CoRE P. van der Stok, Ed. Internet-Draft consultant Intended status: Standards Track J. Jimenez Expires: April 30, 2017 Ericsson October 27, 2016 Mapping from LWM2M model to CoMI YANG model draft-vanderstok-core-yang-lwm2m-00 Abstract This document defines a set of rules to convert a LWM2M xml-based device specification to a YANG MODULE. The invocation of the server executing the converted YANG code makes use of CoMI. The mapping from the original LWM2M URI to the corresponding CoMI URI is presented. Note Discussion and suggestions for improvement are requested, and should be sent to roll@ietf.org. Status of This Memo This Internet-Draft is submitted in full conformance with the provisions of BCP 78 and BCP 79. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF). Note that other groups may also distribute working documents as Internet-Drafts. The list of current Internet- Drafts is at http://datatracker.ietf.org/drafts/current/. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress." This Internet-Draft will expire on April 30, 2017. Copyright Notice Copyright (c) 2016 IETF Trust and the persons identified as the document authors. All rights reserved. This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents (http://trustee.ietf.org/license-info) in effect on the date of van der Stok & Jimenez Expires April 30, 2017 [Page 1] Internet-Draft LWM2M-YANG October 2016 publication of this document. Please review these documents carefully, as they describe your rights and restrictions with respect to this document. Code Components extracted from this document must include Simplified BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Simplified BSD License. Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 1.1. Terminology . . . . . . . . . . . . . . . . . . . . . . . 3 1.1.1. Tree Diagrams . . . . . . . . . . . . . . . . . . . . 3 2. Conversion rules LWM2M to YANG . . . . . . . . . . . . . . . 4 3. URI convention . . . . . . . . . . . . . . . . . . . . . . . 7 4. observation and notification . . . . . . . . . . . . . . . . 8 5. Payload format . . . . . . . . . . . . . . . . . . . . . . . 8 6. YANG extensions to LWM2M . . . . . . . . . . . . . . . . . . 8 7. Security considerations . . . . . . . . . . . . . . . . . . . 8 8. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 8 9. Changelog . . . . . . . . . . . . . . . . . . . . . . . . . . 8 10. References . . . . . . . . . . . . . . . . . . . . . . . . . 9 10.1. Normative References . . . . . . . . . . . . . . . . . . 9 10.2. Informative References . . . . . . . . . . . . . . . . . 9 Appendix A. YANG identifiers as IDnumbers . . . . . . . . . . . 10 Appendix B. YANG identifiers as resource names . . . . . . . . . 13 Appendix C. YANG identifiers as additional leaf . . . . . . . . 16 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 21 1. Introduction Standardization organizations define interfaces hosted by processors to manipulate the connected equipment. Examples of such standardization organizations are BACnet, KNX, ZigBee, oBIX, OMA/ IPSO, and many others. These organizations plan to move to resource based interfaces. The data models proposed by these organizations are hierarchical models that can be specified in XML and describe classes with attributes and operations that can be instantiated to objects. An example is the OMA LWM2M (see [OMNA]) Object model, that standardizes eight numbered object types for device management. IPSO (see [IPSO]) expands those objects to handle applications. This document describes rules to translate xml specifications of the LWM2M/IPSO organizations to YANG [RFC7950], and the invocation of the YANG based server according to the CoAP Management Interface (CoMI) specification [I-D.vanderstok-core-comi]. van der Stok & Jimenez Expires April 30, 2017 [Page 2] Internet-Draft LWM2M-YANG October 2016 1.1. Terminology The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in [RFC2119]. The following terms are defined in [RFC6241] and are not redefined here: o client o configuration data o server o state data The following terms are defined in [RFC7950] and are not redefined here: o data model o data node The terminology for describing YANG data models is found in [RFC7950]. 