Azbil JTD720A, User Manual, Page: 15 / 76

Azbil Corporation Functions, Configurations, and Structures of model JTD720A and communicator
Model JTD720A - Smart Multivariable Transmitter 1-5
1-3 : General information and procedures for
configuration
The model JTD720 Differential Pressure Transmitter has six operation modes:
MEASURE mode, DP mode, PP mode, PT mode, INPUT mode, and OUTPUT
mode, as shown in Table 1-1. The DP, PP, PT modes are collectively referred to as
CALIBRATION mode:
Table 1-1 Operation modes of transmitter
Mode Description
MEASURE
mode
The transmitter delivers an output signal which has been
corrected for static pressure and temperature. Normally, the
transmitter is run in this mode.
CALIBRATION mode
DP mode The transmitter delivers an output current signal corresponding to
the differential pressure input signal (4 mA (0%) for DP-LRV and
20 mA (100%) for DP-URV). This mode is used also for setting
and calibration of the differential pressure sensor (setting and
calibration of DP-LRV nad DP-URV).*1
PP mode The transmitter delivers and output current signal corresponding
to the static pressure input signal (4 mA (0%) for PP-LRV and 20
mA (100%) for PP-URV). This mode is used also for setting and
calibration of the static pressure sensor (setting and calibration of
PP-LRV and PP-URV).*1
PT mode The transmitter delivers and output current siganal corresponding
to the temperature input signal (4 mA (0%) for PT-LRV and 20
mA (100%) for PT-URV). This mode is used also for setting and
calibration of the temperature sensor (setting and calibration of
PT-LRV nad PT-URV).*1
INPUT mode The transmitter accepts simulated differential pressure, static
pressure and temperature signals, and delivers an output signal
that has been corrected for static pressure and temperature.
OUTPUT mode The transmitter acts as a constant-current signal source. This
mode is also used for calibration of the D/A converter
~Note *1: For calibration, use a sufficiently accurate input signal. If you
attempt zero calivration with a value more than 3% of URV (the
maximum value for the measuring range of the sensor) or span
calibration with a value more than 3% of the span that existed before
calibration, the transmitter may exhibit symptoms similar to those
exhibited by a transmitter experiencing a non-critical error.