Diagnostic Messages

Implementation related to diagnostic messages is located in uds.message sub-package.

UDS Message Implementation

Diagnostic messages implementation is divided into two parts:

  • UDS Message - storage for a new diagnostic message definition

  • UDS Message Record - storage for historic information of a diagnostic message that was either received or transmitted

UDS Message

UdsMessage class is meant to provide containers for a new diagnostic messages information. Once a diagnostic message object is created, it stores all diagnostic message information that were provided by a user. One can use these objects to execute complex operations (provided in other subpackages of uds) such as diagnostic messages transmission or segmentation.

Note

All UdsMessage attributes are validated on each value change, therefore a user will face an exception if one tries to set an invalid (e.g. incompatible with the annotation) value to any of these attributes.

Example code:

import uds

# example how to create an object
uds_message = uds.message.UdsMessage(payload=[0x10, 0x03],
                                     addressing_type=uds.transmission_attributes.AddressingType.PHYSICAL)

# raw message attribute reassignment
uds_message.payload = (0x62, 0x01, 0x23, 0x45, 0x67, 0x89, 0xAB, 0xCD, 0xEF)

# addressing attribute reassignment
uds_message.addressing_type = uds.transmission_attributes.AddressingType.FUNCTIONAL

UDS Message Record

UdsMessageRecord class is meant to provide containers for historic information of diagnostic messages that were either transmitted or received.

Note

A user should not create objects of this class in normal cases, but one would probably use them quite often as they are returned by other layers of uds package.

Warning

All UdsMessageRecord attributes are read only (they are set only once upon an object creation) as they store historic data and history cannot be changed (can’t it, right?).

A user will face an exception if one tries to modify any attribute.

UDS Messages Data

Implementation of data parameters that are part of diagnostic messages data.

UDS data parameters:

Service Identifiers

Implementation of Service Identifier (SID) values.

RequestSID

Enum RequestSID contains definitions of request Service Identifiers values.

Warning

RequestSID does not contain definition for every POSSIBLE_REQUEST_SIDS value as some Request SID values are reserved for further extension by UDS specification and others are ECU specific (defined by ECU’s manufacturer).

Note

Use add_member() method on RequestSID class to add Request SID value.

Example code:

import uds

# check if a value (0xBA in the example) is a Request SID value
uds.message.RequestSID.is_request_sid(0xBA)

# check if there is member defined for the value
uds.message.RequestSID.is_member(0xBA)

# example how to add a new Request SID value
new_member = uds.message.RequestSID.add_member("NewRequestSIDMemberName", 0xBA)

# check if the value was added as a new member
uds.message.RequestSID.is_member(new_member)
uds.message.RequestSID.is_member(0xBA)

ResponseSID

Enum ResponseSID contains definitions of response Service Identifiers values.

Warning

ResponseSID does not contain definition for every POSSIBLE_RESPONSE_SIDS value as some Response SID values are reserved for further extension by UDS specification and other are ECU specific (defined by ECU’s manufacturer).

Note

Use add_member() method on ResponseSID class to add Response SID.

Example code:

import uds

# check if a value (0xFA in the example) is a Response SID value
uds.message.ResponseSID.is_response_sid(0xFA)

# check if there is member defined for the value
uds.message.ResponseSID.is_member(0xFA)

# example how to add a new Response SID value
new_member = uds.message.ResponseSID.add_member("NewResponseSIDMemberName", 0xFA)

# check if the value was added as a new member
uds.message.ResponseSID.is_member(new_member)
uds.message.ResponseSID.is_member(0xFA)

Negative Response Codes

Enum NRC contains definitions of all common (defined by ISO 14229) Negative Response Codes values.

Warning

NRC does not contain definition for every possible NRC value as some of them are reserved for further extension by UDS specification and other are ECU specific (defined by ECU’s manufacturer).

Note

Use add_member() method on NRC class to add NRC value that is specific for the system that you communicate with.

Example code:

import uds

# check if a value (0xF0 in the example) is a NRC value
uds.message.NRC.is_member(0xF0)

# example how to add a new NRC value
new_member = uds.message.NRC.add_member("NewNRCMemberName", 0xF0)

# check if the value was added as a new member
uds.message.NRC.is_member(new_member)
uds.message.NRC.is_member(0xF0)