What is DDS?

DDS provides a way for devices to exchange data on local or remote networks. It is a small foot print network stack that consumes minimal resources and can be deployed on any device. Small embedded sensors running on machines?in the field, or, cloud servers running in?data centres can all run DDS.

DDS will take care of data exchange between any of these devices.

How Does DDS Work?

DDS works on the publish/subscribe principle. This means data exchange is peer to peer and does not need a message broker or central server. A device with data to offer to a network (publisher) is matched with a device which has a requirement to receive this data(subscriber). Matching is done via Data TOPICS and a discovery process. A Data TOPIC could be a package of machine health information such as temperatures, speeds, working hours and fault codes. This Data TOPIC could be required by a neighbouring device of the same type, a data logger, a cloud server, a PLC controller and/or a measuring diagnostic tool. In other words any DDS device can exchange data with any other DDS device. Data can be exchanged between publishers and subscribers via unicast, multicast or broadcast meaning data from 1 device can easily reach 1000s of other devices.

Why Would I Use DDS?

DDS saves engineering time and money by automating data exchange between devices. As networks grow to 1000’s of?devices then network configuration and?management can be cumbersome. If each new device added to a network needs?configuring with IP addresses and port?numbers then this can consume large amounts of engineering time.

DDS takes care of this in the back ground and makes sure network participants can exchange data on the basis of TOPICs. DDS therefor allows networks to scale automatically. 1000’s of devices can join?a network auto configure and then?publish or subscribe to data TOPICs. Very often IIOT network scenarios are dynamic meaning 1000’s of devices can leave a network too. DDS ensures that large numbers of devices can join or leave a network automatically.

How Is Data Transfer Flexibility Achieved?

DDS provides 25 different quality of?service (QOS) configurations. This means?data subscribers can choose?communication profiles appropriate to their requirements. Examples of DDS?QOS configurations are:

■?History: Specify how much data history is available to new network participants.

■?Reliability: Specify if data receipt can be tolerant of dropped packets.

■?Deadline: A Network mechanism that will error handle late delivery of messages.

■?Filtration: A subscriber may not want to receive every data sample for a particular topic.

■?Ownership Strength: A subscriber can choose which duplicate data to use based on publisher strength.

How Long Has DDS Been Around?

DDS has been in existence since 2001. It was started as a solution to problem with stove pipe communications in US Navy applications. DDS was designed to provide a data centric communications environment for seaborne applications to enable many different sub systems to communicate.

Is DDS An Open Standard?

Yes DDS is an open standard with multiple vendors and a governing standards body. The standards body is the Object Management Group(OMG). There are multiple vendors of DDS which means there is no commercial lock in with any implementation. Vendor meetings under the governance of OMG meet 4 times per year to discuss improvements and changes.

What If My IIOT Device Has Limited Resources?

Hamersham is the European distributor for Twin Oaks Computing. Twin Oaks Computing make a world leading small foot print DDS implementation: CoreDx. Flash requirements are 600Kb and memory requirements for a typical applications is <250Kb. This means the Twin Oaks CoreDx DDS can be deployed in edge applications where resources are limited or larger cloud computers where resources are readily available. Twin Oak CoreDx allows the same DDS implementation to be implemented regardless of application type.

How Do I Test DDS FOC?

Hamersham recognises that engineering concept testing is usually budget constrained and therefor we offer extended free evaluations for all of our products. When you are evaluating you will received customer support to help get DDS up and running on your device.

What Support And Service Can I Expect?

Hamersham and Twin Oaks are committed to excellent customer service. If something is not working then we will work very hard to identify the problem. Fast response and very clear communication means we can get your DDS networking project running faster.

For any questions or inquiries, please send me a direct message.