Liquid Dosing Control Manual
9.17.150 rev A – September 2020
Page
22
of
34
3.4 Zero procedure
Preconditions
- The system is filled with fluid
- The Liquid Flow Controller has been powered on for > 30 minutes
- The ambient conditions match the operating environment of the instrument
1. Ensure zero flow through the instrument
(
note
, a pump system does not have a shut-off function and undesired flow can occur due to
upstream or downstream pressure variations)
- Write value 0 to parameter 9 – Setpoint
(setpoint 0)
- Close shut-off valves upstream and downstream of the instrument
2. Execute zeroing procedure
- Write value 64 to parameter 7 – Init Reset
(unlock secured parameters)
- Write value 9 to parameter 12 – Control Mode
(enable calibration mode)
- Write value 0 to parameter 58 – Calibration Mode
(reset calibration mode)
- Write value 9 to parameter 58 – Calibration Mode
(start zeroing)
3. Complete zeroing procedure
- Wait until the Green LED changes from fast blinking to solid (approx. 30 seconds)
- Parameter 12 – Control Mode returns automatically to its initial value
- Parameter 58 – Calibration Mode changes to 0 (idle) when procedure is succesfull
-
Parameter 58 – Calibration Mode changes to 255 when the procedure has failed
-> troubleshooting procedure
4. Finalize zeroing procedure
- Write value 82 to parameter 7 – Init Reset
(lock secured parameters)
-
Open shut-off valves upstream and downstream of the instrument to resume operation
Step DDE ProPar Name
Data
Type Execute Value
Remark
Unlock Secured Parameters
1
7
0/10
Init Reset
Uint8
write
64
Unlock secured parameters
Factor
2
12
1/4
Control Mode
Uint8
Write 9
Calibration Mode
3
58
115/1
Calibration Mode
Uint8
Write 0
Reset Calibration Mode
4
58
115/1
Calibration Mode
Uint8
Write 9
Auto Zero Mode
5
58
115/1
Calibration Mode
Uint8
Read 0 - 255 0 = Auto Zero Ok
255 = Auto Zero Error
Lock Secured Parameters
6
7
0/10
Init Reset
Uint8
write
82
Lock secured parameters