ISO 20242-2:2010

INTERNATIONAL ISO
STANDARD 20242-2
First edition
2010-09-01

Industrial automation systems and
integration — Service interface for testing
applications —
Part 2:
Resource management service interface
Systèmes d'automatisation industrielle et intégration — Interface de
service pour contrôler les applications —
Partie 2: Interface de service pour la gestion de ressource




Reference number
ISO 20242-2:2010(E)
©
ISO 2010

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ISO 20242-2:2010(E)
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ISO 20242-2:2010(E)
Contents Page
Foreword .iv
Introduction.v
1 Scope.1
2 Normative references.1
3 Terms and definitions .1
4 Symbols and abbreviated terms .1
5 Conventions for service definitions and procedures .2
5.1 General .2
5.2 Parameters .2
5.3 Service procedures .3
5.4 Service primitives and state diagrams.3
6 Resource Management Services .4
6.1 Overview.4
6.2 List of services .5
6.3 Management support services.7
6.4 Input/output services .11
6.5 Extended services.28
6.6 Operating Support Services.32
6.7 States of RMS state machine .60
Annex A (informative) Implementation guidelines for RMSI — Mapping of services to C/C++
function calls .64
Annex B (informative) Cascading of device drivers via RMSI.77
Bibliography.79

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ISO 20242-2:2010(E)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies
(ISO member bodies). The work of preparing International Standards is normally carried out through ISO
technical committees. Each member body interested in a subject for which a technical committee has been
established has the right to be represented on that committee. International organizations, governmental and
non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the
International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
The main task of technical committees is to prepare International Standards. Draft International Standards
adopted by the technical committees are circulated to the member bodies for voting. Publication as an
International Standard requires approval by at least 75 % of the member bodies casting a vote.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. ISO shall not be held responsible for identifying any or all such patent rights.
ISO 20242-2 was prepared by Technical Committee ISO/TC 184, Automation systems and integration,
Subcommittee SC 5, Architecture, communications and integration frameworks.
ISO 20242 consists of the following parts, under the general title Industrial automation systems and
integration — Service interface for testing applications:
⎯ Part 1: Overview
⎯ Part 2: Resource management service interface
The following parts are planned:
⎯ Part 3: Virtual device service interface
⎯ Part 4: Device capability profile template
⎯ Part 5: Application program service interface
⎯ Part 6: Conformance test methods, criteria and reports
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ISO 20242-2:2010(E)
Introduction
The motivation for ISO 20242 stems from international automotive industries and their suppliers to facilitate
the integration of automation and measurement devices, and other peripheral components for this purpose,
into computer-based applications. It defines rules for the construction of device drivers and their behaviour in
the context of an automation application, or a measurement application, or an automation and measurement
application.
The main goal of ISO 20242 is to provide users with:
⎯ independence from the computer operating system;
⎯ independence from the device connection technology (device interface/network);
⎯ independence from device suppliers;
⎯ the ability to certify device drivers with connected devices and their behaviour in the context of a given
computer platform;
⎯ independence from the technological device development in the future.
ISO 20242 will not force the development of new device families or the use of special interface technologies
(networks). It encapsulates a device and its communication interface to make it compatible with other devices
of that kind for a given application.

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INTERNATIONAL STANDARD ISO 20242-2:2010(E)

