<7. HART Communication>
7-15
IM 01C25W05-01EN
6. Apply the high limit reference pressure of 30
kPa to the transmitter. We assume that the
output display at this point is 30.15 kPa.
7. Calculate the output error.
Standard pressure value – transmitter output value
Standard pressure value
Output error
×(URV – LRV)
30.00 – 30.15
30.00
×(30.00 – 10.00)= –0.1
=
=
8. The output difference (−0.1 kPa) is added to the
past adjustment value (−0.03 kPa) to calculate
the span adjustment value.
−0.03 + (−0.1) = −0.13 kPa
9. Enter −0.13 for P UTD.
(3) Zero and Span Adjustment for Pressure
Zero and span adjustment can be made for
pressure (Pres 1, Pres 2). Like the previous section,
use the HART configuration tool to make the
adjustment.
• Recalling pressure zero span adjustment
parameters
Recalling
parameters
Pres 1
[Root menu] → Maintenance
→ Pres 1 trim → Pres 1 trim
(method)
Pres 2
[Root menu] → Maintenance
→ Pres 2 trim → Pres 2 trim
(method)
Auto, Lower Pt
Automatic zero adjustment
Auto, Upper Pt
Automatic span adjustment
Manual, Lower Pt
Manual zero adjustment
Manual, Upper Pt
Manual span adjustment
(4) Adjustment Reset
This parameter can be used to reset various
adjustment values to factory default conditions.
The value adjusted with the zero-adjustment screw
can also be reset to the default value using Clear
DP trim.
• Recalling and setting adjustment value clear
parameters
Differential pressure parameter
Recall
parameters
[Root menu] → Maintenance → DP
trim→ Clear DP trim (method)
Pressure parameter
Recalling
parameters
Pres 1
[Root menu] → Maintenance →
Pres 1 trim→ Clear Pres 1 trim
(method)
Pres 2
[Root menu] → Maintenance →
Pres 2 trim→ Clear Pres 2 trim
(method)
7.2.3.10 Analog Output Adjustment
This function adjusts the analog output value. Two
adjustment methods, D/A output adjustment and
scaled D/A output adjustment, are available. The
outputs at 4 mA and 20 mA are adjusted.
(1) D/A output adjustment (D/A trim)
To make adjustments, set D/A trim, connect a
precision ammeter for calibration according to the
displayed message, and set the output values when
4 mA and 20 mA constant current is generated in
parameters.
• Recalling the D/A output adjustment parameter
(D/A trim)
Recall
parameters
[Root menu] → Maintenance → Analog
output trim → D/A trim
(method)
(2) Scaled D/A output adjustment (Scaled D/A
trim)
The output value can be scaled to any value of
your choice, displayed, and set. Messages will be
displayed, so follow them.
Example: Scaling (voltage)
When a 250Ω input resistance is connected
to the current output loop and the voltage
across the terminals is measured with a digital
voltmeter
4 mA DC → 1 V
20 mA DC → 5 V
Connect a calibration instrument that measures
the scaled measurements, measure the output
values when a 4 mA and 20 mA constant
current is generated, and set the readout values
to make the adjustment.
• Scaled D/A output adjustment procedure
Step Analog output parameters
1
Recall
parameters
[Root menu] → Maintenance →
Analog output trim → Scaled D/A
trim (method)
2
Select scaling Select Change.
3
Set the low
side
Set the value to be scaled
(example: 1)
4
Set the high
side
Set the value to be scaled
(example: 5)
5
Adjust the
output
Select Proceed.
6
Execute low
side trim
Set the readout value.
7
Execute high
side trim
Set the readout value.
