Chapter 4 PAS Application Software
General Meter Setup
80
Series PM172 Powermeters
programmed to generate periodic events at user-defined intervals (see
“Using Periodic Timers”).
Interval timers are not synchronized with the clock. When you run a timer, it
generates a pulsed event that can trigger a setpoint if you have put the timer
into a list of the setpoint triggers. When the setpoint event is asserted, the
timer is restarted, and then generates the next event when the timer interval
expires.
If you want to record interval data at predefined intervals without linking to
other events, just select a timer as a setpoint trigger and specify a data log
file you want to use for recording, in the setpoint actions list. If you want the
periodic data to be recorded in presence of a specific event, select triggers
that will identify your event, and then add the timer at the end of the trigger
list using the AND operator.
Using Time Triggers
If you want the setpoint actions to be synchronized with the clock, for
example, to provide synchronous recording interval data each 15 minutes or
each hour, or to output time pulses through relay contacts, use the time
triggers that generate static events synchronized to the device clock.
You can exercise the default setting for Setpoint #1 in your device as an
example of using time triggers. The setpoint is pre-programmed for data
profiling at 15-minute intervals using data logs #1 and #2.
Using the Voltage Disturbance Trigger
The PM172EH provides the voltage disturbance trigger (found under the
VOLT DISTURB name) that detects all types of the voltage waveshape faults
on any phase caused by fast transient voltages. You can use it for recording
disturbances.
The operate threshold for the voltage disturbance trigger defines the
maximum allowable voltage deviation from the steady-state level above
which the device will declare a waveshape fault. By default, it is specified as
a percent of the nominal device voltage. If you wish to use volts units
instead, you can select the desired voltage disturbance units from the
Preferences tab in the Tools/Options/Preferences dialog.
Ì
The voltage waveforms in 4LN3, 4LL3, 3LN3, 3LL3, 3BLN3 and 3BLL3
wiring modes represent line-to-neutral voltages; otherwise, they will be line-
to-line voltages. Take it into account when specifying the nominal device
voltage that is used as a reference for the disturbance trigger.
The trigger does not respond to slow voltage variations whenever the voltage
rise above or drop below the specified threshold takes longer than 1 cycle
time.
Delaying Setpoint Operations
Two optional delays can be added to each setpoint to extend monitoring
setpoint triggers for a longer time before making a decision on whether the
expected event occurred or not. When a delay is specified, the logical
controller will change the setpoint status only if all conditions are asserted for
a period at least as long as the delay time.
Note that you cannot use delays with pulsed events since they are cleared
immediately and will no longer exist on the next setpoint scan.
Using Setpoint Events and Actions
When a setpoint status changes, i.e., a setpoint event is either asserted or
de-asserted, the following happens in your device:
1. The new setpoint status is logged to the setpoint status
register that can be monitored through communications
from the SCADA system or from a programmable
