The Application Level Events (ALE) Specification, Version 1.0 - GS1

More documents

Recommendations

Info

295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 not necessarily the case. The output of a read cycle is the input to the ALE layer; i.e., it is the interface between the Raw Tag Read Layer and the ALE Layer in the diagram of Section 2. As was noted earlier, this interface could be an actual software or network interface between a reader device and a middleware implementation, but this is not necessarily the case. From the ALE perspective, a read cycle is a single event containing a set of EPCs, with nothing more implied. An event cycle is one or more read cycles, from one or more Readers that are to be treated as a unit from a client perspective. It is the smallest unit of interaction between the ALE interface and a client. Referring to the diagram of Section 2, clients in the Application Business Logic Layer specify the boundaries of event cycles to the ALE layer as part of a request for a report. A report is data about an event cycle communicated from the ALE implementation to a client. The report is the output of the ALE layer, communicated to the Application Business Logic Layer. As tags or other carriers of EPC data move in and out of the detection zone of a Reader, the EPCs reported in each read cycle change. Within an event cycle, the same tag may be read several times (if the tag remains within the detection zone of any of the Readers specified for that event cycle). Section 8.2.1 specifies how event cycle boundaries may: • Extend for a specified duration (interval of real time); e.g., accumulate reads into five-second intervals. • Occur periodically; e.g., report only every 30 minutes, regardless of the read cycle. • Be triggered by external events; e.g., an event cycle starts when a pallet on a conveyer triggers an electric eye upstream of a portal, and ends when it crosses a second electric eye downstream of a portal. • Be delimited when no new EPCs are detected by any Reader specified for that event cycle for a specified interval of time. • Simply be every read cycle. (This possibility is not provided for in Section 8.2, but may be available through vendor extensions.) A client must specify one of these methods when requesting a report. (The complete set of available options is described normatively in Section 8.2.1.) The net picture looks something like this: Copyright © 2005, 2004 EPCglobal Inc, All Rights Reserved. Page 10 of 71
EPC1 EPC2 EPC3 EPC1 EPC2 EPC4 EPC3 EPC5 EPC3 EPC5 EPC3 EPC4 EPC5 EPC3 EPC5 EPC3 EPC5 Read Cycle 1 Read Cycle 2 Read Cycle 3 Read Cycle 4 Read Cycle 5 Read Cycle 6 Read Cycle 7 Client 1 Event Cycle 1 Client 2 Event Cycle 1 Client 2 Event Cycle 2 Client 3 Event Cycle 1 Report Report Report Report 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 Report Report While the diagram shows read cycles arising from a single Reader, in practice a given event cycle may collect read cycles from more than one Reader. As the diagram suggests, there may be more than one active event cycle at any point in time. Multiple active event cycles may start and end with different read cycles, and may overlap in arbitrary ways. They may gather data from the same Readers, from different Readers, or from arbitrarily overlapping sets of Readers. Multiple active event cycles could arise from one client making several simultaneous requests, or from independent clients. In all cases, however, the same read cycles are shared by all active event cycles that request data from a given Reader. The set of EPCs in a given read cycle from a given Reader is denoted by S. In the picture above, S1 = {EPC1, EPC2, EPC3} and S2 = {EPC1, EPC2, EPC4}. An event cycle is treated as a unit by clients, so clients do not see any of the internal structure of the event cycle. All that is relevant, therefore, is the complete set of EPCs occurring in any of the read cycles that make up the event cycle, from any of the Readers in the set specified for the event cycle, with duplicates removed. This is simply the union of the read cycle sets: E = S1 U S2 U …. In the example above for Client 1 Event Cycle 1 we have E1.1 = {EPC1, EPC2, EPC3, EPC4, EPC5}. Clients get information about event cycles through reports. A report is specified by a combination of these three parameters: • What set R to report, which may be • The complete set from the current event cycle R = Ecur; or Copyright © 2005, 2004 EPCglobal Inc, All Rights Reserved. Page 11 of 71
Page 1 and 2: 1 2 3 The Application Level Events
Page 3 and 4: 52 53 54 55 56 57 58 59 60 61 62 63
Page 5 and 6: 115 116 117 118 119 120 121 122 123
Page 7 and 8: 171 172 173 174 175 176 177 178 179
Page 9: 256 257 258 259 260 261 262 263 264
Page 13 and 14: 388 389 390 391 392 393 394 395 396
Page 15 and 16: 465 466 467 468 469 470 471 472 473
Page 17 and 18: 535 536 537 538 539 540 541 542 543
Page 19 and 20: 591 592 593 594 595 596 597 Once re
Page 21 and 22: 629 630 Exception Name DuplicateSub
Page 23 and 24: 657 658 659 660 661 662 663 664 665
Page 25 and 26: 731 732 733 734 735 736 737 738 739
Page 27 and 28: 800 801 802 803 804 805 806 807 808
Page 29 and 30: 865 866 867 868 869 870 871 872 873
Page 31 and 32: 903 904 905 906 907 908 909 910 911
Page 33 and 34: 964 965 966 967 968 969 970 971 972
Page 35 and 36: 1007 1008 1009 1010 1011 1012 1013
Page 37 and 38: 1078 1079 1080 1081 1082 1083 1084
Page 39 and 40: 1151 1152 1153 1154 1155 1156 1157
Page 41 and 42: 1232 1233 1234 1235 1236 1237 1238
Page 43 and 44: 1331 1332 1333 1334 1335 1336 1337
Page 45 and 46: 1471 1472 1473 1474 1475 1476 1477
Page 47 and 48: 1611 1612 1613 1614 1615 1616 1617
Page 49 and 50: 1751 1752 1753 1754 1755 1756 1757
Page 51 and 52: 1875 1876 1877 1878 1879 1880 1881
Page 53 and 54: 2015 2016 2017 2018 2019 2020 2021
Page 55 and 56: 2155 2156 2157 2158 2159 2160 2161
Page 57 and 58: 2295 2296 2297 2298 2299 2300 2301
Page 59 and 60: 2435 2436 2437 2438 2439 2440 2441
Page 61 and 62:
2575 2576 2577 2578 2579 2580 2581
Page 63 and 64:
2660 2661 2662 2663 2664 2665 2666
Page 65 and 66:
2691 2692 2693 2694 2695 2696 2697
Page 67 and 68:
2741 2742 2743 2744 2745 2746 2747
Page 69 and 70:
2780 2781 2782 2783 2784 2785 2786
Page 71:
2818 2819 2820 2821 2822 2823 2824
show all

The Application Level Events (ALE) Specification, Version 1.0 - GS1

Create successful ePaper yourself

Delete template?

Save as template?