© 2008 Siemens Energy & Automation, Inc. All Rights Reserved.
PMCM-9340D-0208 ACCESS 9340 and 9360 Meters
2/2008 Chapter 4—Metering Capabilities
EN–53
The meter can accumulate the energy values shown in Table 4–3 in
one of two modes: signed or unsigned (absolute). In signed mode,
the meter considers the direction of power flow, allowing the
magnitude of accumulated energy to increase and decrease. In
unsigned mode, the meter accumulates energy as a positive value,
regardless of the direction of power flow. In other words, the energy
value increases, even during reverse power flow. The default
accumulation mode is unsigned.
You can view accumulated energy from the display. The resolution of
the energy value will automatically change through the range of
000.000 kWh to 000,000 MWh (000.000 kVAh to 000,000 MVARh),
or it can be fixed. See Appendix A—Meter Register List
on page 119 for the contents of the registers.
For conditional accumulated energy readings, you can set the real,
reactive, and apparent energy accumulation to
OFF or ON when a
particular condition occurs. You can do this over the communications
link using a command, or from a digital input change. For example,
you may want to track accumulated energy values during a particular
process that is controlled by a PLC. The meter stores the date and
time of the last reset of conditional energy in nonvolatile memory.
Also, the meter provides an additional energy reading that is only
available over the communications link:
• Four-quadrant reactive accumulated energy readings. The
meter accumulates reactive energy (kVARh) in four quadrants as
shown in Figure 4–7. The registers operate in unsigned
(absolute) mode in which the meter accumulates energy as
positive.
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