1.1.1. Tree Diagrams A simplified graphical representation of the data model is used in the YANG modules specified in this document. The meaning of the symbols in these diagrams is as follows: Brackets "[" and "]" enclose list keys. Abbreviations before data node names: "rw" means configuration data (read-write) and "ro" state data (read-only). Symbols after data node names: "?" means an optional node, "!" means a presence container, and "*" denotes a list and leaf-list. Parentheses enclose choice and case nodes, and case nodes are also marked with a colon (":"). Ellipsis ("...") stands for contents of subtrees that are not shown. van der Stok & Jimenez Expires April 30, 2017 [Page 3] Internet-Draft LWM2M-YANG October 2016 2. Conversion rules LWM2M to YANG LWM2M objects are typed, where each type is identified with a number. The object provides one or more instances which are numbered. An instance is composed of resources, also identified with numbers. An instance on a host can be accessed with the example URI: coap+lwm2m://example.com/object/instance/resource, where resource, instance and object are numbers, specified by the LWM2M specification. When using YANG, the object identifiers, followed by the resource identifier, are YANG strings instead of numbers. The format of the instance identifier depends on the YANG model that is chosen to specify LWM2M objects. For an automatic translation from the XML LWM2M specification to a YANG specification, the following rules apply for access, optional, units, and range specifications: o The optional/mandatory aspect of the LWM2M resource is covered by the leaf's mandatory "false/true" statement of YANG as specified in section 7.6.5 of [RFC7950]. The YANG statement "mandatory = TRUE" means that(given the right conditions) the leaf must exist. o The R,W access aspects of a data item are translated using the YANG "config" statement as specified in section 7.21.1 of [RFC7950]. If "config" is "true", the Data nodes are part of configuration datastores, resulting in RW access. If "config" is "false", the data nodes are not part of configuration datastores, resulting in R access. YANG does not provide facilities to specify W access only. o When the YANG RPC is specified, E access is meant. In section 7.14 of [RFC7950] RPCs are modelled for NETCONF using YANG input and output parameters. When input parameters are added, EW access is meant; when output parameters are added, ER access is meant and with both input and output parameters ERW access is meant. o The YANG ACTION is specified in section 7.15 of [RFC7950]. Contrary to RPC, ACTION statement is associated with a data node. The data node has E access. Input leafs of the data node have W access, and output leafs have R access. o To specify the range of a data resource the YANG range statement, specified in section 9.2.4 of [RFC7950], is used. o YANG range can be used in a straightforward fashion for items of type integer. The range of decimal64, used for float, is less van der Stok & Jimenez Expires April 30, 2017 [Page 4] Internet-Draft LWM2M-YANG October 2016 straightforward. The possible ranges are restricted by the fraction-digits which specifies the size of the fraction part of the float (see section 9.3.4. of [RFC7950]. o The YANG units statement, specified in section 7.3.3 of [RFC7950], is used to express the units. o The attributes of the YANG leaf need to be presented in the order: "type", possibly qualified with "range", "units", "config", "mandatory", and finally "Description". o In the presented YANG specification the LWM2M resources are specified as leafs of a YANG list. YANG lists may contain key leafs which uniquely identify an instance in a list. By specifying a key leaf (for example called "instance") that contains the list instance number, the YANG list instance can be uniquely referenced by the instance number. Accordingly, OMA objects are modelled as YANG lists. The value of the "instance" leaf in the list is equal to the instance number of the OMA object. The numbering of the instances does not need to be consecutive. The OMA resources are the other leafs of the YANG list. Choices need to be made how to represent the numbered object ID, and resource ID as YANG