4
Signet 5500 Flow Monitor
A. LOW alarm mode
The output is active (relay energized) when the flow drops below the
setpoint, and is inactive (relay de-energized) when the flow rises
above the setpoint plus hysteresis (sec. 9.2 F-G, 9.2 J-K).
• Auxiliary output: ideal for external device
inputs (sec. 4)
• Relay outputs: ideal for external warning
lamps, sirens, etc. (sec. 7)
B. HIGH alarm mode
The output is active (relay energized) when the flow rises above the
setpoint and is inactive (relay de-engergized) when the flow falls
below the setpoint plus hysteresis (sec. 9.2 F-G, 9.2 J-K).
• Auxiliary output: ideal for external device
inputs (sec. 4)
• Relay outputs: ideal for external warning
lamps, sirens, etc. (sec. 7)
Flo
w
Flow
C. PULSE mode
The output is active (relay energized) for the programmed pulse width each time the programmed pulse volume is measured by the flow
sensor (sec 9.2 H-I, 9.2 L-M).
• Auxiliary output: ideal for external device control (sec. 4)
• Relay outputs: ideal for metering pump or solenoid valve control (sec. 7)
FLOW
volume 1
= Programmed pulse
volume (e.g. 12.5 Gal.)
= Programmed pulse
width (relay energize time)
= Output active
(relay
energized)
= Output inactive
(relay
de-energized)
volume
volume 2
volume 3
volume 4
volume 5
volume 6
Flow
Sensor
Low setpoint=
Adjustable hysteresis=
Output active (relay energized)=
Output inactive (relay de-energized)=
High setpoint=
Adjustable hysteresis=
Output active (relay energized)=
Output inactive (relay de-energized)=
Totalizer function
The output emits an adjustable signal pulse width for each whole engineeing unit measured by the flow sensor (also displayed on totalizer).
To enable the totalizer function, the operator must set the relay or auxiliary pulse volume setpoint to 1.0000 (sec. 9.2 H, 9.2 L).
• Totalizer function: ideal for external counter or accumulator use (sec 4.2)
=
adjustable
pulse width
1
2
3
4
VIEW menu
totalizer display
8.3 Totalizer reset (sec. 5):
This feature allows the operator to reset the totalizer with a dry switch contact closure at any time. The
external reset switch overrides software security feature (sec. 5).
8.4 4 to 20 mA output (sec. 6):
The 4 to 20 mA output is internally powered by the instrument. 4 mA and 20 mA setpoints are fully
adjustable within the programmed
fl
ow range (sec. 11 B). The output can also be reverse spanned.
8.5 Relay 1 and 2 outputs (sec 7):
Relay outputs 1 and 2 can be independently con
fi
gured as Low alarm, High alarm, Pulse or Totalizer
output. Refer to diagrams A - C above for operation details.
8. Output
Functions
This section gives a detailed description of all 5500 output functions.
8.1 Sensor pulse output (sec. 3):
This output emits an open-collector frequency equal to the sensor input. The output connects directly
to a second Signet instrument for expanded process control with a single sensor input (sec. 3.1). The output is an open-collector type that
requires an external pull up resistor and power supply for other instrument inputs (sec. 3.2).
8.2 Auxiliary pulse output (sec. 4):
The auxiliary output can be con
fi
gured as Low alarm, High alarm, Pulse or Totalizer output. Output
logic can be selected for either active low (factory default) or active high operation (sec. 9.3 J). The auxiliary output is an open-collector
type that requires an external pull-up resistor and power supply to operate. Refer to diagrams A - C below for operation details.
