PLC vs Controller

7/30/2019 PLC vs Controller

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cmpaave vevew What is the best way to manage a diesel or gas genset application? This comparative overview

shows how PLC solutions compare to dedicated purpose controller based systems.

Application expertise

PLC The PLC’s weak point is its single processor as your production may come to a

standstill should it ail.

Controller DEIF controllers utilise distributed processing: each genset, tie breaker and

mains breaker has its own dedicated processors executing their own unctions

and monitoring the overall power plant. No single processor is in total control

o the entire system. Optional redundant communications paths prevent single

point ailures rom causing a blackout. This way, we ensure that your power plant

remains ully operational at all times.

Flexibility

PLC Flexibility is one o the PLC’s biggest advantages but also a great Achilles heel.

With exibility comes the responsibility or the entire system operation. One

small change in a given unction can cause unoreseen problems later. Even the

smallest change can result in signifcant re-testing.

Controller With Dedicated Purpose Controllers, the application sotware has been proven

through thousands o running hours in multiple applications worldwide. Each

application change is taken very seriously and tested thoroughly prior to release.

The utility sotware allows the user to view and edit all parameters. The parameter

fles can be copied to share best practices between gensets and/or applications.

In order to prevent tampering, the fles can be password protected.

Design consistency

PLC As PLCs are general purpose devices, they are oten confgured dierently each

time. Each system needs to be studied and learned rom the ground up every

time. Saety and reliability can be compromised when workers need to maintain

or troubleshoot unamiliar wiring and sotware.

Controller Dedicated Purpose Controllers like the AGC-200 have terminals with specifc

unctions printed on large, easy to read, labels. This makes it saer and much

easier or installation and service personnel to work on the system, reducing

errors and preventing damage due to handling or wiring errors.

Protective relay functions

PLC PLCs are sequential processors. Both control and protection unctions arescheduled and carried out in an explicit order. During the control process

protection is inactive, causing undesirable delay to critical protective unctions.

Such delay may result in unnecessary damage to critical components.

Controller Speed is o the essence when protecting electrical systems. Delays in protective

unctions can lead to excessive equipment damage. Each circuit breaker

(generator, tie, and mains) is monitored by an individual processor. Watch dog

timers ensure protective unctions are executed on a timely and efcient basis.

Fast response means minimal damage and minimal system disturbance ater

a ault. DEIF utilises state-o-the-art automatic test equipment to thoroughly

simulate all types o grid and system aults to ensure proper operation beore

each product release.

A DEIF controller after a climate chamber test

below -40°C.



PLc nlle?

Advanced power management

PLC Each unction needs to be programmed every time. The programmer’s personal

preerences can result in inconsistencies between applications andnew learning curves or each installation. The cost to add more unctions can be

disproportionately high.

Controller Advanced power management unctions, like load shed/load add, uel

optimisation, sot load/unload are already programmed, tested and proven.

Adding unctions can be done with minimal cost and known results.

Engine communications

PLC Connecting PLCs to various engines can be very time consuming and difcult.

Engine manuacturers interpret the J1939 standard dierently. Even engines rom

the same manuacturer change over time. Pulling this data can be timely and

require extensive programming, all o which may need to be re-done i the engine

changes.

Controller Our dedicated engine communications team monitors leading engine

manuacturers and continuously keeps DEIF controllers up-to-date with most

electronic engines. This contributes to DEIF being the world expert within engine

communications.

Documentation, customer service and support

PLC The documentation or a PLC is as custom as the PLC itsel. Maintaining

such custom documentation oten alls to the end user. Features added later

require the documentation to be updated, which is a time-consuming task.

PLC vendors oten rely on just a ew key employees to do the programming,

service and support or their customers. This can cause complications inthe subsequent programming and urther development o the system.

Ater commissioning, only the PLC programmer will know the ull details,

potentially limiting the inormation and your service options to that person or

team. Support can be delayed, expensive and maybe even impossible.

Controller All documentation or DEIF controllers is available on the website or ree,

oten in multiple languages, with detailed explanations or each unction. DEIF

oers training, commissioning and ree phone support by dedicated engineers

in your local language and in your time zone. We are present in more than

30 countries, and with a large team o dedicated engineers, support is always

competent and close by.

Test

PLC Typically, a PLC ladder programme is made or a ew projects only. Oten, it

is tested during start-up by the programmer, inevitably extending the start-up

time or shortening the test. Oten, a change in one area will result in a dierent

problem in some other unction.

Controller DEIF frmware is made by committed programmers working exclusively on

power management. Extensive testing is done by dedicated technicians with

widespread knowledge about how the system works. Thousands o systems

are in use today worldwide. Hence, DEIF sotware is subject to ongoing strict,

systematic and extensive testing under natural conditions. Our constant and

intense ocus on quality makes DEIF units suitable or any operating environment

rom the extreme heat o India to the bitter cold o Alaska or Siberia.

Power in Control is not just a saying. It defnes the very essence o who we are and what we

do or you.



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DEIF A/S · Frisenborgvej 33 · DK-7800 Skive · Tel.: +45 9614 9614 · Fax: +45 9614 9615 · [email protected] · www.deif.com

Founded in 1933, DEIF has more than 75 years o experience. Today,

we are active on the international markets or engine & gen-set con-

trols, marine bridge instrumentation, switchboard instrumentation

and renewable energy controls.

It is our ambition to maintain and expand our position as one o the

most trusted suppliers within our elds o operation. This goal will

be reached by ensuring that DEIF continues to oer real competitive

advantages to our customers by supplying superior product quality, the

best and most fexible eatures and competitive pricing.

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PLC vs Controller