identifiers. YANG identifiers are strings and cannot be represented by numbers. The YANG identifier strings need to be mapped to numbered identifiers. The appendices show 3 ways to represent the LWM2M device ID and resource ID in the YANG specification. o In Appendix A, Yang Identifiers are modelled as strings that start with string "ID" followed by the identifier number (see module humidityID). o In Appendix B, Yang Identifiers of objects and resources are modelled as strings that are equivalent to the OMA object- and resource- name (see module humidityNM). o In Appendix C, the OMA device is modelled as a YANG container composed of an identifier and a list of instances. The list is composed of an instance number and a set of resource containers. The resource container is composed of the pair (attribute identifier number, IPSO resource specification)(see module humidityLF). Below the tree diagrams (see Section 1.1.1 for an explanation of the syntax) of the three valid YANG modules are shown. van der Stok & Jimenez Expires April 30, 2017 [Page 5] Internet-Draft LWM2M-YANG October 2016 module: ietf-yang-humidityID +--ro ID3304* [instance] +--ro instance uint16 +--ro ID5700 decimal64 +--ro ID5701? string +--ro ID5601? decimal64 +--ro ID5602? decimal64 +--ro ID5603? decimal64 +--ro ID5604? decimal64 +---x ID5605 module: ietf-yang-humidityNM +--ro IPSO-humidity* [instance] +--ro instance uint16 +--ro Sensor_Value decimal64 +--ro Units? string +--ro Min_Measured_Value? decimal64 +--ro Max_Measured_Value? decimal64 +--ro Min_Range_Value? decimal64 +--ro Max_Range_Value? decimal64 +---x Reset_Min_and_Max_measured_values module: ietf-yang-humidityLF +--rw IPSO-humidity +--ro identifier uint16 +--ro resources* [instance] +--ro instance uint16 +--ro Sensor_Value | +--ro identifier? uint16 | +--ro content decimal64 +--ro Units | +--ro identifier? uint16 | +--ro content? string +--ro Min_Measured_Value | +--ro identifier? uint16 | +--ro content? decimal64 +--ro Max_Measured_Value | +--ro identifier? uint16 | +--ro content? decimal64 +--ro Min_Range_Value | +--ro identifier? uint16 | +--ro content? decimal64 +--ro Max_Range_Value | +--ro identifier? uint16 | +--ro content? decimal64 +--ro Reset_Min_and_Max_measured_values +--ro identifier? uint16 van der Stok & Jimenez Expires April 30, 2017 [Page 6] Internet-Draft LWM2M-YANG October 2016 +---x reset Module humidityLF of Appendix C is the most complex one and is not recommended. Module humidityID of Appendix A works but is a bit forced approach and lacks the resource name. Module humidityNM of Appendix B is the most natural approach where the YANG identifiers are equal to the device (type) and resource names. CoMI [I-D.vanderstok-core-comi] uses a conversion from names to numbers to reduce the request URI size, and the payload of the server requests and answers. The LWM2M organization specifies both the names and the numbers of the devices and resources. The number of the resource is not unique and for the CoMI identifier the resource number needs to be prefixed by the device number to be unique. 3. URI convention The invocation URI of a LWM2M resource looks like: coap+lwm2M://example.com/object/instance/resource In this section it is assumed that the YANG mapping of the module humidityNM of Appendix B is used. When YANG is used, the LWM2M resource invocation can follow the RESTCONF convention using http, or the CoMI convention using CoAP. When using RESTCONF (see section 3.5.3 of [I-D.ietf-netconf-restconf] the invocation of object with instance = number will look like: http://example.com/object/instance=number/resource In the case of CoMI the object/resource numbers are used, and not the names, to reduce the payload size. The instance is specified in a query parameter. Consequently, the LWM2M resource on a server executing a YANG specification, is accessed according to the CoMI specification with: coap://example.com/identifier?k=number The identifier is a composition of the object number and the resource number. Assume that n is smallest number for which 10**(n+1)/resource >= 1. The value of the identifier = (object*10**n)+resource. Assume that the IPSO-humidity/Sensor_Value 3304/5700 numbers are composed to the numeric identifier 33045700. According to [RFC4648], van der Stok & Jimenez Expires April 30, 2017 [Page 7] Internet-Draft LWM2M-YANG October 2016 the identifier is represented in base64 which leads to B-DzE. The URI for the CoMI invocation of instance 0 of IPSO-humidity/ Sensor_value will look like: coap://example.com/B-DzE?k=0 For LWM2M objects with only one instance, the k=0 can be omitted. 