Interoperability can be defined as the ability of a user to seamlessly purchase, deploy and use a system form multiple suppliers or the ability of a two or more systems or components to exchange information and to periodically use the information that has been exchanged. 

There are several levels of interoperability: 

  • Meter level: look and feel, mechanical   mount, operation, protocols
  • System level: billing, tokens, vending   standard, infrastructure, protocols
  • Application level: prepayment, post-  payment, smart metering 

Interoperable systems normally conform to one or more open standards.

An open standard is defined as a standard that is available to any person wishing to develop a product that conforms to that standard, with no restrictions such as patents and trademarks, or reasonable negotiable licences to use such a standard. Examples of organizations that publish open standards are:

  • IEC
  • IEEE
  • ISO

The use of the open standard may be subject to the purchase of the standard from the organization, or membership of the organization.

The STS uses interoperable standards, i.e. IEC62055-41, IEC62055-51, and IEC62055-52, as well as several companion specifications, thus making the STS products interoperable. Any system that uses these standards will be able to function between manufacturers. So, a meter purchased from one manufacturer will function correctly with a vending system form another manufacturer, provided that both are certified as STS compliant.