Endura APA592
pH / Redox (ORP) transmitter
9 HART Communication
OI/APA592–EN Rev. E
83
9 HART Communication
For ease of identification, each HART device features a configurable 8-character HART tag. In addition to
the HART tag, each device has a HART address (set to the default value 0). At this address, the device
operates in HART standard communication mode (point-to-point operation).
When an address in the range 1 to 15 is used, the device switches to HART multidrop mode. This
operating mode enables users to connect up to 15 devices in parallel to a power supply.
In multidrop mode, an analog output signal that matches the Primary Value is not available. The output
signal in multidrop mode is basically a constant 4 mA and is used exclusively for the power supply. In
multidrop mode, sensor or process data information is available as a HART signal only.
In addition to point-to-point and multidrop modes, the third type of HART communication is burst mode.
When
Burst Mode
is activated, the device transmits a HART telegram continuously, containing process
information approximately every 500 ms without prompting by a HART command – refer to page 69 for
further details of
Burst Mode
.
9.1 HART Device Type Codes
All HART products contain unique identifiers that specify the device type.
The device type code for APA592-PH is 48 (30 hex) under manufacturer type code 26 (1A hex).