Satec Expertmeter EM720 Operation Manual page 85

Chapter 5 Configuring the EM720
Using Numeric Triggers
Using Binary Triggers
Using Event Flags
EM720 Power Quality and Revenue Meter
when the trigger condition is asserted, and with the AND
operator, if the setpoint should not be operated while the
critical trigger is not asserted.
For numeric (analog) triggers, a setpoint allows you to
specify two thresholds
hysteresis (dead band) for setpoint operations. The
Operate Limit defines the operating threshold, and the
second Release Limit defines the release threshold for the
trigger. The trigger thresholds are always specified in
primary units.
If you use relational operators as "<=" (under or equal) or
">=" (over or equal), always specify a correct Release
Limit for the trigger. If you do not want to use hysteresis,
set the Release Limit to the same as the Operate Limit.
Binary (digital) triggers, as digital inputs, relays, or
internal static and pulsed events, are tested for ON
(closed/set) or OFF (open/cleared) status.
The binary events are divided into two types: static events
and pulsed events. Static events are level-sensitive
events. A static event is asserted all the time while the
corresponding condition
inputs, relays and internal static events generated by the
device diagnostics, metering procedures, and Power
Quality and Fault recorders.
Pulsed events are edge-sensitive events with auto-reset. A
pulsed event is generated for a trigger only once when a
positive transition edge is detected on the trigger input.
The examples of pulsed events are pulse inputs (transition
pulses on the digital inputs), internal pulsed events
(energy pulses and time interval pulses), and events
generated by the interval timers. The logical controller
automatically clears pulsed events at the end of each
scan, so that triggers that used pulsed events are
prevented from being triggered by the same event once
again.
The EM720 has 8 common binary flags, called event flags,
which can be individually set, cleared and tested through
setpoints or remotely.
Event flags can be used in different applications, for
example, to transfer events between setpoints in order to
expand a logical expression or a list of actions that have to
be done for a specific event, or to remotely trigger
setpoint actions from the SCADA system or from a PLC.
See Device Event Flags
flags via PAS.
General Meter Setup
for each trigger
exists. Examples
on how to check and change event
to provide
are digital
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