Rev 1.0
SignalFire Telemetry
26
Modbus Gateway Register Map
The SignalFire Modbus Gateway by default is assigned Modbus Slave ID number 247.
Only
the Gateway status/configuration and remapped 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 Write 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.
Register
Number
Register
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)
Boolean Read Registers
– These are 1-bit coil registers. They can be read by Modbus opcode 0x01 for
discrete outputs, and opcode 0x02 for discrete inputs.
Register
Number
Register
Address
(Offset)
Description
02035
2034
State of Digital Output 1. 0=open, 1=closed (function code 0x01)
02036
2035
State of Digital Output 2. 0=open, 1=closed (function code 0x01)
12037
2036
State of Digital Input 1. 0=open, 1=closed (function code 0x02)
12038
2037
State of Digital Input 2. 0=open, 1=closed (function code 0x02)
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.
Register
Number
Register
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)
