European Process Automation Users discuss ‘Electronic Marshalling’ at Emerson Conference
06 December 2010
Introduced one year ago, the ‘I/O on Demand’ concept is still under discussion, and a few end users have decided to introduce pilot projects to test the technology. They reported their first experiences at a conference in Berlin.
Franck Jouault, Systems Department Manager at Solvay in Tavaux, France.
Electronic marshalling is perhaps the most talked about feature of Emerson’s I/O concept introduced in 2009.
The approach is said to eliminate two-thirds of the wiring and connections needed by today’s conventional marshalling cabinets. The key technology ingredient is a single channel module named the CHARacterisation ModuleS (CHARMS).
CHARMS relay I/O information to a DeltaV controller via an Ethernet backbone. The electronic method eliminates the need for users to wire I/O to specific controller I/O cards, yet provides single channel integrity and flexibility down to the channel (not I/O card) level. This makes projects simpler and easier to engineer and implement.
Peter Zornio, Emerson Process Management’s chief strategic officer says another significant benefit from electronic marshalling is dealing with change.
“Whereas traditional project engineering requires major time and cost in changing rack-room I/O wiring and terminations, as process design is refined during project execution and construction, electronic marshalling makes changes easy and eliminates re-wiring.
“Simply terminate the field wires, insert the CHARM and electronically marshal the signals. It dramatically simplifies the I/O and marshalling design process.”
All the CHARM modules are identical. An engineer can carry a pocket full of spares.
Estimates at Fluor
Vincent Grindlay, Fluor Supply Chain Solutions, spoke about a study conducted by Fluor and Emerson Process Management on the Electronic Marshalling system on an integrated gas project. The study compared real data from a recently commissioned “traditional” project, with a theoretical project that was identical except for the use of Electronic Marshalling and CHARMs technology. The real project used Emerson’s DeltaV digital control system v10, along with a traditional engineering approach.
Fluor’s part of the project was to provide engineering, procurement and construction support services. Emerson’s scope covered 80% of the automation and safety systems.
Mr. Grindlay described the problem with keeping the engineering contractor and automation supplier together on the project. “The traditional way of selecting an automation supplier in a competitive bid environment, is for the engineering contractor to develop sufficient information to define the basic automation scope and allow for a technical and commercial evaluation. However, during the process of selection, the Engineering Contractor is moving forward with further design developments. Therefore by the time the automation supplier has been selected, the automation scope has changed – introducing variability. This occurs because the two parties are, in effect, working on different sets of information. To align both the Engineering Contractor and the automation supplier, it is common to introduce a design freeze which allows the systems supplier, in this case Emerson, to ‘catch up’ with the changes that have been incorporated in to the design.”
With 'modification packs' the project slips
Life in the construction and automation industries would be pleasant if it were not for the so called modification packs, or “modpacks” as they are known in the industry. These are the fly in the ointment, the irritating engineering changes that cause disruptions for virtually everyone working on the system.
Modpacks are produced by the engineering contractor as he progresses with the project and gains a better idea of what he wants as an end result. It summarises the additions, deletions and any other changes from the base scope. As the information is applied, cost and schedule are affected. For example, in this particular project, said Mr. Grindlay, the effect of the first Modification Pack, (they are numbered ModPack1, ModPack2…) which was predominately design development and engineering, was for the project to slip by one month.
ModPack1 was bad, but ModPack2 was even worse. “The project’s mechanical packages are notorious for their long lead times,” he said. “As a consequence, by the time these were understood, the project had moved along again. This new information needed to be shared with the systems supplier, so a second Modification Pack was issued that included all the mechanical package automation information.
“However, by the time this pack was issued and implemented, there was no slack left in the schedule to allow for hardware and combined tests,” he said. “Consequently it introduced a seven month delay into the schedule.”
So, what could electronic marshalling have done?
A good part of these project delays could have been avoided if Fluor had used electronic marshalling instead of traditional wiring, says Mr. Grindlay. And it would have been less expensive.
Using traditional work practices, as was done on this particular project, any change to design requires cabling changes, which in turn requires reworking and rewiring. Additional time has to be allocated to the project in order to accomplish this. Electronic marshalling, on the other hand removes the need for physical changes when the design moves – its generic electronic modules allow the project teams to work more efficiently.
“On this project, using Emerson’s Electronic Marshalling would have removed the need for the first Modification Pack as the changes required would have been part of normal design development,” says Mr. Grindlay. “Also, the changes required by the mechanical Modification Pack (ModPack2) would have been greatly simplified - allowing them to be implemented in about half the time.
“Overall there would have been a cost reduction of 80% for Pack 1 and 45% for Pack 2. In addition, these benefits mean that the overall project schedule would slip by just two months, rather than seven months using traditional methods,” he said.
The total savings would have been an estimated 1.43m euros, or around 10% of the cost of the total automation package, and would have brought forward the delivery of the project by four months. The savings are predominately in the engineering costs and not in hardware or software costs.
Trials at Solvay
Franck Jouault, Systems Department Manager at Solvay in France, outlined his experience with electronic marshalling. He said Solvay decided to deploy the technology on two projects. The first was a modernisation of the automation system of its pilot plastics processing plant. The system consists of one controller with 200 CHARMS I/O.
With CHARMS, Solvay eliminated the marshalling cabinet and the associated wiring and design entirely, as well as the terminal junction box. Cables now route directly from junction boxes in the field to the CHARMS cabinets.
The DeltaV Version 11 system and CHARMS greatly simplified the management of change, said Mr. Jouault. Previously, Solvay added an extra 5 per cent on their I/O requirements because of change orders, wrong estimations, and other problems. With CHARMS, the definition of the I/O was the same throughout the project.
The next Solvay project
Mr. Jouault says Solvay Tavaux is now planning to deploy DeltaV Version 11 in its critical IXOL production processes. IXOL is a rigid flame retardant polyurethane foam used in construction applications. The current system controlling the process has around 1,300 I/O, including the safety instrumented system. The unit is scheduled for start-up in March of 2011.
There is not much space in the control rooms, so the space-saving ability of electronic marshalling will be a benefit. The new system must be installed in parallel with the old system until the old system can be decommissioned and the company wants to minimise downtime to just two weeks. The first week of the project is usually dedicated to the wiring and related tasks, with the second week dedicated to FAT and SAT. Using CHARMS and electronic marshalling, engineering work is simplified, including the cabinet design, I/O design, wiring diagrams, and the wiring work itself.
The Perstorp migration project
Perstorp Specialty Chemicals AB says it will replace its existing Emerson RS3 distributed control system at its pentaerythritol processing plant in Perstorp, Sweden. The existing system has controlled the manufacture of the paint and lubricant additive for 26 years but managers say they now need to run the plant’s batch operations continuously and must plan for the time when spares for the existing system will no longer be available.
Jörgen Annell, Engineering Manager at Perstorp, says that electronic marshalling will help minimise installation time and costly plant downtime during the upgrade because it removes the need to wire I/O to specific controller I/O cards. This alone eliminates up to two-thirds of the wiring and connections needed by conventional marshalling cabinets.
Mr. Annell said his company will deploy 792 single channel Characterization Modules (CHARMS) and 60 DeltaV S-series I/O modules to relay 3,000 Device Signal Tags.
This unique wiring technology is expected to reduce downtime during this upgrade by two days, helping to reduce lost production. The migration procedure will be performed by Perstorp’s engineering team and is expected to take two weeks to complete.
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