MBMap Registry
  1. Devices
  2. Novus
  3. DigiRail-2A

Novus DigiRail-2A Modbus register map

Two-channel universal analog input module (thermocouple, Pt100, mV, V, mA) with Modbus RTU over RS485: channel values, status flags, input configuration, indication limits and tags

  • Official
  • 43 registers
  • Modbus RTU
  • Revision 1 · 2026-10-31
  • Identity: model, firmware, serial number

Official: Written from the manufacturer's documentation, but not tested on a device yet. Check the map against the manufacturer's documentation before you write to a live device. Tested it? Report a test.

Download .mbmap.json Raw JSON View on GitHub Suggest a correction Report a problem

Communication

Protocol
Modbus RTU
Unit ID
247
Serial
1200 8E1 · 1200 baud, 8 data bits, even parity, 1 stop bit
Byte / word order
ABCD · bytes big-endian, words high first
Addresses
0-based

Connection values are defaults: the device may be configured differently.

Map

Registers
43 holding registers
Groups
7
Translation tables
6
Revision
1 · 2026-10-31
Added
()
File
maps/novus/digirail-2a.mbmap.json · 11 KB · history
SHA-256
060cb6c9a6bdffe2cb7e05ccfe86fe415589cc8785c59c6f248e19569e0448ee
Manufacturer
novus.com.br

Device identity

What a tool can read to check that this map fits the connected device (SPEC.md section 4.7). Registers with a role are read like any other register.

Registers
RoleRegisterAddressTypeValues
Serial number Serial number holding 0 uint32 ABCD
Firmware Firmware version holding 5 uint16
Model Model holding 62 uint16 1 = DigiRail-2A, 3 = DigiRail-2R, 4 = DigiRail-4C

Sources and notes

Source: Novus DigiRail-2A communication manual (Portuguese)

  • Factory defaults: address 247, 1200 bit/s, even parity, 1 stop bit. Pressing the RCom button puts the module in diagnostic mode for one minute with address 246, 1200 bit/s, even parity.
  • Functions 03 (read holding registers), 04 (read input registers) and 06 (write single register). The manual lists no write-multiple function, so each setting is written on its own.
  • The channel values are also in input registers 0-1 (percent) and 5-6 (engineering unit); this map reads the same values from the holding registers, which hold the configuration too.
  • Novus recommends configuring the module with its DigiConfig software; the configuration registers are listed so the settings can be checked.
  • The manual does not say how many decimal places the engineering-unit values have: they follow the module's configuration (the indication limits for linear inputs).
  • The manual does not give the character order of the tags; this map assumes the first character is in the high byte.
  • Written from the manufacturer's manual; not tested on a device.
AreaAddressNameTypeAccessUnitScaleDescription
HR 9 uint16 R % ×0.0016129 Linear 0-62000 over the input range, before conversion to the engineering unit (also input register 0)
HR 10 uint16 R % ×0.0016129 Linear 0-62000 over the input range, before conversion to the engineering unit (also input register 1)
HR 14 int16 R In the configured engineering unit, -31000 to 31000 (also input register 5)
HR 15 int16 R In the configured engineering unit, -31000 to 31000 (also input register 6)
HR 7 bool bit 0 R
HR 7 bool bit 1 R
HR 7 bool bit 2 R
HR 7 bool bit 3 R
HR 7 bool bit 4 R
HR 7 bool bit 8 R
HR 7 bool bit 9 R
HR 7 bool bit 10 R
HR 7 bool bit 11 R
HR 7 bool bit 12 R
HR 21 int16 RW
HR 26 uint16 RW Used for thermocouple and Pt100 inputs
HR 31 int16 RW Small correction added to the indication
HR 36 uint16 RW Linear inputs (mV, V, mA) only
HR 41 int16 RW Indication at the bottom of a linear input range
HR 42 int16 RW Indication at the top of a linear input range
HR 51 int16 R Lowest value the channel can show (sensor limit or linear low limit)
HR 52 int16 R Highest value the channel can show (sensor limit or linear high limit)
HR 22 int16 RW
HR 27 uint16 RW Used for thermocouple and Pt100 inputs
HR 32 int16 RW Small correction added to the indication
HR 37 uint16 RW Linear inputs (mV, V, mA) only
HR 43 int16 RW Indication at the bottom of a linear input range
HR 44 int16 RW Indication at the top of a linear input range
HR 53 int16 R Lowest value the channel can show (sensor limit or linear low limit)
HR 54 int16 R Highest value the channel can show (sensor limit or linear high limit)
HR 6 uint16 RW Higher values smooth noisy readings
HR 2 uint16 RW
HR 3 uint16 RW
HR 4 uint16 RW
HR 61 uint16 RW s ×0.1 Used by DigiConfig
HR 0 uint32 ABCD R
HR 5 uint16 R ×0.01 204 is version 2.04
HR 62 uint16 R
HR 126 string[5] RW
HR 131 string[5] RW
HR 136 string[5] RW
HR 141 string[5] RW Unit text for a linear input
HR 146 string[5] RW Unit text for a linear input

Help improve this map

Esc