What is FMCS? Facility monitoring and control in electronics plants: architecture, BMS, PMS and MES

An FMCS (facility monitoring and control system) is the SCADA system that watches and controls the utilities a factory depends on: air handling and cleanroom conditions, chillers, compressed air, water, gases, chemicals and exhaust, with power monitoring alongside it. In semiconductor and electronics plants it is a system of its own, separate from the MES that tracks production, and its scope is wider than a commercial building management system (BMS) because it covers process utilities such as gas and chemical supply as well as the building services. A typical architecture has PLCs, gateways for packaged units, SCADA servers, a historian and operator stations in a central control room.

What the term FMCS means

The clearest public reference is a SEMI standard. SEMI F97, Specification for Facility Package Integration, Monitoring and Control, sets requirements for the architecture, functionality and interfaces of facility monitoring and control systems and for how they communicate with facility package units (FPUs), with chemical, power supply, gas and HVAC units given as examples. SEMI's summary explains why it was written: FPU suppliers often use their own communication concepts, which are not reusable and lead to high maintenance costs. The standard defines a basic set of common services for exchanging status and data, and state models for the units. SEMI lists F97 as Inactive: it no longer meets SEMI's conditions for Current status, but SEMI says Inactive standards remain valid for use.

Vendors use the same expansion. Siemens' 2025 semiconductor blog series has a part on how its "Facility Monitoring and Control System (FMCS)" supports fab sustainability, and a 2026 Rockwell Automation article describes a facility monitoring and control system project with Exyte Group for a multinational technology manufacturer in Penang, with Rockwell as lead automation contractor. Schneider Electric's Korean automation forum expands the same letters differently, as "Factory Monitoring Control System", and defines it as real-time monitoring and control of all equipment that supplies utilities inside a factory: air conditioning, outdoor air units, power and water treatment. The words differ, but the scope described is close.

The reason fabs need such a system lies in the building. A semiconductor cleanroom has to stay within narrow bands of temperature and humidity and is damped against vibration so lithography tools can align at nanometre scale. Below it, a subfab can hold support equipment such as chemical delivery, purification, recycling and destruction systems, and rooftop air handling equipment draws in, cleans and cools outside air. Cleanrooms are classified under ISO 14644-1 by the number of particles allowed per cubic metre; Wikipedia notes that semiconductor facilities often work at ISO class 7 or 5, and gives semiconductor manufacturing as the typical case of a cleanroom kept at positive pressure. All of these conditions are produced by facility systems, and the FMCS is where operators see whether they are being held.

What an FMCS covers

The table lists the utility systems that the sources in this article link to an FMCS or to fab utilities, and what the FMCS typically sees from each.

Many of these arrive as packages from different suppliers, each with its own controller and communication method, which is the problem SEMI F97 describes.

A typical FMCS architecture

The layers are much the same whatever the SCADA platform:

• Utilities and packaged units in the field. Each unit brings its own controller and an interface: BACnet/IP, BACnet MS/TP or Modbus RTU over RS-485, Modbus TCP, or hardwired signals. Field sensors, such as room temperature and humidity sensors, are wired to a PLC, directly or on an RS-485 link.
• Controllers. PLC stations read hardwired signals and run the control that belongs to the FMCS. Wikipedia's article on building automation groups such controllers as PLCs, system or network controllers, and terminal unit controllers for simpler devices.
• Gateways and data acquisition servers. Protocol converters and OPC or driver servers bring packaged units into the SCADA. On the TDL projects described below, BACnet/IP devices come in through BACnet/IP to Modbus TCP gateways and KEPServerEX, and a compressor through a Modbus RTU to Modbus TCP converter.
• SCADA servers and historian. Schneider's FMCS webinar describes a PLC layer that collects data from lower-level equipment and connects to an upper-level SCADA. AVEVA's success story on a global semiconductor company describes a common SCADA platform on AVEVA System Platform, used to manage the consumption of critical utilities such as gas, chemicals, water and power, and to share data across sites. History, trends and automated reports sit on the historian. See what is SCADA and what is a process historian.
• Operator and engineering stations. Operators watch the plant from a central control room; engineers keep PLC programs, SCADA configuration and backups.

Where a site needs redundancy, plan it at the server, controller and network layers; the SEHC maintenance scope below includes redundancy checks and ControlLogix redundancy reconfiguration. The options and their limits are covered in SCADA server redundancy and DLR or PRP.

FMCS, BMS, PMS and MES

BMS. Wikipedia describes a building automation system (also called BMS or BEMS) as the automatic, centralised control of a building's HVAC, electrical, lighting, shading, access control and security systems, sometimes linked to fire alarms and lifts, with the aim of reducing energy use and running costs. Most building devices interoperate through BACnet, an ASHRAE protocol published as ANSI/ASHRAE 135 and ISO 16484-5, or through LonTalk. Siemens describes its Desigo CC platform as a hub for HVAC, lighting, fire safety and security. The FMCS reaches further, into production utilities. On industrial sites the same FMCS can also do the BMS work: TDL's facility monitoring page describes air handling units, outdoor air units and exhaust fans in production and office buildings controlled on PLCs and supervised from the FMCS SCADA.

