SFC3000 Optional Boards: Stream and Communication Cards

What Are the SFC3000 Optional Boards?

The SFC3000 optional boards are the plug-in cards that equip the chassis of the flow computer according to the application. These cards fall into two main groups: stream input/output boards, which read the field signals of a metering stream and issue the control outputs, and communication boards, which connect the device to host systems, to a printer and to other metering equipment.

Each board has its own 32-bit processor and runs the measurement, communication and input/output functions on the card itself. Thanks to this distributed structure, the load on the central processor does not grow in step with the stream count. The chassis holds up to six user plug-in cards, and because fiscal measurement uses one stream board per stream, the card split has to be planned at the start of the project.

Board selection should follow not only today's signal list but also the valve, alarm and communication needs that will be added later. Proving applications, for example, call for a large number of valve signals, and in that case the switch stream board with its higher digital input and output capacity is the better choice.

The Role of the Boards in the System

The SFC3000 optional boards form the interface between the field and the calculation:

1. Reading the signals: Pulse and frequency inputs read the meter signals, HART (Highway Addressable Remote Transducer) loops and analogue inputs read pressure, temperature and differential pressure values, and the PRT (platinum resistance thermometer) input reads a resistance thermometer.

2. Serial device communication: The serial port on the stream board sets up Modbus master/slave communication with ultrasonic and Coriolis meters, gas chromatographs, water cut meters and turbine meter encoders.

3. Control and telemetry outputs: Digital outputs serve alarm indication, telemetry and valve control, while analogue outputs are used for telemetry or PID (proportional-integral-derivative) control.

4. Host system connection: Communication boards connect through serial and Ethernet ports to SCADA, DCS and RTU systems, to a network printer and to other flow computers.

Stream input/output boards

There are four stream board options. The digital stream board (3000-314) is the basic card for pulse-oriented streams; the digital two-stream board (3000-319) offers more digital and analogue outputs; the analogue stream board (3000-316) is intended for streams that need 4–20 mA inputs; and the switch stream board (3000-317) provides selectable configurable channels for applications with heavy valve and status signalling. All four boards carry three pulse/frequency inputs; the differences appear in the number of HART loops, analogue inputs and outputs.

Communication boards

The communication board (3000-305) carries three serial ports and one Ethernet port. The serial ports can be configured as RS232 or RS485, include an RS485 termination network and galvanic isolation, use RJ45 style connectors and run at speeds up to 38400 baud. One of the ports can serve a serial printer with handshaking. The Ethernet port provides a 10/100 LAN connection, Modbus master and slave communication over TCP/IP, remote operation and diagnostics, web server functions, network time protocol, networking to other SFC3000 machines and other measurement devices, and network printing. The dual network board (3000-318) adds a second Ethernet port to the same feature set.

Card slot planning

The six slots in the chassis are shared between stream and communication boards. On a five-stream fiscal station, five stream boards leave only a single slot, so the whole communication requirement has to be met by one card. If more serial ports or a second Ethernet port are needed, the balance between stream count and communication boards has to be reconsidered, or a second device planned.

Board codes should be verified when ordering: the codes on the manufacturer's current product page may differ from those used in earlier product literature.

Key Features of the SFC3000 Optional Boards

·         Three pulse/frequency inputs: Every stream board carries three pulse counting and frequency measurement inputs from DC to 5 kHz, suitable for turbine, rotary and positive displacement meters as well as density and relative density meters.

·         HART loops: Two HART transmitter loops on the digital boards, with up to three transmitters on each loop. Pressure, temperature, differential pressure or multivariable transmitters can be connected.

·         Direct PRT input: A four-wire direct PRT input on the digital and analogue stream boards for connecting a resistance thermometer.

·         Analogue input option: The analogue stream board offers three 4–20 mA inputs plus one selectable 4–20 mA input or digital output.

·         Digital outputs: Optically isolated open collector outputs, 30 V max and 10 mA, used for alarm indication, telemetry and valve control.

·         Analogue outputs: 0–20 mA or 4–20 mA, 16-bit resolution with a maximum error of 0.15%, for telemetry or PID control.

·         Prover output frequency: On the stream boards, digital output 1 can be used for the prover output frequency.

·         Serial device integration: A Modbus link through the serial port on the board to ultrasonic and Coriolis meters, gas chromatographs, water cut meters and turbine meter encoders.

·         Selectable channels: Six channels on the switch stream board can be configured as digital status inputs or digital outputs.

·         Isolated serial ports: Galvanic isolation, an RS485 termination network and RJ45 style connectors on the communication board.

Board Comparison Table

The input and output capacity of the SFC3000 optional boards is compared below; all stream boards carry three pulse/frequency inputs.

Key Advantages

·         Scales with the application: When the signal inventory changes, the board changes rather than the device, so the investment is protected.

·         Distributed processing power: Because each board has its own processor, calculation performance holds up as the stream count rises.

·         Mixed signal support: Pulse, HART, analogue and serial signals are handled within the same board family, which reduces the need for intermediate converters.

