ThingWorx Edge C SDK > How to Set Up an Application > Initiating Interactions with a ThingWorx Platform > Write a Property
  
Write a Property
This helper function writes a new value for a property of a specific entity on ThingWorx Platform.
enum msgCodeEnum twApi_WriteProperty(enum entityTypeEnum entityType, char * entityName, char * propertyName, twPrimitive * value, int32_t timeout, char forceConnect)
* 
This function directly targets a specific property on the ThingWorx Platform and creates the equivalent of an HTTP PUT request encoded as an AlwaysOn message. It is not a VTQ type of function in that no client-side timestamps are acquired when you use this function. When it receives this PUT request, the ThingWorx Platform uses the time that the data arrived on the platform to complete the VTQ that is logged when data arrives. Quality is assumed to be GOOD.
The following table describes the parameters for this helper function:
Parameter
Type
Description
entityType
Input
The type of entity that the property belongs to. Enumeration values can be found in twDefinitions.h.
entityName
Input
The name of the entity that the property belongs to.
propertyName
Input
The name of the property to retrieve.
value
Input
A pointer to a twPrimitive that contains the value to set for the property. Once called, the calling function retains ownership of this pointer and must manage the memory lifecycle.
* 
The called function will alter the contents of this primitive, so the original contents cannot be relied upon after the function returns.
timeout
Input
The time (in milliseconds) to wait for a response from the platform. A value of -1 uses the DEFAULT_MESSAGE_TIMEOUT as defined in twDefaultSettings.h.
forceConnect
Input
A Boolean value. If true and the API is in the disconnected state of the duty cycle, the API will force a reconnect to send the request.
Return:
msgCodeEnum — the result of the call. Refer to twDefinitions.h for the enumeration definition.