- 23 - Rev 2
18.2. Counts as Feedback
A 16-bit value is received from the ITV. The upper 4 bits are 0. The lower 12 bits represent the
count value. The count value indicates the current pressure output of the ITV. The inverse of the
setpoint scaling factor is used to determine the feedback in the unit type selected. The count value
can be converted to pressure units using the following formulas:
βMaximum Pressure Scaling Formulaβ (using ITV Scale Factors):
ππππ
ππππ π·πππππππ = (
ππππππ Γ πππππππ ππππππππ
ππππ
)
βScale Factor Table Formulaβ (using ITV Scale Factors):
ππππ
ππππ π·πππππππ =
ππππππ
πππππ ππππππ
18.3. Using engineering units
Engineering units can be selected from either the webpage or explicit messaging. Below is how to
set the ITV to engineering unit mode using the webpage. Refer to Explicit Messaging to config from
the PLC. Note: Changing to and from engineering mode should be done without a setpoint
command.
1. Select Engineering Unit Mode from the Device Control and Status web page
2. Select the engineering unit desired by selecting the radio button corresponding to the desired
unit type.
3. Check Engineering Unit Check Box
4. Click Submit β Changes will be made immediatelyThe selected engineering unit will be stored in
internal memory and will be retained permanently, even if power is cycled, until a different unit
is selected using procedure 1-3 above.