Emerson Micro Motion 3711, Руководство по конфигурации и использованию, Страница: 88 / 234

80 Micro Motion
®
Model 3711 Gas Flow Computers
Configuring I/O
2
. Use the Pulse Inputs dropdown list to select Aux PI1 or Aux PI2 .
Note: Do not use PI1 - PIM or PI2 - PIM. These points are not used by the Model 3711.
3
. Enter the tag to be used to describe this input.
4
. Work through the configuration panels in the following order:
• General
• Advanced
• Alarms
7.9.1 Pulse Input – General panel
The Pulse Input – General panel is shown in Figure 7-13. Parameters on this panel are listed and
defined in Table 7-12.
Table 7-12 Pulse Inputs – General parameters
Parameter Description Comments
EU Value If scanning is enabled, displays current pulse input data
according to the setting of EU Options:
• Rate: Displays the Current Rate. See Current Rate for rate
calculation.
• Today’s Total: Displays accumulated quantity, in EUs, for
current contract day.
• Running Total: Displays accumulated quantity, in EUs, since
the last time the rollover value was reached.
If scanning is disabled, the value entered here will override the
pulse input value.
The Conversion/K-Factor has
been applied to all values shown
here.
The Conversion/K-Factor value is
configured in the Pulse Inputs –
Advanced panel. See
Section 7.9.2.
Units Description for the engineering unit (EU) that this PI represents;
10 characters maximum. Examples: PSIG, MCF, Degrees F,
Milliamps, Volts
Scan Period The number of seconds between the beginning of one scan of
the EU Value and the beginning of the next scan. The following
values are updated at the end of each scan period:
• Accumulated Pulses
• Today’s Total
• Yesterday’s Total
• Current Rate
To reduce the load on the
processor, set Scan Period to a
longer value.
To avoid extreme fluctuations in
rate, set Scan Period so that there
are at least ten pulses per scan
period at conditions of low flow.
Accumulated
Pulses Displays the number of pulses currently recorded in the internal
pulse counter. The internal pulse counter is updated at the
beginning of each scan period. Maximum value = 16,000,000. At
that point, the internal pulse
counter rolls over to zero.
Today’s Total Quantity, in EUs, accumulated since the most recent contract
hour. Today’s Total is automatically reset to 0 at each Contract
Hour. The Conversion/K-Factor has
been applied to the value shown
here.
See Section 3.4 for information on
configuring the contract hour.
Yesterday’s Total The previous day’s Today’s Total at the Contract Hour, just
before it was reset.
Current Rate Rate calculated from the data from the most recent scan. The
rate is expressed in EUs per Rate Period. The following formula
is used: Rate Period is configured in the
Pulse Inputs – Advanced panel.
See Section 7.9.2.
Rate
Pulses/ScanPeriod
RatePeriod
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Conversion/K-FactorValue
×
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