Rogue Engineering 1950-250 - Manual (Page 12)

Modbus/SDI-12 Gateway User Manual Page 12 of 12
Last Updated: August 20, 2013
SDI-12 Utility Commands
These are for internal use by the SDI-12 Configurator software, and are basically pass-
through that allow the software access to some SDI-12 utility type commands. All of these
commands cause a command to be sent to an SDI-12 sensor immediately, and then wait for a
response. There is a potential for delay/failure if the SDI-12 translator is currently waiting on a
measurement, so these are mainly intended to be used for initial setup before completely
configuring a sensor's commands.
SDI-12 Command Description Protocol
Query Address When only one unit is on
the SDI-12 bus, this can
find its address. Send to any Modbus address, FCN3, register
16000, 1 register; on success, returned value is
ASCII value of address, i.e., 65 for 'A'
Set Address When only one unit is on
the SDI-12 bus, this can
modify its address. Send to any Modbus address, FCN6, register
16000, value is ASCII value of new address;
success indicates address was set
Get Identification Returns 32 bytes of
configuration information
for an SDI-12 sensor.
Send to Modbus address of SDI-12 address,
i.e., Modbus address 48 for SDI-12 address '0'.
FCN3, register 16001, 32 registers; returns 32
byte identification in 32 registers
Ack Active Checks to see if an SDI-
12 address is active. Send to Modbus address of SDI-12 address,
i.e., Modbus address 48 for SDI-12 address '0'.
FCN3, register 16033, 1 register; returns 1 on
success
Table A4 – Sensor Utilities Commands List