User Manual

10/15/2012 Page 8 of 12

SignalFire Telemetry

Section 3: Remote Modbus Register Mapping

The Sentinel Node sends data to a SignalFire Telemetry Modbus gateway. The data that

is sent to the gateway is available at the gateway in registers where it can then be read by

a Modbus RTU. Consequently, the node needs to have a unique (to the network it is in)

Modbus slave ID which the gateway will use to store its unique data. The ID is set via

the DIP switch on the board.

Modbus Registers

Every check-in period, the sensors are read and data is sent to the gateway. The gateway

will save the data under the set Modbus ID in 16-bit registers. The register map for this

system is:

Number

Address

(Offset)

Description

44001 4000 HART ID 1: Manufacturer’s ID Code/Device Type (ID=MSB, Device=LSB)

44002 4001 HART ID 1: Device ID Number (ID high bite = MSB, ID mid byte = LSB)

44003 4002 HART ID 1: Device ID Number, HART Status (ID low byte = MSB, Status = LSB)

44004 4003 HART ID 1: PV & SV Units Code (PV=MSB, SV=LSB)

44005 4004 HART ID 1: TV & QV Units Code (TV=MSB, QV=LSB)

44006-44007 4005-4006 HART ID 1: Primary Variable (PV) (two registers) (float)

44008-44009 4007-4008 HART ID 1: Secondary Variable (SV) (two registers) (float)

44010-44011 4009-4010 HART ID 1: Tertiary Variable (TV) (two registers) (float)

44012-44013 4011-4012 HART ID 1: Quaternary Variable (QV) (two registers) (float)

49988 9987 or 65524 Major revision number for the mainboard

49989 9988 or 65525 Minor revision number for the mainboard

49990 9989 or 65526 Major revision number for the radio

49991 9990 or 65527 Minor revision number for the radio

49992 9991 or 65528 High 16 bits of SFTS node address

49993 9992 or 65529 Low 16 bits of SFTS node address (the radio ID)

49994 9993 or 65530 Slave ID readback

49995 9994 or 65531 Received signal strength of last packet from the slave

49996 9995 or 65532 Battery voltage of the Modbus client, in millivolts

49997 9996 or 65533 Minutes until this slave will time out, unless new data is received

49998 9997 or 65534 Number of registers cached for this slave device

49999 9998 or 65535 Remote device type. 43 for Sentinel HART

The status registers are only available from the 49988-49999 (9987-9998) address range

if the Gateway is running firmware 7.52 or higher.