The supplier then markets this cloud-based, remote-access SaaS to customers, charging a monthly fee for use, which is typically based on the number of nodes and the amount of data that goes through their cloud. The advantage to end users is that they only need to provide connectivity to the cloud from each remote site, with all other data communication infrastructure provided by the supplier for a monthly fee.
SoftPLC's TagWell is a good example. "TagWell is a cloud-based, bi-directional portal to SoftPLC remotes, which uses an application platform interface (API) to allow customers to perform remote management of their process automation systems," explains Cindy Hollenbeck, vice president of SoftPLC (Figure 1).
"SoftPLC remotes can be gateways to existing equipment, or they can be a PAC and gateway. With the API, applications that run in TagWell can read/write to the tags in any remote," adds Hollenbeck. When the remote is a gateway, any vendor's automation system can be used, as long as it can communicate to the gateway. In other cases, the SoftPLC remote is the main controller for the application as well as for the gateway.
"The entire architecture is designed to minimize bandwidth use to cut costs for cellular or other costly communication network interfaces for remote systems such as satellite, but it can also work on hard-wired Ethernet connections. The remote can be programmed to report only by exception to further reduce bandwidth requirements," notes Hollenbeck.
One SoftPLC customer uses TagWell for monitoring chemical tank levels. Each tank is equipped with an embedded SoftPLC RTU that measures level. The level is reported to TagWell where all the tanks can be viewed in a browser optimized for viewing on a smart phone. TagWell also provides the tank level information to the customer's SCADA system once per day, and immediately reports refill alarms, so the logistics system can schedule deliveries. Critical low-level alarms are sent to the SCADA system and as text messages.
Vipond Controls is a system integrator in Calgary, Alberta, Canada, that provides a hybrid, cloud-based, SCADA SaaS solution based on InduSoft's Web Studio software to its customers in the oil and gas industry. Vipond customers use its cloud-based remote access solution instead of purchasing and installing SCADA software and hardware at each remote site.
A typical installation consists of one or more controllers and/or RTUs at a remote production site, such as an oil well, explains Darryl Vipond, president of Vipond Controls. Each of these local devices is connected to Vipond's cloud-based iSCADA via radio, cellular or satellite connections. No SCADA hardware or software is required at the site because iSCADA provides this function remotely.
Once the data is uploaded to the iSCADA application in the cloud, it's available for remote access. "A key feature of iSCADA is very fast response rates, which enable us to deliver a remote HMI experience in near-real time," Vipond says. "This remote viewing can be delivered through any web browser, a PC set up as a thin client, or a smart phone such as the iPhone and certain Android phones."
Vipond adds, "Our SCADA solution creates a unique experience for each client by using a hybrid cloud. With iSCADA, each customer has their own virtual machine running within Vipond's server cloud. All data is kept safe and independent of other machines running in the cloud." (Figure 2)
Remote asset management is another process application that fits well with the SaaS model (Cloud-Based Asset Management). Remote access and asset management are public cloud services, but private clouds are perhaps the most widespread implementation in process industry end user firms.
Private Cloud Savings
Process industry firms are very concerned with protecting their automation and information systems from cyber attacks. They also demand nearly 100% uptime, and are leery of cloud implementations that require an Internet connection, so private clouds often make the most sense for process automation applications.
A certain major pulp and paper company uses virtual machines in a private cloud to host the application software for the distributed control systems (DCSs) in some of its largest manufacturing facilities. Besides running the main application programs, it uses the cloud to host thin-client HMI stations for its operators.
In its largest private cloud implementation, it is using VMware. VMware provides a set of software tools that help users virtualize PCs to run multiple operating systems on one machine.