese note tht the frequency t which the host provides ANT with new dt my not be the sme s the chnnel period. ANT will trnsmit the sme dt if no new dt is mde vilble by the host. However, pproprite sfegurds to ccount for such repeted messges should be in plce on the slve. Slve: Node A The host issues the ANT_AssignChnnel() messge with the configurtion fields filled s mentioned in the tble bove. The chnnel number is ssigned t the discretion of the host. The host issues the ANT_SetChnnelID() messge with the configurtion fields filled s mentioned in the tble bove. The chnnel number is the sme s in the previous step.

24 24 of 68 The host opens the chnnel using the ANT_OpenChnnel() messge. The host will now be informed using the ChnnelEventFunc(Chn, EV) type messge from ANT whenever the messge from Node B is received. Bsed on the chnnel configurtion settings, this will hppen t 1Hz Chnnel between Node C nd Node A The chnnel between Node C nd Node A is estblished s follows. Mster: Node C The host issues the ANT_AssignChnnel() messge with the configurtion fields filled s mentioned in the tble bove. The chnnel number is ssigned t the discretion of the host. The host issues the ANT_SetChnnelID() messge with the configurtion fields filled s mentioned in the tble bove. The chnnel number is the sme s in step 1. The host opens the chnnel using the ANT_OpenChnnel() messge. The host provides ANT with ppliction dt tht is to be sent through the chnnel s n cknowledged messge using the ANT_SendAcknowledgedDt() messge. ANT then communictes the success or filure of the trnsction bck to the host using messge code embedded inside chnnel event messge. If ANT doesn t receive n cknowledge bck from the slve, it will not utomticlly resend the messge. The host must process the filure messge code nd hndle the retries itself. Plese refer to the Appendix for list of the vrious messge codes. Slve: Node A The host issues the ANT_AssignChnnel() messge with the configurtion fields filled s mentioned in the tble bove. The chnnel number is ssigned t the discretion of the host. The host issues the ANT_SetChnnelID() messge with the configurtion fields filled s mentioned in the tble bove. The chnnel number is the sme s in the previous step. The host opens the chnnel using the ANT_OpenChnnel() messge. The host will now be informed using the ChnnelEventFunc(Chn, EV) type dt messge whenever n cknowledged messge is received from Node C. The cknowledgement of the received messge is hndled within ANT; hence the host only needs to process or use the received dt. The messges re received t the rte specified by the chnnel configurtion settings Chnnel between Node D nd Node A The procedure for estblishing the chnnel t Node D is exctly the sme s tht of Node B. The host of Node C will open third chnnel to communicte with Node B in the sme wy s for Node A. The bove ANT network will continue to function s it ws deployed unless n ppliction lyer event dicttes otherwise. 8.2 Implementtion using Shred Chnnels Another method by which the network shown in Figure 8-1 cn be implemented is with the use of single shred chnnel insted of three independent chnnels. The trde-off is the incresed computtionl burden on the host of the network hub (Node A) nd the reduction in the mount of mximum useful dt per pcket from 8 bytes to 6 bytes.

25 25 of 68 As mentioned in the description of shred chnnels erlier, the min receiver will become the mster of the shred chnnel with the trnsmitters its slves. Ech slve will hve unique two-byte shred chnnel ddress which will be known only to itself nd the mster. Moreover, ll nodes on the shred chnnel network will hve to be trnsceivers, s opposed to the independent chnnel implementtion where nodes B nd D could be trnsmit only. The updted network digrm for this setup is shown below. Node A Mster Shred Chnnel Node B Slve Node D Slve Shred Chnnel Address = 1 Shred Chnnel Address = 3 Node C Slve Shred Chnnel Address = 2 Figure 8-2: Shred chnnel implementtion of smple network The chnnel configurtion for ech node is shown in the tble below. Slve Node B Prmeter Vlue Description Network Type 0 Defult Public Network RF Frequency 66 Defult Frequency 2466MHz Device Number 3 Seril Number of Node A Trnsmission Type 3 Trnsmission Type (2 byte shred ddress) Device Type 3 Device Type of Node A Chnnel Type 0x20 Shred Receive Chnnel Chnnel Period 2370 ~12Hz Messge Rte Dt Type 0x4E Brodcst

26 26 of 68 Slve Node C Prmeter Vlue Description Network Type 0 Defult Public Network RF Frequency 66 Defult Frequency 2466MHz Device Number 3 Seril Number of Node A Trnsmission Type 3 Trnsmission Type (2 byte shred ddress) Device Type 3 Device Type of Node A Chnnel Type 0x20 Shred Receive Chnnel Chnnel Period 2370 ~12Hz Messge Rte Dt Type 0x4F Acknowledged Slve Node D Prmeter Vlue Description Network Type 0 Defult Public Network RF Frequency 66 Defult Frequency 2466MHz Device Number 3 Seril Number of Node A Trnsmission Type 3 Trnsmission Type (2 byte shred ddress) Device Type 3 Device Type of Node A Chnnel Type 0x20 Shred Receive Chnnel Chnnel Period 2370 ~12Hz Messge Rte Dt Type 0x4E Brodcst Mster Node A Prmeter Vlue Description Network Type 0 Defult Public Network RF Frequency 66 Defult Frequency 2466MHz Device Number 3 Seril Number of Node A Trnsmission Type 3 Trnsmission Type (2 byte shred ddress) Device Type 3 Device Type of Node A Chnnel Type 0x30 Shred Trnsmit Chnnel Chnnel Period 2370 ~12Hz Messge Rte Dt Type 0x4E Brodcst Plese note: The Network Type, RF Frequency, Device Number, Trnsmission Type nd Device Type re controlled by the mster (Node A). All slves tht wnt to use this shred chnnel must dhere to these prmeters. The ppliction-level chnnel periods re the sme for Node B (4Hz), Node C (4Hz) nd Node D (4Hz) s they were in the implementtion using independent chnnels. However, the mster needs the shred chnnel to operte t 12Hz (the sum of the messge rtes of ll slve nodes) t the very lest to suffice the requirements for ech slve. Since there is only one shred chnnel, ll slves will hve to bide by the rules of the chnnel initited by the mster. Hence, they will hve to estblish chnnels with the sme