4. observation and notification An LWM2M server uses "observe" to receive notification from the server. This remains unchanged with YANG servers and CoMI. 5. Payload format The payload of the request and the response follows the payload format specified for CoMI. The content format is CBOR [RFC7049]. The YANG objects are returned as maps containing (identifier, value) pairs. Where the identifier is the numeric identifier discussed in Section 3. and the value is of the type specified by the YANG specification of the server. The CBOR encoding of the YANG types is specified in [I-D.ietf-core-yang-cbor]. 6. YANG extensions to LWM2M By adding keys leafs to a list object, YANG allows additionally the selection of instances by the contents of the key leafs. The FETCH method of CoAP makes it possible to request multiple resource instances in one request. The notification statement of YANG encourages a more flexible specification of notifications. 7. Security considerations To be filled in 8. Acknowledgements We are grateful to 9. Changelog NO changes from nothing to version 00 van der Stok & Jimenez Expires April 30, 2017 [Page 8] Internet-Draft LWM2M-YANG October 2016 10. References 10.1. Normative References [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, March 1997, . [RFC7950] Bjorklund, M., Ed., "The YANG 1.1 Data Modeling Language", RFC 7950, DOI 10.17487/RFC7950, August 2016, . [RFC6241] Enns, R., Ed., Bjorklund, M., Ed., Schoenwaelder, J., Ed., and A. Bierman, Ed., "Network Configuration Protocol (NETCONF)", RFC 6241, DOI 10.17487/RFC6241, June 2011, . [RFC4648] Josefsson, S., "The Base16, Base32, and Base64 Data Encodings", RFC 4648, DOI 10.17487/RFC4648, October 2006, . [RFC7049] Bormann, C. and P. Hoffman, "Concise Binary Object Representation (CBOR)", RFC 7049, DOI 10.17487/RFC7049, October 2013, . [I-D.vanderstok-core-comi] Stok, P. and A. Bierman, "CoAP Management Interface", draft-vanderstok-core-comi-09 (work in progress), March 2016. [I-D.ietf-core-yang-cbor] Veillette, M., Pelov, A., Somaraju, A., Turner, R., and A. Minaburo, "CBOR Encoding of Data Modeled with YANG", draft-ietf-core-yang-cbor-02 (work in progress), July 2016. 10.2. Informative References [I-D.ietf-netconf-restconf] Bierman, A., Bjorklund, M., and K. Watsen, "RESTCONF Protocol", draft-ietf-netconf-restconf-17 (work in progress), September 2016. [OMNA] "Open Mobile Naming Authority (OMNA)", Web http://http://technical.openmobilealliance.org/Technical/ technical-information/omna. van der Stok & Jimenez Expires April 30, 2017 [Page 9] Internet-Draft LWM2M-YANG October 2016 [IPSO] "IP for Smart Objects (IPSO)", Web http://ipso-alliance.github.io/pub/. Appendix A. YANG identifiers as IDnumbers Yang Identifiers are modelled as string that starts with ID followed by the identifier number. The device object is modelled as a list that contains multiple instances. file "ietf-humidityID@2016-07-25.yang" module ietf-humidityID{ yang-version 1.1; // needed for action namespace "urn:ietf:params:xml:ns:yang:ietf-humidityID"; prefix humid; organization "IPSO"; contact "WG Web: http://tools.ietf.org/wg/core/ WG List: mailto:core@ietf.org WG Chair: Carsten Bormann mailto:cabo@tzi.org WG Chair: Jaime Jimenez mailto:jaime.jimenez@ericsson.com Editor: Peter van der Stok mailto:consultancy@vanderstok.org Editor: Jaime Jimenez mailto:jaime.jimenez@ericsson.com"; description "This module contains information about the operation of the IPSO LWM2M humidity sensor with ID 3304. Copyright (c) 2016 IETF Trust and the persons identified as authors of the code. All rights reserved. Redistribution and use in source and binary forms, with or without modification, is permitted pursuant to, and subject to the license terms contained in, the Simplified BSD License van der Stok & Jimenez Expires April 30, 2017 [Page 10] Internet-Draft LWM2M-YANG October 2016 