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RI-EA65 / RI-EA60

Protocol converter allowing access to M-Bus devices via Modbus RTU over RS-485.

Operation diagram

sequenceDiagram
    autonumber
    box RS-485
        participant Master
        participant Converter as RI-EA65
    end
    participant Remote as M-Bus Device
    Master->>Converter: Request to M-Bus Device
    activate Master
    activate Converter
    Note over Master,Converter: Modbus RTU over RS-485
    Converter->>Remote: Request to M-Bus Device
    activate Remote
    Note over Converter,Remote: M-Bus
    Remote->>Converter: Response from M-Bus Device
    Note over Converter,Remote: M-Bus
    deactivate Remote
    Converter->>Master: Response from M-Bus Device
    Note over Master,Converter: Modbus RTU over RS-485
    deactivate Converter
    deactivate Master

Configuration and registers

Modbus functions

Supported read functions:

  • Read Holding Registers (FC=03 — 0x03)

Supported write functions:

  • Preset Multiple Registers (FC=16 — 0x10)

Note

Above functions apply to configuration registers only.

Data types

Configuration registers use following data types:

  • u16 - unsigned 16 bit integer
  • u32 - unsigned 32 bit integer

Unlocking configuration registers

Making configuration changes requires unlocking the device.

  • To unlock the device write maintenance or administration password to 0x000C register.
  • Writing incorrect password to 0x000C register will change access level to 0 (guest).

Reading Enter Password register will return current access level:

Setting Default value Unit Register Address Type
Enter Password 0 enum:
0 - guest
2 - maintenance
4 - administrator		 0x000C u16

Note

Device will automatically return to 0 (guest) access level within 24 hours.

Passwords

Passwords can be changed using following registers:

Setting Default value Register Address Type
Set maintenance password 0x0001 0x000D u16
Set admin password Hidden 0x000E u16

Unit number

Mobus unit number ("address") is by default set to 251 (0xFB).

Note

Requests sent to this address will not be forwarded to M-Bus port.

Setting Default value Register Address Type
Unit number
(Address)		 251
(0xFB)		 0x0007 u16

Full Modbus Registers Map

Address Hex Name Type Default Value Description
0x0000 Status 1 u16
0x0001 Status 2 u16
0x0002 Protocol Version u16
0x0003 Serial Number u32 Unique device identifier.
0x0005 Hardware Version u16
0x0006 Firmware Version u16
0x0007 Modbus Unit u16 251 (0xFB) Modbus "address".
0x0008 RS-485 Baudrate u32 9600
0x000A RS-485 Mode u16 1 Default = 8N1
0x000B RS-485 Response Delay u16 100 milliseconds
0x000C Enter Password u16 0
0x000D Set Maintenance Password u16 0x0001
0x000E Set Admin Password u16 Hidden
0x000F Allow Password Reset u16 0
0x0010 Reserved u32
0x001D Reset Period u16
0x001E Reset Device u16
0x001F Reset Device to Factory u16
0x0020 Uptime u32 milliseconds
0x0050 M-Bus Interface Baudrate u16 2400
0x0051 M-Bus Slaves Quantity u16 0 Number of found M-Bus slaves.
0x0052 M-Bus Block/Unblock Search Slave Mechanism u16 0 Enabled by default
0x0053 M-Bus Cache No Update Time u32
0x0055 M-Bus Max Slaves u32 Maximum number of M-Bus slaves.
0x0057 Last Error u16
0x0058 Block Register 1 u16
0x0059 Block Register 2 u32
0x005A Block Register 3 u16
0x005B Block Register 4 u16
0x0060 M-Bus Response Delay u16 Delay before responding on M-Bus.
0x0061 M-Bus Command Delay u16 Delay between M-Bus commands.
0x4000 Debug Mode u16 Enable or disable debug mode.
0x6000 M-Bus Slave Mode u16 Mode of operation for M-Bus slaves.
... M-Bus Slave Mode u16

Mode of operation for M-Bus slaves

M-Bus slave mode registers control how M-Bus reads are performed.

Structure

Value (uint16) has following structure: xxxx xxxx uerr ffff

    x - not used (FFh)

    u - 0 = automatic
        1 = set by user (if set it's "locked" and will not be changed by search mechanism)

    e - bit which indicate slave existing
        1 = slave found
        0 = slave does not exist

    f - function code
        0 = slave does not exist
        1 = REQ_UD2 (default)
        2 = Ram readout
        3 = Debuging Mode
        4 = EEPROM readout
        5 = Mode for preparing yaml files from UD_2 response
        6 = Mode for preparing yaml files from ram readout response
        7 = Mode for preparing yaml files from EEPROM readout response
        254 = Electric Converter Mode (only one value written (it will no saved) into slave and device switching into mode)

    r - reserved for future usage

Example values

  • 0xFF00 - slave does not exist
  • 0xFF41 - slave found by automatic search mechanism, using REQ_UD2 for reading data.

M-Bus Modbus RTU registers map

Request to Modbus addresses pointing to M-Bus slaves use following registers map:

Address Hex Name Type
0x0000 Status 1 u16
0x0001 Status 2 u16
0x0006 Block register u16
0x0007 Block register u32
0x0009 Block register u16
0x000A Block register u16
0x0050 Block register u16
0x0051 Block register u16
0x0052 Block register u16
0x0053 Block register u32
0x0055 Block register u32
0x0057 Block register u16
0x0058 M-Bus Slave Unit u16
0x0059 M-Bus Slave Baudrate u32
0x005A M-Bus Slave Initialization u16
0x005B M-Bus Slave Reset u16
0x0060 M-Bus Response Delay u16
0x0061 M-Bus Command Delay u16
0x4000 Debug Mode u16
0x5000 M-Bus Slave Data Registers Start Address
0xFFFF End of Registers