Petromarsh delivers control system integration for oil, gas, power and process plants across the GCC and Europe. We join PLC, DCS, SCADA, RTU and HMI systems with emergency shutdown and fire and gas systems into one tested, documented plant. Our engineers design to IEC 61511, IEC 61131-3, ISA-101 and ISA-18.2, and prove it at FAT and on site.
Control system integration is the work of making many separate control products act as one plant. It covers the controllers, the operator screens, the networks between them, the safety systems that sit alongside, and the links up to the business. Done well, operators see one consistent picture and every trip works first time.
A rugged controller built for fast, discrete logic: motors, sequences, interlocks, packaged equipment. Scan times of a few milliseconds. Common on compressor skids, water treatment and machine control.
A plant-wide system where controllers, I/O, HMI, historian and engineering share one database. Built for continuous regulatory control with hundreds of PID loops, batch to ISA-88 and managed change.
Software that supervises assets spread over a wide area, such as pipelines, well pads and substations. It collects data and sends set points, while local controllers do the real-time control.
A low-power controller for remote sites. It talks to SCADA over radio, cellular or fibre using telecontrol protocols such as IEC 60870-5-104 or DNP3, with time-stamped event buffering when the link drops.
The operator screens. They range from a local panel on a skid to a full control room with large overview displays. Good HMI design is what lets one operator run a large plant safely.
Separate systems that take the plant to a safe state when a hazard develops. They are engineered to IEC 61511 with a target safety integrity level, and they must stay independent of the basic process control system.
The lines have blurred. Modern PLCs run hundreds of PID loops and modern DCS platforms handle fast logic. The choice now turns on scale, lifecycle and who will maintain it. A DCS suits a large continuous process where one engineering database and tight change control matter. A PLC with SCADA suits packaged units, utilities and widely spread assets. Most real sites have both, and the job of PLC DCS SCADA integration is to make them share tags, alarms, time and security rules without gaps.
We work across the main platforms, including Siemens PCS 7 and S7-400H, as well as Rockwell, Schneider, ABB, Emerson, Honeywell and Yokogawa systems. Our role is to design and deliver the integrated system, not to sell one vendor's box.
ISA-95, published internationally as IEC 62264, gives a common way to describe where each function lives. We use it to set boundaries, define interfaces and plan cyber security zones under IEC 62443.
| Level | What lives there | Typical time scale and interfaces |
|---|---|---|
| Level 4 | Business planning, ERP, logistics | Days and weeks. Kept outside the plant network, reached through a DMZ. |
| Level 3 | MES, historian, production reporting, alarm analysis | Hours and shifts. OPC UA (IEC 62541), SQL, MQTT via gateways. |
| Level 2 | SCADA, DCS operator stations, HMI, engineering workstations | Seconds to minutes. Client and server links, redundant servers. |
| Level 1 | PLCs, DCS controllers, RTUs, SIS logic solvers | Milliseconds. PROFINET, EtherNet/IP, Modbus TCP, IEC 61850 for substations. |
| Level 0 | Transmitters, analysers, valves, drives, detectors | Real time. 4 to 20 mA with HART, Foundation Fieldbus, PROFIBUS PA, IO-Link. |
Redundancy is only worth what the single points of failure you remove. We work through controllers, power, networks and I/O in turn.
On TenneT's 980 MW HVDC converter platform, built by McDermott at Jebel Ali in Dubai, we commissioned two redundant Siemens S7-400H systems. One ran integrated monitoring and control, the other the power management system. ET 200SP HA remote I/O connected over PROFINET on multimode fibre, with SCALANCE dual network access switches on PRP networks and redundant SITOP 24 V DC supplies. Every device carried an IEC 81346 reference designation, which made loop checks and fault tracing quick.
The emergency shutdown system and the fire and gas system are safety instrumented systems. They are specified, built and proven to IEC 61511 for the process sector, which draws on IEC 61508 for the hardware and software of the devices themselves.
| SIL | Average probability of failure on demand (low demand) | Risk reduction factor | Typical architecture |
|---|---|---|---|
| SIL 1 | 0.01 to 0.1 | 10 to 100 | Single sensor, certified logic solver, single valve |
| SIL 2 | 0.001 to 0.01 | 100 to 1,000 | 1oo2 or 2oo3 sensors, redundant final elements as the calculation requires |
| SIL 3 | 0.0001 to 0.001 | 1,000 to 10,000 | 2oo3 sensors, TUV-certified safety PLC, 1oo2 shutdown valves with partial stroke testing |
Trips the process on high pressure, high level, low flow and similar causes. Each trip is a safety instrumented function with its own SIL target from the LOPA or risk graph, set out in the safety requirements specification.
