Generic CAN

CAN Bus semantics

This driver is a generic purpose driver. It allows implementing a basic CAN bus listening or writing scenarios.

CAN bus open is a specific protocol built on top of CAN bus.

Connection String Options

Name

Type

Default Value

Required

Description

Name

Generic CAN

Code

genericcan

Maven Dependency

 
<dependency>
  <groupId>org.apache.plc4x</groupId>
  <artifactId>plc4j-driver-can</artifactId>
  <version>0.13.0-SNAPSHOT</version>
</dependency>

Default Transport

socketcan

Supported Transports

  • socketcan

Config options:

node-id

INT

Node id of the target device.

request-timeout

INT

1000

Default timeout for all types of requests.

Transport config options:

socketcan
Name Value Description

Supported Operations

publish

write

Allows to publish a CAN frame via CAN transport.

receive

subscribe

This operation allows listening for incoming data or requests.

More details on the driver

Given popularity of CAN in multiple market segments there is variety of protocols which can’t be published. Also, for many cases which are data acquisition oriented it is necessary to tap only parts of communications.

This driver allows to model incoming and outgoing communication using plain Apache PLC4X api. The written CAN data is constructed from fields submitted via write request builder. The receiving data is transformed in similar fashion, based on subscribed fields.

Address format

Service Format Supported operations Description

n/a

nodeId:type[arraySize]

  • write

  • subscribe

There is only one syntax which is currently supported by this driver.

Pay attention. You can use multiple fields to write and subscribe actual data. All fields must sum to up to 64 bits. If you subscribe less, then remaining data is discarded and not available via PLC4X api.

The data will be sent in the same order as fields.

Below table contains type mapping defined in Generic CAN driver.

CANopen Type

Length (in bits)

PLC4X Type

BOOLEAN

1

BOOL

UNSIGNED8

8

USINT

UNSIGNED16

16

UINT

UNSIGNED24

24

UDINT

UNSIGNED32

32

UDINT

UNSIGNED40

40

ULINT

UNSIGNED48

48

ULINT

UNSIGNED56

56

ULINT

UNSIGNED64

64

ULINT

INTEGER8

8

SINT

INTEGER16

16

INT

INTEGER24

24

DINT

INTEGER32

32

DINT

INTEGER40

40

LINT

INTEGER48

48

LINT

INTEGER56

56

LINT

INTEGER64

64

LINT

REAL32

32

REAL

REAL64

64

LREAL

The type table is similar to CANopen. Main difference is lack of support for string types.