ANSI Std C1223 Trilliant.doc

1 ansi std c12 23 200 x compliance testing for standard protocol c12 18 copyright 200x by the national electrical manufacturers association 1300 north 17th street suite 1847 rosslyn va 22209 usa all rights reserved this is an unapproved draft of a proposed ansi standard subject to change permission is hereby granted for ansi standards committee participants to reproduce this document for purposes of ansi standardization activities use of information contained in this unapproved draft is at your own risk modified october 20 2005 standard version 0 0 document version 1 0 2 table of contents 1 introduction 4 2 scope 4 3 document syntax 4 4 references 4 5 definitions 4 5 1 psem 4 5 2 table 4 5 2 1 ansi 5 5 2 2 application layer 5 5 2 3 amr 5 5 2 4 baud rate 5 5 2 5 catastrophic failure a k a fatal failure 5 5 2 6 crc 5 5 2 7 data link layer 5 5 2 8 device under test 5 5 2 9 dut 5 5 2 10 flc 5 5 2 11 function under test 6 5 2 12 fut 6 5 2 13 half duplex 6 5 2 14 meter under test 6 5 2 15 mut 6 5 2 16 octet 6 5 2 17 packet 6 5 2 18 packet envelope 6 5 2 19 psem 6 5 2 20 retrieve 6 5 2 21 test 7 5 2 22 test application 7 5 2 23 write 7 6 product submission and verification criteria 7 6 1 rational 7 6 2 submission rules 7 6 3 verification goals 7 6 4 verification non goals 8 6 5 interpretation of the standards 8 6 6 other criteria 8 6 6 1 example 1 8 6 6 2 example 2 9 6 6 3 example 3 9 6 6 4 example 4 10 7 general conformance statement 10 7 1 the test application 10 7 2 the test application as a reference ansi c12 19 ieee 1377 implementation 11 7 3 test results and ranking categories 11 7 3 1 not applicable 11 3 7 3 2 not tested 11 7 3 3 conforming 11 7 3 4 conforming with discrepancy 11 7 3 5 non conforming 11 7 3 6 non conforming rejected 12 7 3 7 test remarks 12 8 verification objectives for ansi c12 18 devices 12 8 1 ansi standard c12 19 1997 ieee 1377 utility industry standard tables 12 8 1 1 type of tables 12 8 1 2 operations on tables 12 8 2 ansi standard c12 18 1996 protocol specification for ansi type 2 optical port 13 8 2 1 basic implementation assumptions 13 8 2 2 states and services 13 9 test procedures for ansi c12 18 14 9 1 test procedures for the physical layer 14 9 1 1 transmitter characteristics section 4 8 3 2 14 9 2 test procedures for the data link layer 15 9 2 1 pre test general set up requirements 15 9 2 2 basic sanity check 16 9 2 3 immunity to random noise 16 9 2 4 ack returned due to reception of a duplicate packet 17 9 2 5 nak returned due to crc error 17 9 2 6 nak returned due to inter character timeout 17 9 2 7 nak returned due to long packet 18 9 2 8 nak returned due to invalid multi packet flag setting 19 9 2 9 nak returned due to invalid first packet flag setting 19 9 2 10 nak returned due to an invalid sequence number 19 9 2 11 retransmission triggered by a response timeout 20 9 2 12 retransmission triggered by a nak 20 9 2 13 link termination after third retry attempt nak 21 9 2 14 link termination after third retry attempt response timeout 21 9 2 15 link termination due to channel traffic timeout 22 9 2 16 sensitivity to the initial state of the toggle bit 23 9 2 17 default packet size validation read 23 9 2 18 default packet size validation write 24 9 3 psem test procedures 24 9 3 1 psem service transaction 24 9 3 2 identification service response 25 9 3 3 negotiate service change baud rate 25 9 3 4 negotiate service number of packets and packet size 26 9 3 5 negotiate service honors negotiated limits 26 9 3 6 negotiate service establish maximum packet limits 27 9 3 7 wait service 28 9 3 8 terminate service working 28 9 3 9 service sequence state 29 annex a test reports normative 30 a 1 tests summary sheet 30 a 2 detail results of test procedures for ansi standard c12 18 1996 31 a 2 1 results of test procedures for the data link layer 31 a 2 2 results of psem test procedures 31 annex b verification codes normative 31 4 to do create a requirement metrix and qualify each test base on this metrix to do add examples of real message format to do format the definitions section todo add list test equipment and traceability to standards 1 introduction give some background about this standard what it has to accomplish the referenced standard and how its envisioned to be implemented in the industry add text on pre requisites and order of tests 2 scope this document is a collection of compliance test procedures that aim to validate the implementation correctness of ansi c12 19 1997 ieee 1377 devices that communicate using ansi c12 18 1996 standard communication 3 document syntax explain the various annotations used in this document 4 references ansi std c12 18 1996 protocol specification for ansi type 2 optical port iso 7498 1 osi reference model iso 3309 1993 e information technology telecommunications and information exchange between systems high level data link control hdlc procedures frame structure annex a explanatory notes on implementation of the frame checking sequence ansi std c12 19 1997 utility industry end device data tables 5 definitions for the purposes of this document the following definitions are made for terms and syntax used throughout this document 5 1 psem protocol specification for electricity metering as referenced in c12 18 1996 5 2 table functionally related data elements grouped together into a single data structure for transport as defined by ansi standard c12 19 1997 5 5 2 1 ansi american national standards institute the primary organization for fostering the development of technology standards in the united states ansi works with industry groups and is the u s member of the international standards organization iso and the international electrotechnical commission iec 5 2 2 application layer the application layer osi layer 7 is the layer at which a user application interfaces with a communication network 5 2 3 amr amr is an acronym for automated meter reading 5 2 4 baud rate baud was the prevalent measure for data transmission