Bronkhorst®
Instruction Manual MI Series Industrial mini CORI-FLOW™
9.17.120A
28
3.8.1
Digital procedure
FlowPlot provides an easy way to adjust the zero point of an instrument via RS232; the
Auto zero
function automatically
performs the procedure described here
To adjust the zero point using digital communication, set parameter values in the following sequence (see section
for more information about instrument parameters):
Sequence #
Parameter
Value
Action
1
Setpoint
0
stop flow (close control valve)
2
Init Reset
64
unlock secured parameters
3
Control Mode
9
enable calibration mode
4
Calibration Mode
0
reset calibration mode
5
Calibration Mode
9
start zeroing
The green LED starts to blink fast, indicating that the zeroing procedure is being performed. On completion, the green LED
starts to glow continuously, while the output signal is 0% (parameter
Measure
= 0). At the same time, parameter
Control Mode
returns to its initial value. If the procedure is successful, parameter
Calibration Mode
changes to 0 (idle). If the procedure fails,
Calibration Mode
changes to 255.
After performing the procedure, remember to set parameter
Init Reset
to value 0 to lock secured parameters
Alternatively, when HART functionality is enabled, the procedure can easily be performed with a single HART command.
3.8.2
Manual procedure
The internal autozero function of the instrument can be activated with the multifunctional switch, which can be found in
the wiring terminal box (see
).
To start the built-in autozero function with the multifunctional switch, follow these instructions:
1. Change the setpoint of the instrument to 0 (zero)
2. Press and hold the multifunctional switch. After 4 seconds, the red LED
•
starts glowing for 4 seconds, after which the
green LED
•
starts glowing
3. At that moment (which is after 8 to 12 seconds), release the switch
The green LED starts to blink fast, indicating that the autozero function is being performed. On (successful) completion, the
green LED starts to glow continuously, while the output signal is 0% (parameter
Measure
= 0).
