What This Gateway Does
The G0313 connects Modbus RTU devices to a FOUNDATION Fieldbus (FF) network. It’s a protocol converter that sits between the two systems. On the Modbus side, it communicates over RS485. On the FF side, it connects as a standard FF device.
This is the FF counterpart to the G0306 (Modbus to DP) and G0307 (Modbus to PA). Choose G0313 when your control system speaks FOUNDATION Fieldbus H1.
The gateway acts as a Modbus master. It polls up to 4 Modbus slave devices and converts their data into FF variables that the control system can read through the FF bus.
For detailed configuration examples, refer to the G0313 configuration guide.
Who Uses It
System integrators connecting Modbus devices to FF networks. Plant engineers modernizing older systems where Modbus instruments are still in good condition but the control system is moving to FOUNDATION Fieldbus. Anyone running a mixed protocol environment who wants to bring Modbus data into an FF-based DCS like Emerson DeltaV.
What’s Inside
The gateway has a resource block (RES), a Modbus transducer block (Modbus_TB), and 16 function blocks: 4 analog inputs (AI), 4 analog outputs (AO), 4 discrete inputs (DI), and 4 discrete outputs (DO). It also includes a PID block for basic control applications.
Each AI, AO, DI, and DO supports 8 channels. These correspond to the data that moves between Modbus and FF.
The gateway acts as the Modbus master. It reads data from up to 4 Modbus slave devices and makes that data available to the FF network through function block parameters.
For more details on FF function blocks, see the FF protocol documentation.
Physical Installation
The gateway is DIN rail mountable. Dimensions: 99 x 22.5 x 114.5 mm. Housing is polyamide PA6.6 with polyester epoxy coating.
Terminals:
The gateway has two separate power supplies:
-
FF bus power: 9-32 VDC
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Modbus power: 24 VDC (±20%)
Use shielded twisted-pair cables for both sides. The FF side uses the standard IEC 61158-2 physical layer (31.25 kbit/s).
DIP Switches:
A 3-bit DIP switch is located on the board:
| Switch | Función |
|---|---|
| SIM | Simulation mode enable |
| WP | Write protection – prevents configuration changes |
| RST | Factory reset – restores all settings to default (power off, set to ON, power on, then set back to OFF) |
For wiring diagrams and terminal definitions, refer to the G0313 installation guide.
Configuración
The G0313 is configured through FF configuration tools like:
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NI-FBUS Configurator
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Emerson DeltaV
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Microcyber NCS4000
The Modbus side configuration includes two main areas:
Communication parameters (Modbus transducer block):
| Parámetro | Options |
|---|---|
| Physical medium | RS485 (default) |
| Baud rate | 2400, 4800, 9600 (default), 14400, 19200 |
| Stop bits | 1 (default) or 2 |
| Parity | None, Even (default), Odd |
| CRC order | High byte first (default) or low byte first |
Register mapping (analog and discrete parameters):
The gateway supports 8 analog inputs, 8 analog outputs, 8 discrete inputs, and 8 discrete outputs. Each can be mapped to a specific Modbus register using the following parameters:
| Parámetro | Descripción |
|---|---|
| FROM_EU0 / FROM_EU100 | Input range lower/upper limit (for scaling) |
| TO_EU0 / TO_EU100 | Output range lower/upper limit (for scaling) |
| DATA_TYPE | Register data type (float, unsigned 8/16/32, signed 8/16/32) |
| FUNCTION_CODE | Modbus function code (1, 2, 3, 4, 5, 6, or 16) |
| REGISTER_ADR_OF_VALUE | Modbus register address for the value |
| REGISTER_ADR_OF_STATUS | Status register address (0 = auto-detect) |
Example configuration:
For an analog input reading a holding register:
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FROM_EU100 = 4095
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FROM_EU0 = 0
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TO_EU100 = 100
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TO_EU0 = 0
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DATA_TYPE = “Unsigned16_01”
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FUNCTION_CODE = “FC03 Read Holding Register”
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REGISTER_ADR_OF_VALUE = 14
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REGISTER_ADR_OF_STATUS = 0
This reads register 14 using function code 3, scales the value from 0-4095 to 0-100, and provides it as MOD_IN1. The status is determined automatically by the transducer block.
