11984 Rev 01 Page 3 of 4
4.1 Operation
Modes of operation
The Supervisor has four modes of operation. Two modes: "Pressure Mode" and
"Flow Mode" are used to support the two types of exhaust controllers produced by
Progressive Technologies Inc. In normal operation the SENTRY 1510 uses the
Pressure Mode exclusively.
"Cycle Mode" is used for testing purposes (see section 3, page 10.) "Position Mode"
and "Cycle Mode" are used for factory diagnostics test purposes only.
Pressure Mode
The pressure mode is used in applications where the process variable to be con-
trolled is differential pressure, such as the SENTRY 1510. The differential pressure
can be either positive relative to atmosphere (the reference pressure) or negative
relative to atmosphere. The Supervisor can be programmed to display engineering
units of either millimeters of water column or inches of water column. The SENTRY
1510 has a pressure range from 0 to 25.4 mm (0 to 1 inch) of water column. The
pressure mode is enabled by the menu entry called Operation Mode or "OperMode".
By setting this entry to "Pres" for pressure mode, the Supervisor will operate in
differential pressure mode.
Once the pressure mode has been selected, two other menu entries need to be de-
fined. The first is the Set Point Mode or "StptMode" menu entry. This entry is used
to define the source of the set point as being either a digital set point, via
RS422/RS485 interface or locally via the keypad (Single) or an analog set point via
an analog 0-5 Volt signal (Analog). (The "StptMode" menu selection also contains
options called "Dual" and "Quad". These are used in the "Cycle Mode" as defined in
section3.) In an application where the Supervisor will be used with a 0-5 Volt analog
signal, the set point mode should be set to "Analog". In all other cases, the set point
mode should be set to "Single".
The second menu entry that should be defined is the Control Mode or "CtrlMode"
entry. Two options are available for this entry: closed loop (Cls_Lp) or absolute
position (AbsPos). Closed loop is used to enable the Supervisor PID algorithm for
change in a controller's set point. Closed loop mode should always be used during
operation of the SENTRY 1510. Absolute position is used to enable position mode
(see āSENTRY Supervisor Operation Manualā) and is only used for factory
diagnostics.
The full scale range for the process pressure variable should be defined in the
"Pressure Full Scale" entry. For the SENTRY 1510, the full scale is 25.4 mm water
column. The menu value appears with an implied decimal point, so that full scale
shows as 5080.
Flow Mode
The SENTRY 1510 is not capable of sensing flow, and cannot control the actual
exhaust flow. This mode should not be used with the SENTRY 1510.
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