Flame detectors, point and open-path gas detectors, H2S detectors, smoke and heat detection, manual call points. Outputs start deluge, close fire dampers, raise beacons and initiate ESD or blowdown.
The cause and effect matrix maps every initiator to every action. It is the document operators, programmers and testers share, so we keep it tied to the code and test it line by line.
A single gas detector at its low set point, often 20% LEL, raises an alarm. Executive action such as isolation or deluge normally needs confirmation, for example two detectors in the same zone at high level (2ooN). This cuts spurious trips without delaying a real response. Detector placement is checked by coverage mapping, as described in ISA TR84.00.07. Building fire detection follows NFPA 72 or EN 54 depending on the project and the authority having jurisdiction, while process area F&G functions are normally assigned a SIL under IEC 61511.
IEC 61511 limits the credit you can claim for the basic process control system as a protection layer. The SIS needs its own sensors, logic solver and final elements where the risk assessment says so. We provide read-only links from the SIS to the DCS or SCADA for display and sequence of events, with bypasses and overrides controlled by key switch or permit and logged.
Hardware is the easy part. Most problems we find on site come from inconsistent code, cluttered screens, too many alarms or a poorly defined interface between two vendors.
Ladder diagram, function block diagram, structured text and sequential function charts. Instruction list was deprecated in the 2013 edition. We use typical function blocks for valves, motors and PID loops so every object behaves the same.
A display hierarchy from plant overview to faceplate, grey backgrounds, colour reserved for abnormal states, and trends at the point of decision. Operators spot problems sooner and make fewer mistakes.
An alarm philosophy, rationalisation of every alarm, and priority by consequence and time to respond. The aim is about one alarm per ten minutes per operator in steady operation and no alarm floods after a trip.
| Interface | Where we use it | Points to watch |
|---|---|---|
| OPC UA | Historians, MES, third-party packages, vendor-neutral data models IEC 62541 | Certificate management, security mode set to sign and encrypt |
| Modbus TCP / RTU | Package units, analysers, metering, VFDs TCP 502 | No native security, agree register maps and data types early |
| PROFINET | Remote I/O, drives, MCC intelligent devices IEC 61158 / 61784 | Device names, topology, MRP or system redundancy settings |
| IEC 60870-5-104 | RTU to SCADA and grid operator links TCP 2404 | Information object addresses, time sync, buffered events |
| DNP3 | Utility, water and pipeline RTUs IEEE 1815 | Event classes, secure authentication, unsolicited reporting |
| IEC 61850 | Substation protection relays and power management | GOOSE timing, SCL file exchange between vendors |
Control panels and marshalling cabinets are low-voltage assemblies. For IEC markets we build and verify them to IEC 61439-1 and -2, including design verification of temperature rise and short-circuit withstand, then routine verification on every panel. For North American equipment or client specs that call for it, UL 508A sets the rules for industrial control panels, including the short-circuit current rating. Inside, we separate intrinsically safe and non-IS wiring, segregate 24 V DC from 230 V AC, use interposing relays with push-in terminals for field interfaces, and leave at least 20% spare space and I/O unless the project says otherwise.
Clients and certifying bodies expect each decision to trace back to a standard. These are the ones that shape most control system integration projects.
Safety instrumented systems for the process industry, from hazard analysis through SRS, design, validation and proof testing.
Functional safety of electrical, electronic and programmable systems. The basis for SIL-certified logic solvers and field devices.
Enterprise and control system integration, levels and information models.
Programming languages for programmable controllers.
Human machine interfaces for process automation systems.
Management of alarm systems across the full alarm lifecycle.
High-availability automation networks: MRP, PRP and HSR.
Security for industrial automation and control systems, zones and conduits, security levels.
Low-voltage assemblies, and factory, site and integration acceptance testing.
Each step ends with a document or test the client signs off. That keeps scope clear and stops problems moving downstream to site.
