User's Manual

Rev 1.3 SignalFire Telemetry

Modbus Gateway Register Map

The SignalFire Modbus Gateway by default is assigned Modbus Slave ID number 247. Only the

Gateway status/configuration registers are read at this address. All remote node registers are read

from the slave ID and register address of the remote node, unless slave register remapping used.

Gateway Configuration and Status Messages

Boolean Registers – These are 1-bit coil registers. They can only be written to by Modbus opcode

0x05 (Write Single Coil). To perform the following resets, write a 0xFF00 to the respective coil. Writing

0x0000 to a coil has no effect.

Number

Address

(Offset)

Description

00001

0000

Resets the gateway and radio

00002

0001

Resets the radio leaving the gateway on

00003

0002

Resets all counters to zero (See Read Only Registers 2026-2031)

Read/Write Registers – These are 16-bit read/write registers. They can be written to by Modbus

opcode 0x06 or 0x10 (Write Single and Multiple Registers, respectively) and can be read with Modbus

opcode 0x03 or 0x04 (Read Discrete Input and Holding Registers, respectively). The first three registers

are identical to the previous three write coils and behave similarly. They will be read as 0x0000 and

can be triggered by writing 0xFF00 to them. The remaining must be written with 16-bit values in the

range specified in the table below.

Number

Address

(Offset)

Description

41001

1000

Resets the gateway and radio

41002

1001

Resets the radio leaving the gateway on

41003

1002

Resets all GW status counters to zero (See Read Only Registers 2026-2031)