September 2010

AutomatedBuildings.com

Daikin Integration to BACnet, Modbus, KNX, WIFI, Mobile Apps
Intesis

(Click Message to Learn More)


"Open"
It can be argued that the word ‘Open’ is the most fundamental key word that has driven the BAS industry over the last decade and will continue to drive it in the future.

  Nirosha Munasinghe
Nirosha Munasinghe
MBusIT BSc BE (Hons) (Melb)
Product Development Manager,
Open General
 

Contributing Editor

The word ‘Open’ is a very powerful word in the English language. It can be argued that the word ‘Open’ is the most fundamental key word that has driven the BAS industry over the last decade and will continue to drive it in the future. Open standards, open protocols, open architecture and open web are some of the key concepts in the BAS industry. The Oxford dictionary defines open as allowing access, passage, or a view through empty space; not closed or blocked. Each one of us interprets the meaning in many ways. This is no different in the BAS industry. Therefore, although ‘Open’ has driven the BAS industry, it also has created confusion. This article unveils the intricacies of the word ‘Open’ in the BAS industry and defines key elements that the stakeholders need to be aware of when interpreting the word ‘Open’.

Articles
Interviews
Releases
New Products
Reviews
Editorial

Cube

Coming Events
Sponsors
Site Search
Blogs
Archives
Past Issues
Home

Belimo

Let’s examine few examples of extracts from BAS specifications:

All controls shall be open systems (BACnet or LonWorks) with a web based user interface

To ensure that uniform system standards are complied with, together with a competitive tendering process for new systems and maintenance of existing, the facility has adopted a BAS strategy for all new and existing buildings to be based on the open protocol, native BACnet

The controls must be open protocol allowing multi-vendor integration. It must be future compatible for further expansions.

What does this all mean? To the average facility manager, the above statements mean that they will receive a system that is fully open and allowing easy integration and future expansion without having to remove the existing system. Facility managers are excited about the prospect of having full control over their BAS without relying on external contractors to perform part of their duty. No more reliance on one vendor and no more expensive contracts. If a controller fails, the facility manager has the flexibility to choose another vendor. It can be argued that all these statements are valid but there are hidden truths that the facility managers need to be aware of.

  1. Interoperable, not interchangeable: The fundamental concept many people in the BAS industry misunderstand is that they believe that open protocol implies that if a controller fails from one vendor, they can replace it with another vendor. It is true, but it is not as simple as removing the faulty device from the network and plugging in the new controller. There are overhead vendor dependent software tools that must be used to configure and program the controller before connecting to the network. It is not as simple as plug and play. Therefore, there are extra costs associated with changing to another vendor.

  2. Programming is proprietary: The open protocol standards (BACnet or LonWorks) do not define a standard programming language or rules to program an application controller. The BAS equipment manufacturers have similar styles of programming environment, either text or graphical based, but the actual interpretation of the code written by the user is proprietary to each vendor. Therefore, programming the controller is always vendor dependent. For example you cannot use Vendor A BACnet software to program a Vendor B controller.

  3. Programs not visible to end user: It is clear that programming is vendor dependent, but it should be visible to the end user using the vendor dependent software. The facility manager has the right to view the programs that are controlling the buildings and if required to modify without depending on external parties. However in a lot of cases, the manufacturer and/or the system integrator will not allow the facility manager to view the programs. If a program change is required, the facility manager must contact the system integrator to make the change. The program change is completed by the system integrator with a special plug in tool. It is clear that the system integrator is using post-installation service as a cash cow for his business but it is simply wrong. I have consulted many facility managers who cannot change or view their programs without the involvement of external parties and for this have to allocate a large portion of their budget. In one case, a large medical research and development site made a decision to remove the BAS from a vendor and change it to another vendor that allowed full open view of the system.

  4. Not everything is open: A BAS device can claim it complies with an open standard. What does this exactly mean? Many take this for granted and assume all features in the device comply with the open standard. The standards do not imply that all features in the device must be open. It only states that if the device implements a feature that is covered by the standard, it must comply to a strict set of rules. Therefore a device can have its input/output points readable and writable via an open standard, but other features such as scheduling, alarming and data sharing can be proprietary. The facility managers generally only discover these issues a few years after installation when attempting to integrate with other devices. Therefore, it is critically important that stakeholders of the building understand the standard conformance statement of the open device. BACnet has a document called the Protocol Implementation Conformance (PIC) Statement. This defines all features supported by the device to the standard. It’s a detailed document outlining the device implementation for its application, network and data link layers. Generally, only personnel with a deep understanding of BACnet are aware of this document. The average facility manager does not know of the existence of the document, yet alone to try to understand what is included. Understanding and interpreting the document is a must for all stakeholders. No controls product should be approved for a project without the consultant in charge reviewing the documents. By following this simple process it can save lots of money for the facility in the future. Education is the key to achieving better understanding of the document. We as an industry must begin to circulate more information about these documents to open forums.

  5. Too many gateways: The fastest method to open the standard market for a BAS manufacturer that has a well designed proprietary system is to implement a gateway to convert the proprietary protocol to the open standard. It is a valid solution and works well in most situations. However, in terms of scalability and having a distributed open solution, it simply fails. Having an open system that is fully distributed will allow the end user to access data directly from the source without the reliance on other devices. Another fallback is that if the gateway fails, the user does not have access to the entire system. Also, in many gateway designs the manufacturer only supports minimum open standard features, just to expose their proprietary data. The key to remember with gateways is that it will work but it can have limitations in future expansions.

  6. Open web environment: Just like moving to the open protocol standard, moving to the open web standard for a BAS manufacturer is to implement a gateway like a service in the software to import the generated graphics and the live data to a web page. Is this a truly open web BAS system? No. What can you the end user do with the web page? The end user can monitor the data and change set points. Can they edit graphics or modify a program or change trend logging setting? In most cases no. The end user must use a separate desktop application to complete these advanced feature setups, making the task tedious and long winded. A true open web environment should allow the user to complete all tasks from engineering, commissioning and facility maintenance using a simple web browser. Therefore, the stakeholders of the building need to investigate what data can be viewed via the web interface and what you can do with the data through the web interface. Do not assume that everything can be done through web interface when the specification of controls products states it is driven by a web interface.

Control Solutions, Inc The key to uncovering the hidden truths about open systems and to save money in the future is for the stakeholders to ask the right questions before the product is installed. Following are some of the questions that must be clarified before proceeding, even if the system is specified to be open.

  1. Will the end user be able to monitor and change programs?

  2. Will the end user be able to access and view all features of the BAS via web interface?

  3. Will the end user be interfacing to the system via a gateway? If so, what limitations does it have in terms of supporting all open standard features?

  4. What features of the system are proprietary?

  5. How scalable and distributive is the system? Is the system relying on a certain device which controls many features? If so, what is the implication to the system on failure of such device?

  6. What are the implications to the system with future expansions with same or different vendor?

  7. Will the system be backwards compatible with future open standard changes?

  8. What is stated in the conformance statements?

‘Open’ standards is simply a great phenomenon for technological evolution. It generates a plethora of business opportunities for both vertical and horizontal industries, as long as the key stakeholders understand the intricacies of the open standard. Ask the questions early to save many dollars in the future. Do not assume the word ‘open’ means everything.

footer

Lynxspring
[Click Banner To Learn More]

[Home Page]  [The Automator]  [About]  [Subscribe ]  [Contact Us]

Events

Want Ads

Our Sponsors

Resources