set forth in Section 4.c of the IETF Trust's Legal Provisions Relating to IETF Documents (http://trustee.ietf.org/license-info). This version of this YANG module is part of RFC XXXX; see the RFC itself for full legal notices."; revision "2016-07-25" { description "Initial revision."; reference "I-D:draft-vanderstok-core-yang-lwm2m: YANG language applied to the LWM2M IPSO humidity sensor specification"; } list ID3304 { key instance; config false; // should be same for key leaf description "IPSO humidity: The humidity sensor is composed of a set of instances"; leaf instance { type uint16{ range "0..1"; // only one instance zero (0) } config false; // R access mandatory "true"; description "the number of the humidity sensor instance"; } leaf ID5700 { type decimal64{ // YANG has no float fraction-digits 2; range "10.0 .. 66.6";} config false; // R access mandatory "true"; description "Sensor Value: Last or Current Measured Value from the Sensor"; } leaf ID5701 { type string; units "Defined by 'Units' resource"; config false; // R access description "Units: Measurement unit definition e.g. 'Cel' for temperature in Celsius"; } leaf ID5601 { van der Stok & Jimenez Expires April 30, 2017 [Page 11] Internet-Draft LWM2M-YANG October 2016 type decimal64{ // YANG has no float fraction-digits 2; range "10.0 .. 66.6";} units "Defined by 'Units' resource"; config false; // R access description "Min Measured Value: The minimum value measured by the sensor since power ON or reset"; } leaf ID5602 { type decimal64{ // YANG has no float fraction-digits 2; range "10.0 .. 66.6";} units "Defined by 'Units' resource"; config false; // R access description "Max Measured Value: The maximum value measured by the sensor since power ON or reset"; } leaf ID5603 { type decimal64{ // YANG has no float fraction-digits 2; range "10.0 .. 66.6";} units "Defined by 'Units' resource"; config false; // R access description "Min Range Value: The minimum value that can be measured by the sensor"; } leaf ID5604 { type decimal64{ // YANG has no float fraction-digits 2; range "10.0 .. 66.6";} units "Defined by 'Units' resource"; config false; // R access description "Max Range Value: The maximum value that can be measured by the sensor"; } action ID5605 { //E access: this is an RPC // without input and output parameters description "Reset Min and Max measured values: Reset the Min and Max measured values to current value"; } } // list ID3304 } // module ietf-yang-humidity van der Stok & Jimenez Expires April 30, 2017 [Page 12] Internet-Draft LWM2M-YANG October 2016 Appendix B. YANG identifiers as resource names Yang Identifiers are modelled as strings that represent the resource name. The device object is modelled as a list with multiple instances. file "ietf-humidityNM@2016-07-25.yang" module ietf-humidityNM{ yang-version 1.1; // needed for action namespace "urn:ietf:params:xml:ns:yang:ietf-humidityNM"; prefix humid; organization "IPSO"; contact "WG Web: http://tools.ietf.org/wg/core/ WG List: mailto:core@ietf.org WG Chair: Carsten Bormann mailto:cabo@tzi.org WG Chair: Jaime Jimenez mailto:jaime.jimenez@ericsson.com Editor: Peter van der Stok mailto:consultancy@vanderstok.org Editor: Jaime Jimenez mailto:jaime.jimenez@ericsson.com"; description "This module contains information about the operation of the IPSO LWM2M humidity sensor with ID 3304. Copyright (c) 2016 IETF Trust and the persons identified as authors of the code. All rights reserved. Redistribution and use in source and binary forms, with or without modification, is permitted pursuant to, and subject van der Stok & Jimenez Expires April 30, 2017 [Page 13] Internet-Draft LWM2M-YANG October 2016 to the license terms contained in, the Simplified BSD License set forth in Section 4.c of the IETF Trust's Legal Provisions Relating to IETF Documents (http://trustee.ietf.org/license-info). This version of this YANG module is part of RFC XXXX; see the RFC itself for full legal notices."; revision "2016-07-25" { description "Initial revision."; reference "I-D:draft-vanderstok-core-yang-lwm2m: YANG language applied to the LWM2M IPSO humidity sensor specification"; } list IPSO-humidity { key instance; config false; // should be same as key leaf description "3304: The humidity sensor is composed of a set of instances"; leaf instance { type uint16{ range "0..1"; // only one instance zero (0) } config false; // R access mandatory "true"; description "the number of the humidity sensor instance"; } leaf Sensor_Value { type decimal64{ // YANG has no float fraction-digits 2; range "10.0 .. 