Industrial automation systems and integration — Service
interface for testing applications —
Part 2:
Resource management service interface
1 Scope
This part of ISO 20242 defines a service interface that provides a generic service access point for managing
and operating the resources supported by the operating system of a computer and its peripherals, including
special hardware on plug-in boards that are used in computer-assisted testing applications. The resource
management service interface is intended to be implemented in a manner that offers the exposed services of
a computing platform adapter to be generic and independent of the operating system and its communication
interfaces.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated
references, only the edition cited applies. For undated references, the latest edition of the referenced
document (including any amendments) applies.
ISO 20242-1, Industrial automation systems and integration — Service interface for testing applications —
Part 1: Overview
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 20242-1 and the following apply.
3.1
device driver
software module providing an ISO 20242-specified interface with service functions to call a platform adapter to
access physical devices
3.2
platform adapter
software module providing a resource management service interface as defined in this part of ISO 20242,
which encapsulates the computer platform, including the operating system, the hardware and its peripherals
4 Symbols and abbreviated terms
CNF, Cnf Confirm (service primitive)
IND, Ind Indication (service primitive)
REQ, Req Request (service primitive)
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ISO 20242-2:2010(E)
RMS Resource Management Services
RMSI Resource Management Service Interface
RSP, Rsp Response (service primitive)
SAP Service Access Point
5 Conventions for service definitions and procedures
5.1 General
This part of ISO 20242 uses the descriptive conventions given in ISO/IEC 10731.
The interface between the user of RMS and the provider of RMS is described by service primitives that
convey parameters. Since data transmission aspects are outside the scope of ISO 20242, only the request
and confirm primitives are used to describe events occurring at the RMS service provider. Indication and
response primitives are used to handle events occurring at the RMS service provider. The service model,
service primitives and sequence diagrams are abstract descriptions; they do not represent a specification for
implementation.
Annex A contains rules for example implementations.
5.2 Parameters
Service primitives, used to represent service user/provider interactions (see ISO/IEC 10731), convey
parameters that indicate information used and exchanged in these interactions.
This part of ISO 20242 uses a tabular format to describe the component parameters of the RMS primitives, as
shown in Table 1. The parameters that apply to each group of RMS primitives are set out in tables throughout
the remainder of this part of ISO 20242. Each table consists of three columns, where the first column contains
the name of the service parameter, the second column contains the input parameters of either the request or
indication primitives, and the third column contains the output parameters of either the confirm or response
primitives.
One parameter (or part of it) is listed in each row of each table. Under the appropriate service primitive
columns, the following codes are used to specify the type of usage of the parameter on the primitive and
parameter direction specified in the column:
a) M: parameter is mandatory for the primitive;
b) C: parameter is conditional upon other parameters or upon RMS capabilities;
c) S: parameter is a selected item;
d) (blank): parameter is not conveyed by the RMS user or the RMS provider.
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ISO 20242-2:2010(E)
Table 1 — Tabular format for service primitive parameters
Parameter name REQ or IND CNF or RSP
Argument M
   Parameter 1 M
   Parameter 2 C

Result (+) S
   Parameter 3 M
   Parameter 4 C

Result (-) S
   Parameter 5 M

5.3 Service procedures
5.3.1 RMS confirmed services
An RMS user submits a request primitive to the RMSI. It is implied that the service access point (SAP) exists.
The corresponding service processing entity delivers a confirmation primitive to the user after all necessary
interactions are finished or an error occurred.
5.3.2 RMS event handling
The user creates a service access point (SAP) at RMSI for handling events. An event is signalled with an
indication primitive at this access point. The user of RMSI issues a response primitive after all necessary
interactions are finished or an error occurred (see Figure 1).

request confirm indication response
SAP SAP
Interface
Service
local service
local event
provider
processor

Figure 1 — Handling local events with RMS
5.4 Service primitives and state diagrams
If needed, UML state diagrams are used to describe the behaviour of RMS. In such diagrams, only the service
name is used to describe a state transition where no explicit state between request and confirm primitives is
necessary [see Figure 2 b)]. Otherwise an extra state of processing the service is denoted [see Figure 2 a)].
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ISO 20242-2:2010(E)

A)
service.request service.confirm
Service Processing
RMS State X RMS State Y
State
B)
service
RMS State U RMS State V

Figure 2 — State transitions caused by services
6 Resource Management Services
6.1 Overview
The RMSI shall provide generic management support services, generic operating support services, and
generic input/output services.
The input/output services access another subjacent layer providing extended services. Extended services are
introduced to describe the structure of loadable resources for different kinds of periphery interfaces (see
Figure 3).
NOTE 1 ISO 20242 does not define the methods for integrating entities with extended services into the RMS provider,
as that will depend on the computer operating system and the programming language used for implementing service
providers. However, the extended services need to be described to enable the extension of input/output services for
different peripheral interfaces without changing the RMS provider. See Annex A for an implementation example.
NOTE 2 There are additional cascading methods described in Annex B for using the RMSI in more complex structures
of device and equipment integration.