27 27 of 68 messge rte s the mster. However, the host of ech of the slve nodes cn still communicte with ANT t only 4Hz. The following steps need to be tken for implementing the 4-node ANT network using single shred chnnel. Mster: Node A The host issues the ANT_AssignChnnel() messge with the configurtion fields filled s shown in the tble bove. The chnnel number is ssigned t the discretion of the host. The host issues the ANT_SetChnnelID() messge with the configurtion fields filled s shown in the tble bove. The chnnel number is the sme s in step 1. The host ssigns the chnnel s messge rte using the ANT_SetChnnelPeriod() messge nd the vlue listed in the bove tble. The host opens the chnnel using the ANT_OpenChnnel() messge. The host provides ANT with n ANT_SendBrodcstDt() messge, with the first two dt bytes representing the shred chnnel ddress of the slve to which the next RF messge is ddressed. ANT informs the host ech time messge is received on the reverse chnnel of the RF messge tht ws sent to the slve with the corresponding shred chnnel ddress. For this prticulr network, ech slve would send messge bck to the mster Node A ech time its shred chnnel ddress ppers. Slve: Node B The host issues the ANT_AssignChnnel() messge with the configurtion fields filled s shown in the tble bove. The chnnel number is ssigned t the discretion of the host. The host issues the ANT_SetChnnelID() messge with the configurtion fields filled s shown in the tble bove. The chnnel number is the sme s in step 1. The host sets the chnnel period using the ANT_SetChnnelPeriod() to the sme messge rte s the mster Node A. The host opens the chnnel using the ANT_OpenChnnel() messge. The host sends single Send_BrodcstDt() messge with the first two bytes s the shred chnnel ddress of Slve Node B to configure ANT to listen to the messges tht re ddressed to Slve Node B. The host will now be informed ech time ANT receives messge from the mster on the chnnel tht hs the shred chnnel ddress of Node B. For this ppliction, the host would provide dt to ANT to be sent bck to the mster on the reverse chnnel using the ANT_SendBrodcstDt() messge t 4Hz rte. ANT will send the dt on the reverse chnnel whenever it receives the properly ddressed messge on the forwrd chnnel. Slve: Node C The host issues the ANT_AssignChnnel() messge with the configurtion fields filled s shown in the tble bove. The chnnel number is ssigned t the discretion of the host. The host issues the ANT_SetChnnelID() messge with the configurtion fields filled s shown in the tble bove. The chnnel number is the sme s in step 1.

28 28 of 68 The host sets the chnnel period using the ANT_SetChnnelPeriod() to the sme messge rte s the mster Node A. The host opens the chnnel using the ANT_OpenChnnel() messge. The host sends single Send_BrodcstDt() messge with the first two bytes s the shred chnnel ddress of Slve Node C to configure ANT to listen to the messges tht re ddressed to Slve Node C. The host will now be informed ech time ANT receives messge from the mster on the chnnel tht hs the shred chnnel ddress of Node C. For this ppliction, the host would provide dt to ANT to be sent bck to the mster on the reverse chnnel using the ANT_SendAcknowledgedDt() messge t 4Hz rte. ANT will send the dt on the reverse chnnel whenever it receives the properly ddressed messge on the forwrd chnnel. A chnnel event messge from ANT informs the host if n cknowledgement is received from the mster or if the dt is sent bck successfully. Slve: Node D The procedure is similr to the slve Node B procedure. The difference is tht ANT will be configured to inform the host when it receives messge with the shred chnnel ddress of Node D. The bove two network implementtions re to be used s mens for gining fmilirity with network design nd deployment using ANT. The smple network could be implemented in other more efficient wys using vrious dvnced fetures of ANT. In generl, n ppliction will govern the method of implementtion tht is best suited for its needs.

29 29 of 68 9 Appendix A ANT Messge Detils 9.1 ANT Messges A summry of the vrious messges tht comprise the seril interfce between ANT nd host is provided in Section Config Messges The ANT configurtion messges llow the Host to set or chnge vrious prmeters of chnnel, such s the network, device type, trnsmission type, messge rte, RF frequency etc. These messges re the first step in enbling system for ANT communiction Control Messges After desirble configurtion of n ANT chnnel or chnnels, the control messges provide method for supervising the RF s well the ctivity of the ANT system Dt Messges The finl step in estblishing ANT communiction, the dt messges form the bsic input nd output of dt from n ANT node. In typicl ppliction, the Host will spend most of its ANT specific time on hndling dt messges Chnnel Event/Response Messges The chnnel event/response messges re comprised of notifictions nd dt tht re sent from ANT to the Host. These include RF events tht occur on chnnel s well s messges tht provide informtion bout the stte of the ANT system Requested Response Messges The Host is ble to obtin informtion from ANT using request messges. ANT replies to the requests using response messges. These include summry of the cpbilities, version informtion nd sttus of chnnels Test Mode ANT lso ccepts specil test mode messges which llow the product developer or tester to verify proper opertion of the RF hrdwre but plcing ANT in RF CW mode. 9.2 ANT Messge Structure - Notes The From column in Section 9.3 denotes the direction of dt flow. An entry of ANT indictes dtflow from ANT Host. An entry of Host indictes dtflow from Host ANT. The Response column in Section 9.3 indictes whether ANT will send response messge to the respective commnd.