66.6";} units "Defined by 'Units' resource"; config false; // R access mandatory "true"; description "5700: Last or Current Measured Value from the Sensor"; } leaf Units { type string; units "Defined by 'Units' resource"; config false; // R access description van der Stok & Jimenez Expires April 30, 2017 [Page 14] Internet-Draft LWM2M-YANG October 2016 "5701: Measurement unit definition e.g. 'Cel' for temperature in Celsius"; } leaf Min_Measured_Value { type decimal64{ // YANG has no float fraction-digits 2; range "10.0 .. 66.6";} units "Defined by 'Units' resource"; config false; // R access description "5601: The minimum value measured by the sensor since power ON or reset"; } leaf Max_Measured_Value { type decimal64{ // YANG has no float fraction-digits 2; range "10.0 .. 66.6";} units "Defined by 'Units' resource"; config false; // R access description "5602: The maximum value measured by the sensor since power ON or reset"; } leaf Min_Range_Value { type decimal64{ // YANG has no float fraction-digits 2; range "10.0 .. 66.6";} units "Defined by 'Units' resource"; config false; // R access description "5603: The minimum value that can be measured by the sensor"; } leaf Max_Range_Value{ type decimal64{ // YANG has no float fraction-digits 2; range "10.0 .. 66.6";} units "Defined by 'Units' resource"; config false; // R access description "5604: The maximum value that can be measured by the sensor"; } action Reset_Min_and_Max_measured_values { // E access: this is an RPC // without input and output parameter description "5605: Reset the Min and Max measured values van der Stok & Jimenez Expires April 30, 2017 [Page 15] Internet-Draft LWM2M-YANG October 2016 to current value"; } // rpc } // list ID3304 } // module ietf-yang-humidity Appendix C. YANG identifiers as additional leaf The device object is modelled as a container composed of an identifier and a list of instances. The list instance is composed of an instance number and a set of resource containers. The resource container is composed of the pair (attribute identifier number, IPSO resource specification). file "ietf-humidityLF@2016-07-25.yang" module ietf-humidityLF{ yang-version 1.1; // needed for rpc namespace "urn:ietf:params:xml:ns:yang:ietf-humidityLF"; prefix humid; organization "IPSO"; contact "WG Web: http://tools.ietf.org/wg/core/ WG List: mailto:core@ietf.org WG Chair: Carsten Bormann mailto:cabo@tzi.org WG Chair: Jaime Jimenez mailto:jaime.jimenez@ericsson.com Editor: Peter van der Stok mailto:consultancy@vanderstok.org Editor: Jaime Jimenez mailto:jaime.jimenez@ericsson.com"; van der Stok & Jimenez Expires April 30, 2017 [Page 16] Internet-Draft LWM2M-YANG October 2016 description "This module contains information about the operation of the IPSO LWM2M humidity sensor with ID 3304. Copyright (c) 2016 IETF Trust and the persons identified as authors of the code. All rights reserved. Redistribution and use in source and binary forms, with or without modification, is permitted pursuant to, and subject to the license terms contained in, the Simplified BSD License set forth in Section 4.c of the IETF Trust's Legal Provisions Relating to IETF Documents (http://trustee.ietf.org/license-info). This version of this YANG module is part of RFC XXXX; see the RFC itself for full legal notices."; revision "2016-07-25" { description "Initial revision."; reference "I-D:draft-vanderstok-core-yang-lwm2m: YANG language applied to the LWM2M IPSO humidity sensor specification"; } container IPSO-humidity{ description "Device separated in identifier and list"; leaf identifier{ type uint16; // fixed to 3304 config false; mandatory "true"; description "the LWM2M identification number of the device"; } list resources { key instance; config false; // should be same as key leaf description "3304: The humidity sensor is composed of a set of instances"; leaf instance { type uint16{ range "0..1"; // only one instance zero (0) } config false; // R access mandatory "true"; description van der Stok & Jimenez Expires April 30, 2017 [Page 17] Internet-Draft LWM2M-YANG October 2016 "the number of the humidity sensor instance"; } // instance number container Sensor_Value { description "Resource separated in identifier and content"; leaf identifier{ type uint16; // fixed to 5700 config false; // R access description "identifier should contain the value 5700"; } leaf content{ type decimal64{ // YANG has no float fraction-digits 2; range "10.0 .. 