SSB: Constraints and Limitations

Overview

There are four primary components used in a system using Sparkplug SiteWise Bridge. These are:

• Edge Gateways publishing Sparkplug based MQTT data
  • Our examples will use Ignition+MQTT Transmission for the Edge Gateway.
• An MQTT Server
  • This could be AWS IoT Core or any other v3.1.1 compliant MQTT Server
• Sparkplug SiteWise Bridge
• AWS IoT SiteWise

There are some translations that need to take place between the components and these platforms have different capabilities that result in some limitations in how an Edge Gateway can be configured. For example, UDTs in Ignition support more data types that AWS IoT SiteWise does. As a result, use of data types in Ignition must be limited to those supported by AWS IoT SiteWise in order for data to properly show up and be updated in AWS SiteWise.

Supported Data Types

AWS IoT SiteWise only supports Booleans, Integers, Doubles, and Strings. As a result, this is the list of data types in Ignition that are supported for consumption into AWS IoT SiteWise

• Boolean
• Byte
  • Will be up-casted to an Integer in SiteWise
• Short
  • Will be up-casted to an Integer in SiteWise
• Integer
• Float
  • Will be up-casted to an Double in SiteWise
• Double
• String

Any non-supported data type will be converted to a String in SiteWise and the measurement value for any instance will show an error with a message similar to "Long is not a valid datatype"