speed until replaced by a more accurate term bps bits per second one baud is one electronic state change per second since a single state change can involve more than a single bit of data the bps unit of measurement has replaced it as a better expression of data transmission speed the standards use the terms baud baud rate bps and bits per second interchangeably 5 2 5 catastrophic failure a k a fatal failure a failure that results in temporary or permanent disruption of communication corruption of protocol delivery of wrong data misrepresentation of data format incorrect placement of data in accordance to the test application reference model 5 2 6 crc crc is an acronym for cyclic redundancy check the crc is used to validate the integrity of the transmitted packets 5 2 7 data link layer the data link layer osi layer 2 provides the synchronization of data error detection and correction procedures used during data transmission 5 2 8 device under test a c12 19 utility industry standard tables driven device using c12 18 c12 21 or optionally c12 22 in any combination this device and its accessories are being tested for successful communication and data exchange with test application the tests are carried in a sequence one function under test at a time 5 2 9 dut dut is an acronym for device under test 5 2 10 flc ansi c12 19 ieee 1377 function limiting control tables x0 x1 where x is the decade number 0 240 6 5 2 11 function under test a software firmware hardware or protocol component test that is applied to a device under test in order to validate the correct performance of a component the test will establish whether the component meets or does not meet interface state timing data values data representation data placement protocol or implementation requirements in reference to the test application a conforming conforming with discrepancy non conforming or non conforming rejected grade shall be assigned following the test of each function under test 5 2 12 fut fut is an acronym for function under test 5 2 13 half duplex half duplex data transmission means that data can be transmitted in both directions on a signal carrier but not at the same time one station can send data on the line and then shortly after receive data on the line from the same direction in which data was just transmitted 5 2 14 meter under test a device under test that is a sensor measuring water gas or electricity 5 2 15 mut mut is an acronym for meter under test 5 2 16 octet an octet from the latin octo or eight is a sequence of eight bits an octet is an eight bit byte 5 2 17 packet a packet is the unit of data that is routed between an origin and a destination in an ansi c12 18 dut the individual packets may be fragments of a given service request when they have all arrived they are reassembled into the original message at the receiving end an ansi c12 18 packet begins with the start of packet octet 0 xee and ends with a two octets crc based on the ccitt crc standard polynomial x16 x12 x5 1 5 2 18 packet envelope the packet s start of packet octet and the end of packet crc 5 2 19 psem psem is an acronym for protocol specification for electric metering usa psem is an acronym for protocol specification for electronic metering canada 5 2 20 retrieve to cause the transmission from the dut to the test application of an entire or partial dut table the act of data retrieval may require the invocation of some or all the following psem services identification negotiate logon wait security read and logoff 7 5 2 21 test a test is the execution of one element of a fut procedure by the test application 5 2 22 test application the test application is a software application built to enable manufacturers utilities and meter verifiers to migrate their amr and testing environment to ansi c12 19 standard based technology it can read and program any ansi c12 19 based device that uses ansi c12 18 standard communication protocol it also accepts and creates table definition files which describe the architecture and state of any ansi c12 19 device it may also be a diagnostic and test tool which is a reference application used to validate device design assumptions and implementation details 5 2 23 write to cause the transmission from the test application to dut of an entire or partial dut table the act of data writing may in addition to the above require the invocation of some or all the following psem services identification negotiate logon wait security read write and logoff the dut may require the invocation of the procedure 2 save configuration prior to logoff for it to retain the changes 6 product submission and verification criteria 6 1 rational this document defines a suite of tests with well defined acceptance criteria that promotes interoperability among devices that use the referenced standards 6 2 submission rules it shall be required to obtain manufacturer consent to each compliance procedure for the fut test procedures that do not meet with manufacturer approval or are withdrawn by the manufacturer prior to test initiation shall be entered as not tested and an explanation for the result shall be entered in the exception field of the report the test suite outlined in this document performs an assessment of the dut and its ability to conform to the said reference test application the following is a summary of the general components that will and will not be assessed as part of these conformance tests 6 3 verification goals the tester shall perform an assessment of the following 1 completeness of submission of dut for testing e g meter connectors accessories manuals supporting electronic files etc 2 configuration and state disclosure of the dut prior to testing passwords special processes jumper settings mode settings etc 3 readiness of the dut for testing e g is it in metering state is it sealed does it need to be set up if so how 4 compatibility with test application communication reference interface c12 18 at the physical layer 5 compatibility