PMS. A power monitoring system watches the electrical network. Schneider Electric describes its EcoStruxure Power Monitoring Expert as monitoring the electrical distribution, analysing voltage waveforms to find the cause of power quality events, grouping event data into incidents so operators can prioritise alarms, and producing energy and compliance reports. Power quality matters to a fab: SEMI F47, Specification for Semiconductor Processing Equipment Voltage Sag Immunity, sets minimum voltage sag immunity for processing equipment and for subsystems such as chillers, pumps and adjustable speed drives, and a Johnson Controls story on a large semiconductor cleanroom notes that its critical systems had to withstand a two-second power dip. Whether the PMS is a separate product or part of the same SCADA is a site decision; at SEHC the FMCS and PMS are maintained together on AVEVA System Platform.

MES. A manufacturing execution system tracks and documents the transformation of raw materials into finished goods. In the ISA-95 model it sits at level 3, between ERP at level 4 and the control levels below. The MES runs production; the FMCS keeps the utilities that production depends on within limits. Where the MES needs utility data, such as energy or water per product, agree the interface and the tag list explicitly. See what is MES and ISA-95.

Integration challenges

Many suppliers, many interfaces. Chillers, compressors, air handling units, water plants and gas cabinets arrive with their own controllers, and SEMI F97 exists because their suppliers use their own communication concepts. The connect existing equipment page covers the usual routes.

Protocols. BACnet is built for building automation: it defines object types such as Analog Input, Binary Output, Schedule and Trend Log, and runs over IP (BACnet/IP) or over RS-485 as MS/TP. Modbus, first published by Modicon in 1979, runs as Modbus RTU on serial lines, most commonly two-wire RS-485, and as Modbus TCP on port 502; its data model is coils, discrete inputs and 16-bit registers. OPC UA is platform independent, identifies clients and servers with X.509 certificates and can encrypt messages. Older OPC DA links between computers depend on DCOM; see OPC DA and DCOM errors.

Tag naming and point lists. Modbus has no standard way for a device to describe what a register means, so the meaning, scaling and units of every point come from the supplier's register map. BACnet objects are more structured, but each supplier still chooses its own object names. Agree one naming standard and one SCADA template per unit type before the first unit is connected; otherwise each package brings its own names into the historian and the reports.

Alarm floods. Wikipedia's building automation article notes that a momentary power failure can raise hundreds or thousands of alarms from equipment that shut down, and that these should be suppressed and treated as symptoms of the larger failure. A site with hundreds of packaged units needs alarm priorities and suppression rules agreed per unit type. Method: ISA-18.2 alarm management; display design: ISA-101.

Time synchronisation. Events from different units can only be put in order if the clocks agree. AVEVA's Application Server documentation says scripting, alarming and historising need all computers of a galaxy synchronised to the same time; it uses the Windows time service with a time master, preferably the System Management Server node, and warns that a galaxy time master can conflict with time synchronisation already set up in a Windows domain. A node whose clock is outside a set limit, five minutes in AVEVA's example, can make operations such as deployment fail.

Security. The Modbus protocol itself has no protection against unauthorised commands or interception, and a protocol gateway joins two networks. Place the FMCS in its own zones with defined conduits; see IEC 62443.

What to specify

An FMCS specification or RFQ is easier to price and test when it states:

• The list of utility systems and packaged units, with supplier, controller, interface and protocol for each, and the supplier's point list or register map.
• Which points are monitored only and which are controlled from the FMCS, and who owns the control logic: the unit's own controller or an FMCS PLC.
• The tag naming standard, SCADA templates per unit type and display standards.
• The alarm list with priorities, and suppression rules for power dips and planned shutdowns.
• History: which tags, at what resolution, kept for how long, and which reports.
• Redundancy for servers, controllers and networks, and the time source for every node.
• Interfaces to the PMS, the MES and any BMS: which data passes, in which direction.
• Network zones and remote access rules.
• Tests: FAT, then a signal check from each unit to the control room at site.
• Maintenance after handover: backups with restore tests, firmware and redundancy checks.

FMCS work at SEHC

TDL's project pages describe four pieces of FMCS work for Samsung Electronics HCMC CE Complex (SEHC) in Ho Chi Minh City:

• FMCS and PMS maintenance and integration (2025 to now): 17 servers, 14 workstations and 37 PLCs on ControlLogix and AVEVA System Platform with Modbus TCP and EtherNet/IP, under a yearly maintenance contract. PLC stations are checked every six months, with backups, restore tests and redundancy checks; the scope also covers ControlLogix firmware migration, HVAC and utility program changes, and Modbus TCP to EtherNet/IP communication.
• Admin Building AHU and OAC monitoring (2025 to 2026): BACnet/IP to Modbus TCP gateways with KEPServerEX, an AVEVA System Platform application with historian and automated reports, and twelve temperature and humidity sensors on three floors wired on RS-485.
• New air compressor into the FMCS SCADA (2025 to 2026): a new Atlas Copco compressor that could only be monitored locally was connected through a Modbus RTU to Modbus TCP converter and KEPServerEX, with valve, flow meter and sensor signals wired to the PLC, so the central control room sees its data, alarms and history.
• VD5 AHU, OAC and exhaust fan retrofit (2026): one AHU, two OAC units and five kitchen exhaust fans whose Siemens PLCs, HMIs and converters had stopped working were moved to a CompactLogix 5370 controller and brought back into the FMCS SCADA.

The service is described on the facility monitoring (FMCS) page; related services are SCADA and historian and yearly maintenance contracts.