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FW-F018-P-M_v0404_01_EN.docx
3.3.8
EXPLANATION OF SETUP-MENU 7 - ANALOG
A linear analog 4 - 20mA signal is generated according to the linearized flow rate. The settings for
flow rate (SETUP - 2) influence the analog output directly.
The relationship between rate and analog output is set with the following functions.
PV LRV and PV URV define de range of the analog output. Suppose the flow rate is 1000 l/s
If URV is set at 1600 l/s and LRV is set at 0 l/s, then the output current will be:
1000/1600 * (20mA-4mA) + 4mA = 14mA.
Before changing these settings, be sure that the analog signal is not being used for
any application!
SETUP
FUNCTIONS
AND
VARIABLES
7
ANALOG
7.1
PV-LRV
Primary variable Lower Range Value
This setting sets the flow rate value at which the analog output should
generate 4mA.
The decimals, unit and time unit are according SETUP 2.1 and 2.2.
The analog output value can be programmed “up-side-down” if
desired by switching the PV LRV and PV URV value. Please enter the
high flow rate value here
7.2
PV-URV
Primary variable Upper Range Value
This setting sets the flow rate value at which the analog output should
generate 20mA.
The decimals, unit and time unit are according SETUP 2.1 and 2.2.
The analog output value can be programmed “up-side-down” if
desired by switching the PV LRV and PV URV value. Please enter the
low flow rate value here.
7.3
LOOP CURRENT
MODE
Loop current mode sets the output current fixed to 4mA
(for multidrop purposes) or in normal mode.
7.4
LOOP TEST
The loop test is meant to be able to calibrate the 4 and 20 mA values
with SETUP 7.5 and 7.6.
The loop current mode has to be set to
‘enabled’ for this loop test to
function! After a reset or power loss, this setting is reset to off, which
means normal operation.
7.5
TUNE LO
The initial minimum analog output value is 4mA. However, this value
might differ slightly due to external influences such as temperature for
example. The 4mA value can be tuned precisely with this setting.
After pressing PROG, the current will be about 4mA. The current can
be increased / decreased with the arrow-keys.
The new value will become active after pressing ENTER.
7.6
TUNE HI
The initial maximum analog output value is 20mA. However, this
value might differ slightly due to external influences such as
temperature for example. The 20mA value can be tuned precisely
with this setting.
After pressing PROG, the current will be about 20mA. The current can
be increased / decreased with the arrow-keys. The new value will
become active after pressing ENTER.
