CBAS and The Internet

When Computrols introduced its line of Internet Controllers, it opened up a whole new way for people to communicate with controllers and automation systems. With that came a lot of confusion about what can and can’t be done in regards to remote access to controllers and whole CBAS systems. Let’s see if we can clear up some of the confusion by going through the different scenarios.

pcAnywhere Dial-up

In the beginning, there was pcAnywhere, the Symantec software that allows you to access and control another PC, either over a LAN (Local Area Network) or WAN (Wide Area Network or Internet). PcAnywhere works with dial-up using a standard telephone line, and is still used in many buildings that don’t have the budget to upgrade to some form of high-speed Internet. The same phone line can be used by CBAS to dial out and send alarms to pagers. Then, the engineer receives the page and can dial in to the system and make adjustments.

pcAnywhere High-speed

Many buildings have made the switch to high speed Internet, often because the engineers have Cable or DSL at home. It isn’t possible for them to use high speed Internet to get into a dial-up system. But, it is possible to dial up to the Internet and get access to a high-speed system. Anyway, pcAnywhere is a whole lot better when you have high-speed on both ends. Computrols has replaced the use of pcAnywhere with Log-Me-In. Go to www.logmein.com for more information.

Graphic Workstation (GW)

The same connectivity concepts apply to a CBAS GW over the Internet, and in most cases, works faster than pcAnywhere. The other benefit to GW is that it is less of a security risk if the CBAS DPU is on a LAN with other computers. When you gain access with pcAnywhere, you get access to everything on the computer, including access to other programs and other computers on the network. Many network administrators don’t allow pcAnywhere on their LANs because of this. With GW, you only gain access to the CBAS database, so there’s no security risk. So, engineers and technicians can be at home, at another building, or in a cyber café, and get access when they get a call, page, or email alarm.

Email Alarms

Another benefit of high-speed Internet is that you can program Email Alarms on any point that has an alarm programmed already. Emails can be sent to a dispatcher, people at home, or to a text-message-capable phone.

Controller Web Pages

Although this feature isn’t extensively used, you can access a web page on the Internet Controller itself. The web page can be set to require the user to log in to gain access. From there you have a choice of Text View or Hardware view, and command-able points can be commanded. However, the point program screen is not accessible, so schedules or logic cannot be changed.

CBAS-Web Server

Now that we’ve covered the basics, let’s get into some more unusual or complex situations. First, there’s the CBAS-Web Server. This product allows engineers and tenants to schedule overtime for their AHU by accessing a web page. A separate computer next to the DPU serves the web page. The web page is exposed to the Internet by forwarding a single TCP/IP port from the public (WAN) side of the router to the Overtime Web Server.

Stand-Alone Controllers

Stand-alone controller access is another possibility using the Internet. Let’s say you have a small building requiring only one 32-point controller, and the occupants of the building have a LAN with Internet access. That controller could be placed on the LAN by running a network wire from the controller to a nearby switch that is part of the network. Then, one port needs to be forwarded from the router to the controller. The technician would have the database for that controller in CBAS on his office computer or laptop. In that database, the IP address of the controller would be the IP address of the router, and the router would forward communications to the controller. Also, that database could contain a channel of RS RS-485 controllers like VAVs, or a Modbus RTU channel for some Veris Hawkeye power meters.

Multiple Stand-Alone

Let’s say you have a building management company that manages several small buildings that require one Internet controller with up to 64 hardware points and maybe a few more controllers or VAVs. Probably the best way to handle this situation would be to have the DPU at the management office and allow GW access from the outside by forwarding one port on the router. Business DSL or cable access with a static IP address would be preferable at each location, allowing the DPU to have a database containing a controller from each, connecting in the same way described in the previous paragraph. If more controllers are needed at a particular location, they could be placed on the RS RS-485 channel hosted by the one Internet controller.

People at the management office could monitor the building from there, but what happens when a technician is needed at the site? A permanent workstation could be placed at the remote building or, the technician brings a laptop, plugs his cable into the router or a switch on the LAN, and connects as a GW.

Multiple DPUs

On the other hand, you could have a DPU at each of the management company’s buildings and a workstation at the main office. However, this would not be a viable solution logistically or financially unless they have four buildings or less. A CBAS Commercial license would be required at each location, as opposed to one Professional license in the previous example. To connect from the main office, the user would have to connect as a GW separately to each building, one at a time. Unless the user was connected at the time, he would not see alarms as they occur.

WorldSTAT Enterprise

Let’s say a management company has 100 or more sites in many cities, maybe across multiple time zones. With a WorldSTAT or other Internet Controller in each location, and a DPU in the corporate headquarters, WorldSTAT Enterprise software would give them the features they need to achieve rapid deployment of new locations and regional management.

While these are just a few of the scenarios that are possible with Internet controllers and CBAS software, they cover the main concepts necessary to understand connectivity.

Example Diagram

Below is an example of one way to connect buildings over the Internet. It shows a management company that manages three buildings from its office using one CBAS Automation Server and one TCP/IP controller in each building. A laptop can be connected to the network in any building and log on as a workstation to the Server in the main office.