Every project ends with a complete, as-built document set that your maintenance team can use for the life of the plant.
| Document | What it contains |
|---|---|
| Functional design specification | Control narratives, sequences, interlocks, modes of operation |
| System architecture drawing | Controllers, servers, networks, redundancy, ISA-95 zones and conduits |
| I/O list and instrument index | Every signal with tag, range, alarm limits and cabinet address ISA-5.1 |
| Safety requirements specification | Each SIF with SIL, response time, proof test interval and bypass rules IEC 61511 |
| Cause and effect matrices | ESD and F&G initiators against actions, with voting |
| Interface control documents | Register maps, data types, protocols and responsibility split per package |
| Alarm database and HMI style guide | Rationalised alarms with priority and response, display standards ISA-18.2, ISA-101 |
| Panel drawings and test certificates | GA, wiring, heat dissipation, routine verification records IEC 61439 |
| FAT and SAT procedures and reports | Signed test records and punch lists IEC 62381 |
Control equipment that runs well in a European factory can fail early in a Gulf plant. We have more than 17 years of experience across the UAE, Saudi Arabia, Qatar, Oman, Kuwait and Bahrain, and we design for the conditions from day one.
Outdoor ambient can pass 50 °C, with solar gain on top. We size cabinet cooling from real heat loads, derate power supplies and I/O to the vendor curves, and use sunshades or air-conditioned shelters for field panels.
Fine sand and coastal humidity in Dubai, Abu Dhabi, Doha and Dammam attack connectors and fans. We specify suitable IP ratings to IEC 60529, filtered positive-pressure rooms and conformal-coated electronics where the vendor offers them.
Equipment in Zone 1 and Zone 2 is selected to IEC 60079 with IECEx or ATEX certification. We prefer intrinsically safe loops to IEC 60079-11 and check entity parameters for every IS circuit.
Major operators in the region add their own requirements on top of the international standards. Saudi Aramco projects follow SAES documents such as SAES-Z-001 for process control systems and SAES-J-601 for emergency shutdown and isolation systems, with SAMSS material specifications for equipment. ADNOC, QatarEnergy, PDO and KOC each have their own engineering standards and approved vendor lists. We read these at bid stage, raise deviations early and show compliance in the design documents rather than leaving it for site.
System integration rarely stands alone. If you need one contractor to carry the whole scope, see our turnkey control system projects. For older platforms that need replacing or securing, read about control system upgrades and OT cyber security. The networks and power that every system depends on are covered under power distribution and industrial networks, and field device accuracy under industrial instrumentation and calibration. For large site campaigns we can field commissioning teams of 50 or 100 people with their own supervisors.
Short answers to what clients ask us most. For anything specific to your plant, talk to an engineer.
Control system integration is the design, build and testing of a complete automation system from separate products. It joins PLCs, DCS controllers, SCADA, HMIs, safety systems and third-party packages so they share data, alarms and time correctly. The integrator owns the interfaces, so the plant behaves as one system.
A PLC is a controller for fast logic and machine or package control. A DCS is a plant-wide system with one database for controllers, HMI and historian, suited to large continuous processes. SCADA supervises assets spread over a wide area, such as pipelines, with local PLCs or RTUs doing the real-time control.
In most cases, yes. IEC 61511 requires protection layers to be independent, and it limits the risk reduction you can claim from the basic process control system. Safety functions above that limit need their own sensors, a certified logic solver and their own final elements, with only read-only links to the DCS.
It depends on the risk assessment for each function. Process area F&G functions are often assessed under IEC 61511 and may be assigned a SIL, commonly SIL 1 or SIL 2. Building fire alarm systems are usually designed to NFPA 72 or EN 54 instead, as required by the local authority.
Hot standby means two controllers run the same program in step. If the primary fails, the standby takes over without a bump in the outputs. Siemens S7-400H and S7-1500H are examples, and the same idea applies to other vendors' redundant controllers.
Both are defined in IEC 62439-3 and give zero recovery time after a network fault. PRP sends every frame over two fully separate networks. HSR sends frames both ways around a single ring, which saves switches but limits ring size and bandwidth.
IEC 60870-5-104 is the usual choice in Europe, the Middle East and for power utilities. DNP3 is common in water and North American utilities. Both support time-stamped events and buffering when the link is lost, which Modbus does not.
Yes. We work across the UAE, Saudi Arabia, Qatar, Oman, Kuwait and Bahrain from our Dubai and UK offices. We design to the client's own specifications, such as Saudi Aramco SAES documents, alongside the international standards.
Send us your scope and we will come back with a clear technical and commercial proposal. We can price a single PLC panel, a full DCS with ESD and fire and gas, or a SCADA and RTU network. Call +971 54 774 6012, message us on WhatsApp, or use the contact form.