66.6";} units "Defined by 'Units' resource"; config false; // R access mandatory "true"; description "5700: Last or Current Measured Value from the Sensor"; } // content } // container container Units { description "Resource separated in identifier and content"; leaf identifier{ type uint16; // fixed to 5701 config false; // R access description "identifier should contain the value 5701"; } leaf content{ type string; units "Defined by 'Units' resource"; config false; // R access description "5701: Measurement unit definition e.g. 'Cel' for temperature in Celsius"; } // content } // container container Min_Measured_Value { description "Resource separated in identifier and content"; leaf identifier{ type uint16; // fixed to 5601 config false; // R access description van der Stok & Jimenez Expires April 30, 2017 [Page 18] Internet-Draft LWM2M-YANG October 2016 "identifier should contain the value 5601"; } // identifier leaf content{ type decimal64{ // YANG has no float fraction-digits 2; range "10.0 .. 66.6";} units "Defined by 'Units' resource"; config false; // R access description "5601: The minimum value measured by the sensor since power ON or reset"; } // content } container Max_Measured_Value { description "Resource separated in identifier and content"; leaf identifier{ type uint16; // fixed to 5602 config false; // R access description "identifier should contain the value 5602"; } leaf content{ type decimal64{ // YANG has no float fraction-digits 2; range "10.0 .. 66.6";} units "Defined by 'Units' resource"; config false; // R access description "5602: The maximum value measured by the sensor since power ON or reset"; } // content } // container container Min_Range_Value { description "Resource separated in identifier and content"; leaf identifier{ type uint16; // fixed to 5603 config false; // R access description "identifier should contain the value 5603"; } // identifier leaf content{ type decimal64{ // YANG has no float fraction-digits 2; range "10.0 .. 66.6";} units "Defined by 'Units' resource"; config false; // R access van der Stok & Jimenez Expires April 30, 2017 [Page 19] Internet-Draft LWM2M-YANG October 2016 description "5603: The minimum value that can be measured by the sensor"; } // content } // container container Max_Range_Value{ description "Resource separated in identifier and content"; leaf identifier{ type uint16; // fixed to 5604 config false; // R access description "identifier should contain the value 5604"; } // identifier leaf content{ type decimal64{ // YANG has no float fraction-digits 2; range "10.0 .. 66.6";} units "Defined by 'Units' resource"; config false; // R access description "5604: The maximum value that can be measured by the sensor"; } // content } container Reset_Min_and_Max_measured_values { description "Resource separated in identifier and action"; leaf identifier{ type uint16; // fixed to 5605 config false; // R access description "identifier should contain the value 5605"; } action reset{ // E access: this is an RPC without input and output parameters description "5605: Reset the Min and Max measured values to current value"; } // action reset } // container Reset_min_and_max } // list resources } // container IPSO-humidity (3304) } // module ietf-yang-humidity van der Stok & Jimenez Expires April 30, 2017 [Page 20] Internet-Draft LWM2M-YANG October 2016 Authors' Addresses Peter van der Stok (editor) consultant Phone: +31-492474673 (Netherlands), +33-966015248 (France) Email: consultancy@vanderstok.org URI: www.vanderstok.org Jaime Jimenez Ericsson Hirsalantie 11 Jorvas 02420 Finland Phone: +358-442992827(Finland) Email: jaime.jimenez@ericsson.com van der Stok & Jimenez Expires April 30, 2017 [Page 21]