with test application communication reference implementation c12 18 at the data link layer 8 6 compatibility with test application protocol reference implementation c12 18 at the application layer psem 7 general assessment of firmware stability solely derived from performing the tests describes above 6 4 verification non goals the tester shall not perform an assessment of the following 1 dut accuracy tests including time interval and metrological registers 2 dut reliability tests drop test vibration test electromagnetic susceptibility weather temperature etc 3 hardware interface quality accuracy and signaling strengths except where it clearly does not work reliably 4 device factory configuration and setup 5 implementation logic assessment of device functions implemented their delivery logic or value to customer 6 evaluation of device performance efficiency and effective delivery of advertised functionality to the marketplace 6 5 interpretation of the standards explain how this standard is applied and how other standards are interpreted explain how ambiguity is addressed or not addresses give an example 6 6 other criteria 1 where the standard is clear and unambiguous produce a clear pass fail a result 2 where the standard is unambiguously clear in its intent but does not provide implementation details for the required functionality apply common sense 3 where the standard is vague or there is room for multiple interpretations the test will be written to handle the alternatives and expose the variations 4 where the standard says nothing or is so vague that one cannot formulate a test do not test do we want to revise these examples to be specific to c12 18 6 6 1 example 1 this example describes a test result where the standard is clear and unambiguous description event inhibit ovf flag is defined as follows in table 71 falseevent log is not inhibiting new entries when an overflow condition exists trueevent log is inhibiting new entries when an overflow condition exists overflow flag is defined as follows in table 76 falseoverflow has not occurred 9 truean attempt was made to enter an event such that the number of unread entries would have exceeded the actual number of possible entries in the log conclusion the standard is very clear in its expression of the intended implementation of the overflow flag status as restricted by the event inhibit ovf flag control flag therefore one cannot argue against a test that validates the behavior of an end device following excessive excitation that will cause the log to overflow the compliant log shall not overflow if event inhibit ovf flag control flag is true and it shall overflow if event inhibit ovf flag control flag is false regardless of the state of event inhibit ovf flag control flag the overflow flag shall be set 6 6 2 example 2 this example describes a test result where the standard is unambiguously clear in its intent but does not provide implementation details for the intent description list type flag is defined as follows in table 26 falsefifo first in first out as placed in self read list truecircular list as placed in self read list list type is defined as follows in table 63 0fifo first in first out as placed in load profile storage 1circular list as placed in load profile storage list type is defined as follows in table 74 0fifo as placed in log 1circular as placed in log conclusion the acronym fifo is not defined in the standard however the standard qualifies the term fifo in table 26 and table 63 with the definition first in first out using flawed logic one can argue that one cannot make any assumption about what the term fifo means in table 74 since the standard is silent about that this follows the reasoning similar to that of manufacturer tables do not have flcs so what would one make out of fifo in table 74 does fifo mean first in first out or fill in faulty order or first in final out one could argue that a test for fifo in table 74 cannot be carried out on this basis reasonable people would say that it is rather obvious that based on prior use of the term fifo the standard is clear about the intended use of the definition first in first out and the compliance standard shall perform the tests accordingly caveat the term circular is not defined in the standard does it mean that c12 23 cannot have a test for circular vs fifo since we do not know what it really means in terms of placement or ordering of entries in a logs if so how can one build an amr system to read a log based on the c12 19 standard 6 6 3 example 3 this example describes a test where the standard is vague or there is room for possibilities the test will be written to cope with these possibilities and expose the variations description 10 the value of the element last entry seq nbr 0 4 294 967 295 the sequence number of the newest valid entry in the log is not clearly described by c12 19 it could retain its value after a reset list pointers or it could be reset however there are only two possible outcomes following the execution of a reset list pointers procedure last entry seq nbr retains its value last entry seq nbr does not retain its value conclusion the standard is clear that following execution of a reset list pointer procedure all elements that describe the content extent of the list shall be consistent with that of the empty list therefore one can design a test that validates the reset action to create an empty list and also report the value of last entry seq nbr before and after the test this will expose the actual implementation model of the dut implementation variations of the last entry seq nbr shall not result in a failure of a dut unless there is a country specific clause regarding a specific desired behavior e g for canada 6 6 4 example 4 this example describes a test where the standard says nothing and it is so vague that one cannot formulate a test description event log ctrl tbl table 75 defines the event log codes to be written to the event log it also define