OpenLCB Specifications

This page provides access to the OpenLCB™ Standards and Technical Note documents.

OpenLCB is not a formal standards-making body, but we are interested in making it clear what’s required and not required for interoperation between OpenLCB nodes. Therefore, we are creating a series of “standards” and corresponding explanatory “technical notes” as specific documents. “Standards” are normative, to the extent that anything this bunch of happy campers does can be proscriptive. “Technical Notes” are coupled statements of explanations and additional information that go with each standard. For more information on the conventions used when writing OpenLCB standards and technical notes, please see the separate “conventions” page.

For background information, informal and development documents, etc, please see the “documentation” index page.

These documents describe the 0.5 version of the OpenLCB protocols.

Layered View

OpenLCB has been created as a layered family of protocols. The basic structure is along the lines of the wildly successful architecture of the ARPA TCP/IP family of protocols. For use on e.g. Controller Area Network (CAN), OpenLCB has to deal with lower-level concepts than the TCP/IP stack does, so OpenLCB is structured like a hybrid of the TCP/IP with the lower-level physical-layer and data-link-layer concepts of the ISO model.

In the following, items marked in light green are complete and adopted. Items marked in teal are in their penultimate form, and only awaiting final comments from the OpenLCB egroup. Items marked in blue are solid drafts, with the next step being discussion and adoption. Uncolored links are to informal and preliminary documents which will eventually form drafts, and then adopted standards and technical notes. The right two columns list the corresponding ISO and TCP/IP layer names, and are not part of OpenLCB.

(We need a strong technical, non-normative introduction of some sort. It’s not clear where it goes in this view of the table of contents. See the prior “Technical Introduction” development document for an example of possible content.)

Common

CAN

TCP/IP

OSI Model Layer

TCP/IP Model Layer

Time Broadcast Protocol
[prelim Std (.pdf)
(.odt)]
[prelim TN (.pdf)
(.odt)]
[Older Working Note (.pdf)]

Train Control Protocol
[prelim Working Note (.pdf)
(.odt)]
[dev note]
Traction Proxy Protocol [obsolete]
[prelim Working Note (.pdf)
(.odt)]
Simple Train Info Protocol
[prelim Std (.pdf)
(.odt)]
[prelim TN(.pdf)
(.odt)]

Display Protocol [dev note]

Remote Button Protocol [prelim TN (.pdf)(.odt)]

Ident Method [dev note]

Event Teaching/Learning Protocol [dev note 1] [dev note 2] [dev note 3]

Abbreviated Configuration Description Information [obsolete, merged into Configuration Description Information] [obsolete Std
(.pdf)(.odt)]
[obsolete TN (.pdf)(.odt)]
and related:

Simple Node Identification Protocol [Std
(.pdf)(.odt)]
[TN (.pdf)(.odt)]

Configuration Description Information [Std (.pdf)(.odt)]
[TN (.pdf)(.odt)]

Memory Configuration Protocol [Std (.pdf)(.odt)]
[TN (.pdf)(.odt)]

Producer/Consumer Protocol [dev
note] (see Event Transport below)

Protocol Identification
Protocol [obsolete, merged into Message Network] [obsolete Standard][obsolete Technical
Note]

Application

Application

Presentation

Session

Stream Transport

OpenLCB-CAN Stream
Transport [dev note]

[preliminary Standard .odt preliminary Technical Note .odt]

OpenLCB-TCP/IP Stream Transport

Transport

Transport

Datagram Transport
[Standard (.pdf)(.odt)]
[TN (.pdf)(.odt)]

Future versions:
None at the moment

OpenLCB-CAN Datagram Transport
(See General Spec)

OpenLCB-TCP/IP Datagram Transport

OpenLCB Event Transport
[Standard (.pdf)(.odt)]
[TN (.pdf)(.odt)]

Future versions:
None at the moment

Event Identifiers

[working note]

[Std (.pdf)(.odt)]
[TN (.pdf)(.odt)]

OpenLCB-CAN Event Transport
(See General Spec)

OpenLCB-TCP/IP Event Transport

Message Network
[Std (.pdf)(.odt)]
[TN (.pdf)(.odt)]

[MTI allocations (.pdf)
(.ods)]

Network

Internet/Network

Unique Identifiers (Node
IDs)
[Standard .pdf .odt] [Technical
Note .pdf .odt]

Future versions:
None at the moment

OpenLCB-CAN Frame Transfer

[Standard (.pdf)(.odt)]
[Technical Note (.pdf)(.odt)]

Future versions: Note at the moment

OpenLCB-TCP Transfer
[prelim Std (.pdf)(.odt)]

[prelim TN (.pdf)(.odt)]

Data Link

Network Interface/Subnetwork

OpenLCB-CAN
Physical Layer
[Standard .pdf .odt]
[Technical Note .pdf .odt]

Future
versions: None at the moment

(none)

Physical Interface

Common Information TN (.pdf)
(.odt)

Future version: None at the moment

Glossary of OpenLCB terms
(.pdf) (.odt)

Future version: None at the moment

Background Info

Background Info

Other Documents

General

We need a strong technical, non-normative introduction of some
sort. See the prior “Technical
Introduction” development document.

Documentation conventions and general background information on
data types, etc, can be found in the “Common
Information TN” adopted version: (.pdf)
(.odt)
Future version: None at the moment.

Glossary of OpenLCB terms
accepted version: (.pdf) (.odt)
Future version: None at the moment.

Allocation Tables

Various numbers have to be allocated and recorded in OpenLCB. This
section documents those.

Unique IDs and Node
IDs

OpenLCB node IDs are a form of unique identifier which are
allocated as described in an adopted
[Standard (.pdf)(.odt)]
and [Technical Note (.pdf)(.odt)].

Specific values are recorded and make available via OpenLCB web
pages:

Message Type
Indicators (MTIs)

OpenLCB Message Type Indicators (MTIs) are allocated as described
in the message-level documentation. The specific assigned values are
tracked in a [spreadsheet (.pdf)(.ods)].

Event IDs

There’s a [working
note] on assignment of Event IDs. The specific assigned values
are tracked in a [spreadsheet (.pdf)(.ods)].

Protocol ID numbers

Protocol ID bits are defined at the Protocol Identification
Request message of the Message Network specification. [(.pdf)
(.odt)]

Datagram protocol IDs

The specific assigned values are tracked in a spreadsheet
[(.pdf)(.ods)].

Stream protocol IDs

The specific assigned values are tracked in a spreadsheet
[(.pdf)(.ods)].

Memory Spaces

The Memory Configuration Protocol defines memory spaces, some of
which are reserved for specific uses. [(.pdf)
(.ods)]

References

TCP/IP model

http://www.tcpipguide.com/free/t_TCPIPArchitectureandtheTCPIPModel-2.htm

http://www.davidchappell.com/HTML_email/Opinari_No9_01_04.html

OSI model

http://www.tcpipguide.com/free/t_OSIReferenceModelLayerSummary.htm