# MessageSignal
<a name="API_MessageSignal"></a>

The decoding information for a specific message which support higher order data types. 

## Contents
<a name="API_MessageSignal_Contents"></a>

 ** structuredMessage **   <a name="iotfleetwise-Type-MessageSignal-structuredMessage"></a>
The structured message for the message signal. It can be defined with either a `primitiveMessageDefinition`, `structuredMessageListDefinition`, or `structuredMessageDefinition` recursively.  
Type: [StructuredMessage](API_StructuredMessage.md) object  
 **Note: **This object is a Union. Only one member of this object can be specified or returned.  
Required: Yes

 ** topicName **   <a name="iotfleetwise-Type-MessageSignal-topicName"></a>
The topic name for the message signal. It corresponds to topics in ROS 2.   
Type: String  
Length Constraints: Minimum length of 1. Maximum length of 150.  
Pattern: `[a-zA-Z0-9_\-#:./]+`   
Required: Yes

## See Also
<a name="API_MessageSignal_SeeAlso"></a>

For more information about using this API in one of the language-specific AWS SDKs, see the following:
+  [AWS SDK for C\$1\$1](https://docs.aws.amazon.com/goto/SdkForCpp/iotfleetwise-2021-06-17/MessageSignal) 
+  [AWS SDK for Java V2](https://docs.aws.amazon.com/goto/SdkForJavaV2/iotfleetwise-2021-06-17/MessageSignal) 
+  [AWS SDK for Ruby V3](https://docs.aws.amazon.com/goto/SdkForRubyV3/iotfleetwise-2021-06-17/MessageSignal)