FMS Tell Tale Status

FMS Tell Tale Status Introduction

Tell Tale was created in order to receive all available dashboard indication events that are available on truck via FMS protocol according to J1939 standard. SAE J1939 is the vehicle bus standard used for communication and diagnostics among vehicle components. Based on the same architecture FMS protocol dedicated to telematics systems is available. It has certain standardized parameters available, such as fuel consumption, engine work-hours, etc. Please visit http://www.fms-standard.com/ for more information and message structure.

What parameters should be enabled

Configurable parameters via SMS/GPRS commands can be found at FMB640_Device_Family_Parameter_list#FMS

How to parse Tell Tale data

4 FMS IO elements created: Tell Tale ID0 Tell Tale ID1 Tell Tale ID2 Tell Tale ID3

Each ID represents Block ID of Tell Tale.

IO elements store information that is received from FMS Tell Tale Status message (CAN ID - 0x00FD7D). Status message sends Data Block information in Data Byte 1. Block ID is determined by Data Byte 1 first 4 Bits. Example in hexadecimal first 4 bits where X – random byte value. X0₁₆ – Block ID 0 - FMS IO element Tell Tale ID0 X1₁₆ – Block ID 1 - FMS IO element Tell Tale ID1 X2₁₆ – Block ID 2 - FMS IO element Tell Tale ID2 X3₁₆ – Block ID 3 - FMS IO element Tell Tale ID3

Once Block ID is captured all 8 bytes of Tell Tale message are saved to corresponding Tell Tale IO element.

Example of FMS Tell Tale status data:

When device is powered up all elements are be updated to the first corresponding message.

After 4 seconds (1000 ms per Block ID) all values will be captured again. Device checks last saved value of Tell Tale IO elements and if it is changed – values are updated.

Quick links

FMS-Standard Description Document

Tell Tale only available on vehicles that support FMS standard

Tell Tale examples are provided in FMS-Standard Description document that is publicly available

Availability of parameter depends on vehicle’s model and configuration of the FMS interface of the truck.

Note: FMS Tell Tale status is supported on FMB640 FMC640 FMM640 FMB630 FM6300 devices. Also please check firmware errata table to see from which firmware version this feature is available.