Model 2000 Flow Computer Instruction Manual
3.0 INSTALLATION, INITIALISATION & CALIBRATION
Model 2000 issue 21 Page No
62
Once the password has been entered and accepted a calibration sub menu will appear as follows:-
Outputs
Selects calibration of any Analogue output.
Analogue
Selects calibration of any Analogue input.
Hart
Selects calibration of any Hart Loop input.
Exit
Returns operation to the Main Menu.
Each Hart input calibration page relates to a specific Hart Loop the position of the loop will be shown on the top left hand
corner of the calibration page and will refer to SLOT 1 to 5 defining the User board positions (See figure 2 for positions) and
Loop 1 or 2 (See External Connections for connections). The Hart Calibration page will show all transmitters (up to 3)
currently configured for that loop and the process variables and units being read from them. The Calibration page will allow
the communication to the Hart transmitters to be switched ON (Normal condition) or to be switched OFF (Calibrate condition)
So that a Hart loop calibrator can be connected to the system and each of the connected transmitters calibrated or checked.
NOTE it is not possible to individually turn off the transmitters on one loop , all must be either ON or OFF. The user can go
on to calibrate as many Hart or Analogue input parameters as are required. Once all the changes are complete the user can
Exit the EDIT section by selecting the function key EXIT. Selecting the EXIT function will prompt with a EXIT menu as
follows:-
Exit & Save
Exit the calibration mode, save the changes to memory and use the new values.
Exit & No Save
Exit the calibration mode, do not action any of the changes made.
Undo
Do not exit calibration mode and undo all previous changes in this session.
Any HART loop left in the OFF state when exiting the Calibrate mode will automatically be switched ON when the unit is
returned to the running condition.
3.5.1.3. ANALOGUE INPUT SIGNALS
The Analogue input signals to the Model 2000, normally used for pressure, temperature, selected gas data or dp will require
calibration as follows:-
The active input signals to the Model 2000 are calibrated by using the keyboard to enter the calibration data. The
Model 2000 display shows the parameters to be entered and the scroll keys can be used to step through the
calibration parameters from start to finish to ensure all of the calibration data is entered.
NOTE: If a routine calibration check is being carried out, the scroll keys can be used to select the parameter which is
required for checking passing through other parameters.
Calibration of the temperature inputs when platinum resistance thermometers are used must be carried out with any zener
barriers in the circuit to avoid errors due to differing barrier resistance.
When the CALIBRATION menu item is selected the user will be prompted to enter a four digit numeric password, to gain
access to the calibration pages. It is possible to set-up a maximum of three different passwords and each of these passwords
can be set to allow access or not to the calibration pages. In its factory default condition the three available passwords are
1111, 2222 and 3333. Once the password has been entered and accepted a calibration sub menu will appear as follows:-
Outputs
Selects calibration of any Analogue output.
Analogue
Selects calibration of any Analogue input.
Hart
Selects calibration of any Hart Loop input.
Exit
Returns operation to the Main Menu.
Each Analogue input calibration page relates to a single input parameter and will show the item being calibrated and its
circuit board position, a High and Low calibration point and the current value for that input. The display cursor can be moved
between the High and Low Calibration values using the [ ↑ ] (for up) and [ ↓ ] (for down) cursor keys and selecting by
pressing the enter or return key. The new value is then entered using the numeric key pad and finally pressing the enter or
return key to confirm.
At this stage in the calibration session the High and Low calibration point number changes have been recorded but are not
being used by the Model 2000. The input parameter should now be physically altered until it corresponds to the High or Low
calibration point and the display cursor set to point at which ever (High or Low) calibration point is being entered. The SET
function key should be operated to set the physical input variable to the High or Low calibration point. The procedure can
then be repeated for the other calibration point and can also be repeated as many times as required. It is recommended that
the High and Low calibration points are as far apart in the span of the input as is practical and that should at least be at the
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