Resource Management Service Interface
management support services input/output services
operation support services
Extended Service Interface
extended services

Figure 3 — Service users and providers at the RMSI
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ISO 20242-2:2010(E)
6.2 List of services
6.2.1 Generic management support services
Generic management support services are used for handling the access to other services and for initiating
(and loading, if necessary) extended service providers. Table 2 gives an overview of these services.
Table 2 — Generic management support services
Service Name for Remarks
identification
Get Service Reference getFuncAddress Get the reference for a service by identifier (name and/or number)
and version number.
Initiate Periphery Interface io_initiate Get the identifier for a specified interface type and load an extended
Type service provider for this type (if necessary).
Conclude Periphery io_conclude Release a type identifier and close the extended service provider for
Interface Type this type (if existing).

6.2.2 Generic input/output services
Generic input/output services are used for communication with real devices and for configuration and control
of peripheral interfaces. Table 3 gives an overview of these services.
Table 3 — Generic input/output services
Service Name for Remarks
identification
Open Periphery Interface io_open Open a peripheral interface for data transmission and configure the
Channel interface.
Reconfigure Periphery io_config Change the configuration of an interface without closing it, e.g.
Interface Channel change transmission parameters.
Read Data io_read Fetch received data at a peripheral interface.
Write Data io_write Deliver data to a peripheral interface for transmitting.
Execute Operation io_execute Execute an operation belonging to a peripheral interface channel.
This is comparable to handling both read and write data with one
service (data exchange).
Cancel Communication io_cancel Cancel a Read Data, Write Data or Execute Operation service and
prepare the interface for new requests.
Get Periphery Interface io_stat Investigate the status of a peripheral interface.
Channel Status
Clear Read Buffer io_clear Delete the contents of the input buffer of a peripheral interface.
Close Peripheral Interface io_close Close a peripheral interface.
Channel
Signal Event io_event Indicating a local event and responding to the event source.

Generic input/output services are transferred to corresponding extended services (see Table 4) if an extended
service provider is loaded for the specified type of interface.
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ISO 20242-2:2010(E)
6.2.3 Extended services
Extended services are not visible to the user of the RMSI; they are defined in this part of ISO 20242 to enable
a hierarchical modular structure of RMS implementation by using extended service providers. These extended
services are substantially the same as the generic input/output services of RMS.
Table 4 — Extended services for peripheral interfaces
Service Name for Remarks
identification
Initiate Extended Interface ext_initiate Set the identifier for a specified peripheral interface type.
Type
Conclude Extended ext_conclude Release the type identifier of ext_initiate.
Interface Type
Open Extended Interface ext_open Open a peripheral interface for data transmission and configure the
interface.
Reconfigure Extended ext_config Change the configuration of a peripheral interface without closing it,
Interface e.g. change transmission parameters.
Read Extended Interface ext_read Fetch received data at a peripheral interface.
Data
Write Extended Interface ext_write Deliver data to a peripheral interface for transmitting.
Data
Execute Extended Interface ext_execute Execute an operation belonging to a peripheral interface. This is
Operation comparable to handling read and write data with one service (data
exchange).
Cancel Extended ext_cancel Cancel a Read Extended Interface Data, Write Extended Interface
Communication Data or Execute Extended Interface Operation service and prepare
the interface for new requests.
Get Extended Interface ext_stat Investigate the status of an interface.
Status
Clear Extended Interface ext_clear Delete the contents of the input buffer of a peripheral interface.
Read Buffer
Close Extended Interface ext_close Close a peripheral interface.
Signal Extended Event ext_event Indicating an extended event and awaiting a response.

