SMART Pressure Transmitter
FT3351 Series User Manual
July.2022
21 |
P a g e
FAHM Co
.
Industrial Automation
Doc. FT3351Rev1401-05
parameter
display
Parameter tuning structure
Hart Protocol
Poll ID
(configuring
identification
number of device in
hart multi-drop bus)
Press <M> until this page is appeared on LCD. Then press
<Z> to access the Poll ID parameter (programing mode).
You can select the device identifier by pressing <S>. After
that, press <Z> until all characters blink. Then press <M>
for the saving new parameter and switching from
programing mode to operation mode.
According to Hart protocol, user can select a number between 0 and 15 as poll identifier. If user
select zero, the device multi-drop mode will be disabled and the current output will show the
primary variable value. But if user select a number greater than zero, the device will go into
multi-drop mode and the output current will be fixed at 4.0 mA.
3.2.6
Tank application parameters
The device can be used in tank application parameters. In this application device will mount at
the bottom of a tank and the pressure measured value of device will be related to level, volume,
math or density of liquid in the tank. The main formulas for calculating the user’s desired variable
are as bellow:
𝑃 = ρ. g. (h − h₀)
v = A. h
𝑚 = ρ. v
ρ is density of liquid, g is the gravity of earth, h is the current height of liquid in the tank, h₀ is the
position of transmitter relative to tank floor, v is the current volume of liquid in tank, m is the
current mass of liquid in the tank and A is the tank surface area. Due to selected mode of device
in “Device-Mode” menu item, the device needs some parameter to calculate the user’s desired
variable.
If Level mode is selected user must determine the level unit, the density unit, transmitter position
(h₀), the liquid density (
ρ)
, low level value equivalent to 4.0mA output (LRV) and high level value
equivalent to 20.0mA output (HRV).
If Volume mode is selected user must determine the level unit, volume unit, density unit,
transmitter position (h₀), density of the liquid (
ρ)
, the tank total height (H), the tank total volume
(V), low volume value equivalent to 4.0mA output (LRV) and high volume value equivalent to
20.0mA output (HRV).
If Mass mode is selected user must determine the level unit, volume unit, mass unit, density unit,
transmitter position (h₀), density of the liquid (
ρ)
, the tank total height (H), the tank total volume
(V), low mass value equivalent to 4.0mA output (LRV) and high mass value equivalent to 20.0mA
output (HRV).
