Key Note: Which Bus Goes Where?
The key note presentation will explain where in the plant bus technologies such as 4-20 mA/HART, FOUNDATION fieldbus, PROFIBUS are best suited. Those that build a plant today face several challenges: for instance, keeping the project on schedule and within budget. Plant automation must ensure tight product quality/yield (uniformity), high throughput, and great availability. At the same time cost of operation & maintenance must be kept low, as must cost of fuel and other utilities.
The key note explains:
- How fieldbus reduces wiring and I/O cost by a factor of 3 times or more signals per device, for an even greater overall installation savings.
- How "virtual marshalling" through soft-wiring simplifies design changes such as device type and count, signal count and type, etc., particularly with power built into the H1 interface card eliminating intermediate marshalling cabinets.
- About diagnostics from two-wire intelligent on/off valves integrating all devices, including electric actuators / motor operated valves (MOV), unsheltered gas chromatographs, and two-wire inventory tank gauging systems with intelligent device management software and predictive maintenance by eliminating proprietary protocols.
The number one problem faced by projects is installation. Issues include grounding, shielding, cable routing, insulation, and general workmanship of wiring and sealing. Experts will share lessons learnt, including the right installation techniques, the proper installation tools, right test equipment in sufficient quantity, and best practices for verification checks to ensure a successful project. Lots of real-life photo examples of do’s and don’ts will be shown.
Commissioning Issues and Solutions
The second biggest project issue is not having prepared the system for all the different types and revisions/versions of devices appearing on site.
Participants will learn:
• Best practices for device revision management to avoid surprises at commissioning
• Simple verification of the running network to prevent unexpected problems at startup
• To order devices with the tag pre-assigned from the factory for automatic commissioning
• Use express and batch configuration download
• There is no need for traditional five point loop check because there is no 4-20 mA
• All fieldbus devices including intelligent on/off valve, identify themselves by unique ID.
Project Execution Best Practices
Challenges with early fieldbus projects as far back as 15 years ago were very much related to technician’s unfamiliarity with software, downloads, and smart devices. Today, when most people, regardless of where they are in the world, have smart phones for which they download applications and media, and synchronize, this is no longer a problem. FF design eliminates engineering tasks such as I/O assignment and marshalling design, as well as field tasks like loop test and configuration check parameter by parameter, but apart from that project execution is not that different from hardwired systems.
Using Device Diagnostics in Maintenance Practices
A challenge faced by some plants is that use of device diagnostics has not been incorporated into daily maintenance practices; a shortcoming regardless of protocol used. Time-tested work processes were not re-written to utilize diagnostics. Moreover, device diagnostics was not sent to the right persons as maintenance work stations were located remotely, operator did not see device alarms. All device alerts had the same priority regardless of device criticality or fault severity. Cryptic error codes were displayed, without explanation of problem provided. No troubleshooting guidance provided and the important aspects were not highlighted.
Participants will learn:
- Provide access to device diagnostics from the operator station in CCR in three clicks or less.
- Classify and prioritize device diagnostics alarms to enable filtering for early warning routed to operators, while preventing alarm flooding.
- Re-write work processes around the device management software; troubleshoot and verify from the device management software first, before going to the field.
- Train operators and technicians on the device management software.
- Use devices that provide a clear diagnostic message that is easily understood, helps with the identification of the problem, provides guidance towards the correct action, and directs attention to the important aspects.
