ARC Closer Look at I/O on Demand - Emerson Automation Experts

ARC Closer Look at I/O on Demand

Emerson’s DeltaV team connected with ARC Advisory Group’s Larry O’Brien to share details on the DeltaV I/O on Demand capability in the upcoming DeltaV version 11 release. Larry’s ARC View, How Emerson’s “I/O on Demand” Is Changing the Automation Infrastructure, summarizes the I/O on Demand concept as it applies to Electronic Marshalling, Foundation fieldbus, WirelessHART I/O, and safety instrumented system I/O.

In the whitepaper, the issue for process manufacturers is framed:

A lot of wiring in place today in process plants probably doesn’t need to be. The potential for reducing this wiring, I/O, and other hardware components and the labor costs associated with it is tremendous.

For those not familiar with the phrase, the last mile (or last kilometer), it’s the final hop of the communications path to end customers. Many think of it in terms of the phone/cable TV/internet service to residential dwellings. The sheer number of connections of “the last mile/kilometer” slows upgrading communications bandwidth.

The whitepaper ties this concept to process manufacturing plants:

I/O represents the “last mile” from the automation system to the field device, and users look for any opportunity to reduce the cost of this last mile and provide better diagnostics to avoid failure.

Electronic Marshalling takes the practice of marshalling and its connections with multi-channel I/O to a single channel:

…users add I/O as they need it, one point at a time. This is done with CHARacterization Modules, or CHARMs. CHARMs turn the idea of conventional I/O on its head.

Instead of conventional wiring landing at a terminal block, wired to I/O modules, which are then wired to controllers – the wiring is connected directly to a DeltaV electronic marshaling rack. CHARM modules are attached onto this continuous rail. CHARMs can then be characterized however you want them to be and plugged into the rack. CHARMs also have self-diagnostic capabilities.

This approach eliminates the need for separate marshalling cabinets, which can reduce the number of control room cabinets by 50% and reduce intra-cabinet wiring by 90%. Most project engineers know the pain associated with late project changes, which often leads to rewiring, re-terminations, control strategy I/O binding changes, etc. These thoughts are summarized:

In ARC’s view, the significant cost associated with traditional marshalling methods can limit the changes possible in the engineering and design of the system. The new I/O on Demand capability of Emerson’s DeltaV S-series allows users to add or change I/O types whenever they make project design changes, no matter where the I/O is located. This reduces project costs and, even more importantly, reduces time to startup.

The whitepaper highlights the integrated power supply in the DeltaV Foundation fieldbus card, which eliminates bulk power supplies and fieldbus power conditioning modules. This again, eliminates cabinets and it also adds diagnostic coverage of these power elements from the DeltaV system.

With wireless control applications emerging, redundancy options have been added:

Redundant items include DeltaV network communication, 24VDC power, I/O cards, remote links, and the multiple communication paths of the adaptive mesh network itself. The redundant architecture eliminates any single point of failure and provides immediate switchover in case of a fault.

From a safety instrumented system I/O perspective, the DeltaV SIS has:

…a modular logic solver that has integrated I/O processing, memory and logic solver processing… added every time I/O is added to the system.

This 7-page whitepaper provides a great overview of the elements of I/O on Demand and how it can change the economics of a project. As mentioned in an earlier post, additional whitepapers delve into Electronic Marshalling and an economic cost analysis in more detail.

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Update: I’ve updated the link to the whitepaper which is now additionally hosted on the web site.

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