The always-on nature of cellular wireless communications and cloud-based networking provides real-time connectivity and boosts control-system efficiency.
By Vishal Prakash, product manager, ProSoft Technology
Editor's Note: This article is adapted from a white paper, "Top factors to consider for remote connectivity to your Connected Enterprise in the cellular age." Download the free, full white paper to get in-depth explanations of the six factors that affect remote connectivity — security, system expansion, maintenance, remote access, the Connected Enterprise and simplicity. Also learn how advances in cellular technology and the cloud are affecting how users can optimize control systems.
The concept of monitoring remote industrial infrastructure assets began in the 1970s. Since then, the types of communications media used to monitor the remote assets have come a long way — from trunk mobile radio (TMR) to today’s different types of cellular wireless local area network (WLAN) communications.
Cellular communications for machine-to-machine-type applications was first introduced in the early 2000s. Over the last decade, cellular wireless communication has become ubiquitous and now is the primary form of communications for more than 75% of the world’s population.
A simple analogy for cloud-based networking is taking the Ethernet switch on your desk and placing it in the cloud. Devices connected to this switch can communicate with each other — a streamlined extension of your Connected Enterprise.
A more complete definition is that cloud-based networking exists and operates within a cloud environment/infrastructure. The infrastructure, resources, cloud network management, monitoring, maintenance, and other network administrative and operational processes are performed within or through the cloud.
So, should everyone with responsibility for a remote control and monitoring system adopt cellular communications? The answer is not a simple yes or no. You have to consider multiple factors before making the decision:
- Is the current system secure and adaptable to cloud technologies?
- Can the system be expanded easily?
- What about short-term and long-term maintenance costs?
- Is there remote access for diagnostics?
- Can your current system handle the increased data requirements to help ensure operational efficiency?
The answers to these questions will be different for each use case. Let’s look at this differently: Does today’s cellular wireless connectivity solve problems so that you can continue to operate your system easily, reliably and securely, and meet all of your key performance indicators (KPIs)?
Consider these six factors to select cellular wireless communications for remote connectivity.
Security is not a one-step approach, such as using usernames and passwords for login. Control-system security must take a holistic, multi-layered approach, called Defense in Depth (DiD). The DiD technique implies that:
- No single product, technology, or method is fully secure — it has to be a complete solution.
- The solution must address internal and external threats.
- The solution must use physical, procedural and electronic means at separate Industrial Automation and Control Systems (IACS) levels.
These are the layers that need to be secured:
- The cellular wireless gateway, because this is the point of connectivity to the control system.
- The network, which includes switches, routers, and firewalls. The network doesn’t apply if using a cellular gateway in the connected network.
- The Internet or the type of access for secure remote connection — for example, an OpenVPN server or a cloud service.
- The PC or a master PAC, which is the device that is used to connect to the remote asset.
- Procedure, which is a combination of security and safety for remote connectivity. Ensure that the right procedures to authorize, enable and disable connectivity are written, understood and enacted within the organization.
Any system can be expanded. But is it simple and cost-effective?
Consider a system that’s using typical licensed or unlicensed data radio communication — to expand, you might have to conduct a radio survey and add a radio-frequency (RF) tower, a repeater site, or store and forward through an existing site. Any of these activities can be expensive and complex.
If the system uses cellular communications, expansion is simple — add a cellular modem to the new site(s), activate the modem and connect it to the network.
All systems will require some sort of maintenance to help ensure longevity and smooth operation. Maintenance for cellular systems is minimal, limited to low-profile antennas and possibly some RF cable, significantly reducing OpEx costs.
With older systems featuring data radios or leased line, remote access was complex to set up and maintain. Remote access to the PAC required the remote user to connect to a central location, and then access the PAC. The same is true with leased line or fiber-optic setups.
A cellular-based wireless remote infrastructure network provides anytime, anywhere secure remote access, direct to the PAC. This direct connection means the system operates uninterrupted, with increased speed and bandwidth.
It’s no longer acceptable to just bring back status information from a remote site. Control systems and smart field devices can provide a plethora of information such as operation parameters, advanced diagnostic data, time-stamped data, asset identification data and performance data. This information is useful in analyzing the overall process efficiency, and potentially making improvements to your Connected Enterprise in real time. To process all of this data efficiently, a high-speed connection and increased bandwidth will be required.
Simplicity should be a factor. It should be measured in the connection and recovery time of the gateway, ease of installation, support and compatibility.
ProSoft Technology, Inc., Bakersfield, California, is a participating EncompassTM Product Partner in the Rockwell Automation PartnerNetworkTM program. ProSoft offers communication modules and network solutions that include in-chassis, protocol interface products, in-rack flow computers and PCs, stand-alone gateways and wireless communication networks.
The Journal From Rockwell Automation and Our PartnerNetwork™ is published by Putman Media, Inc.