FMUSER INTERNATIONAL GROUP INC. 广州市汉婷生物技术开发有限公司
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13.2 Traffic Message Channel (TMC) Application Notes
13.2.1 Basic requirements
The TMC service can work only if there is an application that we can call 'TMC data provider'. The TMC data provider
collects all related information and translates it into RDS groups 8A type. The output of the TMC data provider must
be either by means of ASCII command G= or (more often) coded as UECP command with MEC 30. We will deal with
the second case in following text.
Nowadays the TMC service is coded as an ODA application. Thus there must be ODA AID groups 3A transmitted in
addition to the 8A groups. This can be done for example using the UECP MEC 24. The 3A groups typically carry fixed
content so in some cases they can be inserted into the RDS encoder also one-time using the command UDG1= or
UDG2=.
The Address and Site fields are optional. When the TMC data provider drives one RDS encoder only, these fields are
usually set to zero. However there can be more RDS encoders connected with various Address and Site values. Each
encoder will accept only the UECP records that match the Address and Site criteria. This configuration has been tested
successfully simulating a network of more than 60 encoders (equivalent to full load of one 9600 bps channel).
13.2.2 Preparing for the TMC transmission
1. Configure all static parameters of the RDS encoder. Enable the UECP (UECP=1
↵
*UECP
↵
).
2. Where required, store the fixed 3A groups using the commands UDG1= or UDG2=
(for example: UDG1=30100646CD46,30104080CD46
↵
*UDG1
↵
).
In this case make sure the UDG groups are included in the Group sequence (symbols X or Y).
3. Decide for the communication baudrate. Configure the RDS encoder and TMC data provider baudrate.
4. Configure the Site and Address values.
13.2.3 Application example
This application example shows TMC data and ODA AID information inserted by UECP commands 30 and 24.
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