Template:FMX6 DM1 DM2

Introduction

With a professional device lineup, telltale information (dashboard indicators) from heavy-duty vehicles can be read remotely to identify a variety of issues. New feature of Diagnostic Trouble Code (DTC) reading will help to narrow down the specific faults happening in vehicles.

With {{{model}}} you can read 2 types of DTC messages based on J1939 protocol:

• DM1 – Active codes
• DM2 – Previously Active codes

{{{model}}} is able to read DM codes and pass them to the server in IO element. When active DM1 or DM2 messages appear on CAN line it is broadcasted very often – {{{model}}} device saves the codes into the internal memory and does not flood the server with irrelevant information – only new DTC codes are sent to the server.

Functionality Description

This functionality is available from Firmware version 03.01.02.rev.06 or higher.

For proper functionality, the device requires ignition to be active. Source of ignition and voltage level can be selected from System tab.

Ignition has to be active for at least 14 sec to start generating the DTC list. If ignition is turned off, the device will clean all DM1 and DM2 codes and functionality will not be working.

After the device is connected to the Configurator, there will be DM1 / DM2 tab made available. There is a configurable DM1 / DM2 Data source parameter. This parameter selects the CAN source based on which device will parse DM data from. Based on selected data source, device will also call a request for DTCs.

Note: The functionality is completely separated from the FMS source.

• NONE – Device will not use any CAN as data source
• CAN1 – Device will use CAN1 as data source
• CAN2 – Device will use CAN2 as data source
• BOTH – Device will use CAN1 and CAN2 as data source

Bellow Data source parameters there is a list of configurable IOs

„DTC DM1“ and “DTC DM2“ shows the last DTC that has been detected. „Active DM1 List“ and „Active DM2 List“ provides a list of all active DTCs for a given source.

Example of generating DM1 / DM2 list: To register DM1 code, it is required to send a command using (pgn 0xFEFA). Device will first check if such DTC code exist in the system (MCUID and CAN Source has to be unique for each DTC). Otherwise, DTC will be rejected.

9D000301:01:01

• 9D000301 – DTC in hexadecimal format
• 01 – MCU source that reported the DTC
• 01 – Device CAN source used (00 - CAN1, 01 - CAN2)

9D000302:02:01

• 9D000302 – DTC in hexadecimal format
• 02 – MCU source that reported the DTC
• 01 – Device CAN source used (00 - CAN1, 01 - CAN2)

Based on configured „Priority“, „Event Only“ and „Operand“ device will add this parameter to record.

To remove one of the DTC from DM1 list, DM2 code (pgn 0xFEFB) is required. Device will check if the sent DTC code exists in the system (MCUID and CAN Source has to be unique for each DTC). If sent DTC does not exist in the system, it will be rejected.

Based on previous example, sending DTC 9D000301 with MCUID 01 on CAN2, device remove this DTC from the system, as the result, this DTC is removed from „Active DM1 List“ and added to the „Active DM2 List“.

Log example:

That DTCs will be added to record and would be accessible on server. Data on server need to be converted from HEX to ASCII.

39443030303330323A30323A30313B -> (after conversion from hex to ANSCII) 9D000302:02:01;

39443030303330313A30313A30313B -> (after conversion from hex to ANSCII) 9D000301:01:01;

Functionality Block Diagram

Graphic representation of DM1 and DM2 functionality: