Relay Operation Details; Overview; Relays Auto Initialization; Fail-Safe Operation - FlowLine DataView LI55 Instruction Manual

DataView™ LI55 Level Controller

RELAY OPERATION DETAILS

Overview

The relay capabilities of the meter expand its usefulness beyond simple
indication to provide users with alarm and control functions. These capabilities
include front panel alarm status LEDs as well as either 2 or 4 optional internal
relays and/or 4 external relays expansion module. Typical applications include
high or low temperature, level, pressure or flow alarms, control applications such
as simple on/off pump control, and pump alternation control for up to 8 pumps.
There are four basic ways the relays can be used:
1. High or Low Alarms with Latching or Non-Latching Relays
2. Simple On/Off Control with 100% Adjustable Deadband
3. Sampling (Based on Time)
4. Pump Alternation Control for up to 8 Pumps

Relays Auto Initialization

When power is applied to the meter, the front panel LEDs and alarm relays will
reflect the state of the input to the meter. The following table indicates how the
alarm LEDs and relays will react on power-up based on the set and reset points:
Alarm HI or LO
# Alarm
1 HI
2 LO
3 LO
4 HI

Fail-Safe Operation

The following table indicates how the relays behave based on the fail-safe
selection for each relay:
Fail-Safe Non-Alarm State
Selection
NO
Off Open
On Closed
Note: NO = Normally Open, NC = Normally Closed. This refers to the condition of
the relay contacts when the power to the meter is off.
MN301033 Rev B1
Set Point Reset Point
1000 500
700 900
250 400
450 200
Alarm State
NC NO
Closed Closed
Open Open
Instruction Manual
Power-Up
Reading
499
499
499
499
Power Failure
NC
Open Relays go to non-
alarm state
Closed Relays go to alarm
state
Relay &
LED
Off
On
Off
On
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