·         Prover compatibility: High digital input and output capacity together with the prover output frequency supports verification runs.

·         Flexible communication: Serial and Ethernet options, and the dual-port board, suit redundant or segregated network topologies.

·         Easy field replacement: The plug-in board structure allows rapid replacement from a spare board stock, which keeps downtime short.

Application Scenarios

Selection among the SFC3000 optional boards varies with the signal structure of the stream.

Gas stream with pulse meters

A digital stream board on gas streams with turbine or rotary meters; pressure and temperature transmitters are read over the HART loops and the digital outputs serve alarm and telemetry duties.

Liquid stream dominated by analogue signals

An analogue stream board on liquid streams where 4–20 mA transmitters predominate; the selectable input/output channel covers the remaining signals.

Prover and valve-intensive applications

A switch stream board where the verification run needs a large number of valve and status signals; its six selectable channels can be used as inputs or outputs.

Communication with several systems

A communication board on stations where SCADA, DCS and a local printer coexist; where separate network segments are required, a dual network board is preferred.

Board Selection Criteria

The combination of SFC3000 optional boards is settled by assessing the signal inventory and the communication topology together.

Signal inventory

·         Number of pulse/frequency inputs per stream

·         Number of HART loops and transmitters

·         Need for a direct PRT input

·         Number of 4–20 mA inputs

·         Number of digital outputs for alarm, telemetry and valve duties

·         Number of analogue outputs for PID or telemetry

Communication topology

·         Number of host systems and their protocols

·         Serial line length and the RS485 termination requirement

·         Whether one or two Ethernet ports are needed

·         Printer use and reporting over the network

·         Serial device integration: ultrasonic meter, gas chromatograph, water cut meter

Redundancy and expansion

·         Leaving a card slot free

·         Spare board stock

·         Number of streams to be added later

·         Need for a segregated network or a second communication path

Boards should not be selected before the signal list is drawn up; one missing digital output or HART loop means an extra board and rewiring at the commissioning stage.

Signal Standards and Compliance

The signal processing and communication features of the SFC3000 optional boards rest on the following references:

·         ISO 6551 / API Chapter 5.5: The signal standards applied on the pulse counting and frequency measurement inputs.

·         HART: Digital communication on the transmitter loops; up to three transmitters per loop.

·         Modbus: ASCII or RTU on serial lines, and master and slave communication over TCP/IP on Ethernet.

·         Network time protocol: Clock synchronisation over the Ethernet port, which matters for consistent time stamps in custody transfer.

·         Galvanic isolation: Isolation and an RS485 termination network on the serial ports of the communication board.

TLY Enerji Configuration Support

Choosing boards is less about picking items from a list than about drawing up the signal inventory correctly. Starting from the project data, TLY Enerji prepares the per-stream input/output list, settles the combination of SFC3000 optional boards and plans the remaining card slots for streams to be added later.

On the communication side, the station topology, the host system protocols and the cabling distances are assessed to determine how many serial and Ethernet boards are required. The in-panel terminal plan, the breakout module and the cable selection are handled together, and signal tests and communication verification are carried out during commissioning.

For the operating period we provide a spare board plan, configuration backups and technical support for rapid replacement in the event of a fault.

·         Preparation of the signal inventory and the input/output list

·         Board combination and slot planning

·         Communication architecture and cabling proposal

·         Signal and communication tests at commissioning

·         Spare board and maintenance plan

Frequently Asked Questions

Which stream board options are available?

There are four stream boards: the digital stream board (3000-314), the digital two-stream board (3000-319), the analogue stream board (3000-316) and the switch stream board (3000-317). All four carry three pulse/frequency inputs; the differences lie in the number of HART loops, analogue inputs and digital or analogue outputs.

What is the difference between the digital and the analogue board?

The digital stream board offers two HART loops and five digital outputs, but no separate input for analogue measurement signals. The analogue stream board has one HART loop alongside three 4–20 mA inputs and one selectable 4–20 mA input or digital output. On streams where analogue transmitters predominate, the analogue board is the better fit.

Which board suits prover applications?

A prover run needs a large number of valve and status signals. The switch stream board offers three status inputs, six digital outputs and six selectable channels that can be configured as inputs or outputs, so it adds capacity for these applications. On the stream boards, digital output 1 can carry the prover output frequency.

How many HART transmitters can be connected?

The digital stream boards have two HART loops and up to three transmitters can be read on each loop. Pressure, temperature and differential pressure transmitters can be connected individually, or multivariable transmitter types can be used. The analogue stream board has one HART loop.

What does the Ethernet connection provide?

The 10/100 Ethernet port on the communication board provides Modbus master and slave communication over TCP/IP, remote operation and diagnostics, web server functions, clock synchronisation through network time protocol, networking to other devices and printing over the network. Where two separate networks are needed, the dual network board is used.

Why do the board codes sometimes differ?

The board codes on the manufacturer's current product page may differ from those used in earlier product literature. We recommend confirming the board code and its capacity against current manufacturer documentation before ordering; TLY Enerji carries out that confirmation at the quotation stage.