For step-by-step configuration instructions, visit the G0313 configuration page.
Supported Data Types
The gateway supports a wide range of data types for register mapping:
| Data Type | Descripción |
|---|---|
| Float_0123, Float_1032, Float_3210, Float_2301 | Single precision float with byte order options |
| Unsigned8_0, Unsigned8_1 | 8-bit unsigned integer |
| Unsigned16_01, Unsigned16_10 | 16-bit unsigned integer |
| Unsigned32_0123, Unsigned32_1032, Unsigned32_3210, Unsigned32_2301 | 32-bit unsigned integer |
| Signed8_0, Signed8_1 | 8-bit signed integer |
| Signed16_01, Signed16_10 | 16-bit signed integer |
| Signed32_0123, Signed32_1032, Signed32_3210, Signed32_2301 | 32-bit signed integer |
The suffix (e.g., 0123, 1032) indicates byte order. 0 = low byte first register, 1 = high byte first register, 2 = low byte second register, 3 = high byte second register.
The gateway uses little-endian mode internally.
Monitoreo de estado
BAD_STATUS parameter:
If a Modbus communication fails, the corresponding bit is set to 1. Each of the 32 channels (8 AI, 8 AO, 8 DI, 8 DO) has a dedicated bit.
ERR_LOOK_SEL and ERR_LOOK_RESULT:
For detailed error diagnostics:
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ERR_LOOK_SEL selects which channel to query (0-31)
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ERR_LOOK_RESULT returns the communication response code:
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0x00: OK
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0x01: Illegal function
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0x02: Illegal data address
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0x03: Illegal data value
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0x04: Slave device failure
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0x06: Slave device busy
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0xFF: Communication failure
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If you’re experiencing communication issues, contact Microcyber technical support for assistance.
FF Bus Topology
The G0313 connects to an FF H1 bus segment. Key characteristics:
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Bus length: up to 1900 meters
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With repeaters: up to 10 kilometers
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Termination resistors required at both bus ends
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Standard FF physical layer (31.25 kbit/s)
Default Communication Settings
| Parámetro | Default |
|---|---|
| Modbus slave addresses | 1, 2, 3, 4 |
| Baud rate | 9600 |
| Data bits | 8 |
| Stop bits | 1 |
| Parity | Even |
| CRC order | Low byte first |
Supported Modbus Function Codes
| Código | Operation |
|---|---|
| 1 | Read coils |
| 2 | Read discrete inputs |
| 3 | Read holding registers |
| 4 | Read input registers |
| 5 | Write single coil |
| 6 | Write single register |
| 16 | Write multiple registers |
Especificaciones técnicas
| Parámetro | Valor |
|---|---|
| Modbus power | 24V DC |
| FF bus power | 9-32V DC |
| Insulation | 500V AC between Modbus and FF |
| Temperatura de funcionamiento | De -40 °C a 85 °C |
| Humedad | De 5% a 95% RH |
| Startup time | ≤5 s |
| Refresh time | 0,2 s |
| Protección | IP20 |
| Peso | 0,2 kg |
| Material de vivienda | Polyamide PA6.6, polyester epoxy coating |
Ordering Information
| Producto | Interfaz | Descripción |
|---|---|---|
| G0313 | RS485 | Modbus RTU over RS485 to FOUNDATION Fieldbus |
Browse the full Microcyber gateway product line.
About Microcyber
Microcyber was founded by the Shenyang Institute of Automation, Chinese Academy of Sciences. The company developed the first internationally approved FF H1 protocol stack in China and participated in drafting the EPA standard (now an IEC international standard). Microcyber is a member of FCG, HART, and PNO, and holds ISO 9001:2008 and ISO/TS16949 certifications.
