Primary Analog Output; Engineering Unit; Sensor Range - Setra Systems SRCM Operation

Primary Analog
Output

Engineering Unit

Sensor Range

If selecting Analog Ch1 or Analog
Ch2 for either Primary of Secondary
Room, enter full-scale (FS) range
that matches the transducer being
used
Also enter voltage or milliamp
range that matches the transducer
being used
This Analog Output (AO) is used to communicate the value of the differential
pressure to an external source such as a Building Management System (BMS).
The value is scaled as either 4-20 mA, 0-5 Vdc, or 0-10 Vdc, selectable. A nor-
malized pressure value is generated once every 100 milliseconds. The analog
output is only available for the Primary room.
Units of measurement to show on the Home screen, selectable as either inches
of Water Column ("WC) or Pascals (Pa).
The SRCM is manufactured with an on-board differential pressure transducer.
This transducer is manufactured to specifications for fixed minimum and
maximum pressure measurement, known as the full-scale range of the trans-
ducer. When the on-board transducer is used exclusively, these values cannot
change. Alarm setpoints cannot be set above the positive value or below the
negative value. If a wider or narrower sensor range is required for the project,
an external pressure transducer such as a Setra 264 or Setra 267 may be chosen
to match the requirements. See more above under Primary Room or Secondary
Room.
If an external transducer is used, the full-scale values and other parameters need
to be configured into the SRCM so the unit understands the scale of measure-
Select desired units of mea-
sure to display on the Home
screen, either "WC or Pa.
The unit of measure for the
external transducer must be
selected before entering range
and output of the unit. After
entering all data the units may
be changed and the range will
scale accordingly.
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