ExxonMobil saves time with automated device commissioning

“Where it used to take two technicians about an hour, ADC execution is presently about 5 minutes.” ExxonMobil’s Erik Phelps explained the dramatic time savings realized through the automatic device commissioning, or ADC, of HART devices facilitated by Honeywell Process Solutions’ Universal I/O capabilities. 

Time is famous as the most precious resource because us mortals can never get it back. So it’s rare when we get a chance to save huge amounts of it. That’s what automation is all about, of course, and it’s especially beneficial if you’ve got thousands of control loops to commission, check and maintain.

Similar to most process facilities, this was the challenge faced by operators and engineers at Gulf Coast Growth Ventures’ plastics plant near Corpus Christi, Texas. A joint venture between ExxonMobil and SABIC, the company operates and maintains about 10,000 loops at this facility that produces mostly polyethylene, which it began upgrading in 2015 to Universal I/O from Honeywell Process Solutions.

“In a traditional loop check, a handpump is used to simulate process conditions, while a transmitter outputs a 4-20 mA DC current that’s proportional to the simulated pressure,” explained Erik Phelps, principal instrumentation, measurement and control systems (IMCS) engineer, ExxonMobil. “Either way, loop checking is time-consuming. HART doesn’t need a handpump for simulation, but both still need physical and visual verification. We usually need two technicians in the field, and budget about one hour per instrument, though more time may be needed for set up and permitting.”

But with Universal I/O from Honeywell Process Solutions, users can now simply “pair up and validate,” said Matt Willmott, technical manager, projects and automation solutions, Honeywell Process Solutions. “This is how Experion, Universal I/O and smart instruments can enable automated device commissioning (ADC) and transform project delivery,” he said. “For example, standard remote cabinet builds can now accommodate more late-binding of field designs, use testing methods built into the platform, have a dedicated HART modem per I/O channel, and be installed way before shipping and installation.

Willmott and Phelps presented “ADC for Greater Efficiency” this week at Honeywell User Group Americas 2022 in Orlando, Fla.

Verification grows up

To alleviate manual loop-checking tasks, Phelps reported that many ADC verification functions have been automated, and presently include eight or nine basic checks. They include:

• Instrument communication and diagnostics;
• Smart junction box (SJB) channel matches to the process control system (PCS);
• Instrument tag matches to the PCS;
• Engineering units/range matches to the PCS;
• Auto instrument linearity, with a nine-point of ascending and descending percentages, PC high/low alarm setpoints, and a three-point assisted graphics check;
• Analog output (AO) assisted stroke failure mode;
• Digital output (DO)/digital input (DI) assisted stroke, with on/off valve limit switches and stroke time capture; and,
• Auto data capture for the loop check report.

“One of the main benefits of ADC is field time savings. Where it used to take two technicians about an hour, ADC execution is presently about 5 minutes,” said Phelps. “ADC also identifies instrument diagnostic errors, and reduces errors for automated data capture and test records and makes data capture more consistent.”

Phelps added the limits of ADC are that it needs HART version 6/7 instruments for full functionality because HART 5 has limited automated testing, and the most field time savings are with the automated linearity checks on transmitters. Prerequisites for ADC include: EPCs must provide instrument device data to Honeywell; hardware customers must configure ADC for each tag; and instrument suppliers must make sure they don’t make late changes to the HART revision.

As of last December, Phelps reported that GCGV’s plastics plant has migrated about one third of its loops. “In our experience, we found that we could do ADC on more than 30% of our safety instrumented system (SIS) loops,” he said. “It’s available now with higher releases of Experion. However, critical instruments still need hand pumping to verify sensors. We can also precheck loops with ADC to find big errors, and then hand pump later. We’re considering eliminating hand pumping of less-critical SIS instruments.”

Meanwhile, more than 15% of GCGV’s PLC loops aren’t available for ADC. Consequently, the organization is investigating if a HART multiplexer could interface ADC with its PLC loops, though moving more control from PLCs to the PCS could introduce other interface issues.

“We also found that 15% of ADC-related loops have devices that aren’t compatible with HART, such as specialty flowmeters, vibration and axial instruments, discrete on/off devices, and analyzers,” said Phelps. “Still, we think we have an opportunity to move from doing ADC on 30% of our loops to doing it on 90% of them.”