6.2.4 Operating support services
Operating support services (see Table 5) provide access to memory, timer control, semaphores and other
resources of the computer operating system.






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ISO 20242-2:2010(E)
Table 5 — Operating support services
Service Name for Remarks
identification
Allocate Memory os_allocate Allocate coherent data space of specified size.
Reallocate Memory os_reallocate Change size of allocated data space.
Free Memory os_free Release allocated data space.
Get Time os_time Investigate the local time.
Get Process Time os_clock Investigate the CPU-time for a process.
Wait os_delay Temporize a specified amount of time.
Create Timer os_settimer Create and start a timer.
Signal Timer Event os_timerEvent Indicating that a timer elapsed and awaiting a response.
Remove Timer os_killtimer Stop and remove a timer.
Create Light Process Timer os_setLPtimer Create and start a light process timer; resolution and accuracy
depend on the light process.
Signal Light Process Timer os_LPtimerEvent Indicating that a light process timer elapsed and awaiting a response.
Event
Remove Light Process os_killLPtimer Stop and delete a light process timer.
Timer
Identify Light Process os_getLPnumber Identify the actual light process.
Create Counted Semaphore os_createSem Create a counted semaphore to control multiple concurrent use of
resources.
Wait for Counted os_waitSem Wait for a free access to a protected resource.
Semaphore
Release Counted os_releaseSem Release the access to a protected resource.
Semaphore
Delete Counted Semaphore os_deleteSem Delete a counted semaphore.
Create Private Semaphore os_createMutex Create a private semaphore to control access to resources by
different light processes with mutual exclusion.
Wait for Private Semaphore os_waitMutex Wait for a free access to a protected resource.
Release Private Semaphore os_releaseMutex Release the access to a protected resource.
Delete Private Semaphore os_deleteMutex Delete a private semaphore.
Open Debug Log os_openDebug Open a text log for debug messages.
Write Debug Message os_writeDebug Send message to text log.
Close Debug Log os_closeDebug Close a text log.

6.3 Management support services
6.3.1 Get Service Reference service
6.3.1.1 Service overview
The Get Service Reference service is used to get a reference for other version-dependent resource
management services. This service is requested by the RMS user for each resource management service that
is needed for an application.
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ISO 20242-2:2010(E)
6.3.1.2 Service parameter structure
The service parameters for the Get Service Reference service are shown in Table 6.
Table 6 — Get Service Reference parameter structure
Parameter name Req Cnf
Argument M
 Service identifier (name) M
 Proposed version number M

Result (+) S
 Service reference M

Result (-) S

6.3.1.3 Service parameters
6.3.1.3.1 Argument
The argument contains the parameters of the service request.
6.3.1.3.2 Service identifier
This parameter identifies the service for which the reference is requested.
6.3.1.3.3 Proposed version number
This parameter specifies the version which the RMS user requests for this service.
6.3.1.3.4 Result (+)
This selection type parameter indicates that the service request succeeded.
6.3.1.3.5 Service reference
This parameter contains a reference to identify the service of the proposed version number.
6.3.1.3.6 Result (-)
This selection type parameter indicates that the service request failed.
6.3.1.4 Service procedure
If a service of the specified name and with the specified version number is available, a reference to it is
created and submitted to the requester.
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ISO 20242-2:2010(E)
6.3.2 Initiate Peripheral Interface Type service
6.3.2.1 Service overview
This service requests the availability of an interface with the specified type name. If a name for an extended
service provider is specified with this request, the extended provider will be loaded and the availability of the
specified interface is requested at this provider.
6.3.2.2 Service parameter structure
The service parameters for this service are shown in Table 7.
Table 7 — Initiate Peripheral Interface Type parameter structure
Parameter name Req Cnf
Argument M
 Interface type name M
 Extended services provider name C

Result (+) S
 Interface type identifier M

Result (-) S
 Error M

6.3.2.3 Service parameters
6.3.2.3.1 Argument
The argument contains the parameters of the service request.
6.3.2.3.2 Interface type name
This parameter contains the name of the interface type.
6.3.2.3.3 Extended services provider name
This conditional parameter, if specified, contains the name of an extended services provider that handles the
input/output services for this type of interface.
6.3.2.3.4 Result (+)
This selection type parameter indicates that the service request succeeded.
6.3.2.3.5 Interface type identifier
This parameter contains a number identifying this interface type for other service requests.
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ISO 20242-2:2010(E)
6.3.2.3.6 Result (-)
This selection type parameter indicates that the service request failed.
6.3.2.3.7 Error
This parameter indicates that one of the following conditions exists:
⎯ unknown or unavailable interface type;
⎯ unknown, unloadable, or unusable extended service provider;
⎯ interface type already initialized;
⎯ memory error occurred while loading the extended service provider;
⎯ hardware error detected.
6.3.2.4 Service procedure
This service checks the availability of an interface with the specified type. If a name for an extended service
provider is given, the applicable provider is loaded, if not present, and checked for the specified type of
interface.
6.3.3 Conclude Peripheral Interface Type service
6.3.3.1 Service overview
This service concludes a peripheral interface which has been initiated before.
6.3.3.2 Service parameter structure
The service parameters for this service are shown in Table 8.
Table 8 — Conclude Peripheral Interface Type parameter structure
Parameter name Req Cnf
Argument M
 Interface type identifier M

Result (+) S

Result (-) S
 Error M

6.3.3.3 Service parameters
6.3.3.3.1 Argument
The argument contains the parameters of the service request.
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ISO 20242-2:2010(E)
6.3.3.3.2 Interface type identifier
This parameter contains the identifier of the type which was the result of the service Initiate Periphery
Interface Type.
6.3.3.3.3 Result (+)
This selection type parameter indicates that the service request succeeded.
6.3.3.3.4 Result (-)
This selection type parameter indicates that the service request failed.
6.3.3.3.5 Error
This parameter indicates one of the following conditions exists:
⎯ unknown or unavailable interface type identifier;
⎯ extended services provider could not be released;
⎯ memory error occurred while releasing the extended service provider;
⎯ hardware error was detected.
6.3.3.4 Service procedure
This service checks if this type of peripheral interface can be released. If this type is served by an associated
extended service provider, the service also checks to see if the associated extended service provider can be
released. An extended service provider can only be released if all contained peripheral interfaces of all types
are released.
6.4 Input/output services
6.4.1 Open Peripheral Interface Channel service
6.4.1.1 Service overview
This service is used to open a communication channel for a peripheral interface of specified type and
configures the channel for the user's needs.
6.4.1.2 Service parameter structure
The service parameters for this service are shown in Table 9.




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ISO 20242-2:2010(E)
Table 9 — Open Peripheral Interface Channel parameter structure
Parameter name Req Cnf
Argument
M
 Interface type identifier M
 Interface channel name
C
 List of configuration parameters M
 Confirmed services access point reference M
 Event services access point reference M

Result (+) S
 Interface channel identifier M

Result (-) S
 Error M

6.4.1.3 Service parameters
6.4.1.3.1 Argument
The argument contains the parameters of the service request.
6.4.1.3.2 Interface type identifier
This parameter identifies the type of the peripheral interface.
6.4.1.3.3 Interface channel name
This parameter identifies a communication channel of the specified type. It may be omitted, if channels are
instantiated by RMS and there is no assignment of unique peripheral connectors necessary (e.g. bus
systems).
6.4.1.3.4 List of configuration parameters
The list of configuration parameters, which is outside the scope of ISO 20242, depends on the type of the
selected peripheral interface. A selected peripheral interface specifies the necessary parameters for its
configuration.
If there are configuration parameters valid for all channels o
...