Schweitzer Engineering Laboratories SEL-734 - Analog Output

8.17
Date Code 20090730 Instruction Manual SEL-734 Meter
Logic
Analog Output
Analog Output
The optional analog output/digital output (AO/DO) card for the SEL-734
provides four analog outputs (AO401–AO404) and four solid-state digital
outputs (OUT401–OUT404). Each analog output acts as a programmable
transducer. The SEL-734 measures a user-selectable analog quantity and
produces a dc current between –1.2 and +1.2 mA that is proportional to the
measured value.
Analog outputs provide ±0.25% accuracy for the following quantities;
xx_RMS, xx_AVG, xx_U, all Demand/Peak, Energy, and Max/Min.
Table 8.6 describes each analog output setting (xx = 01–04) When AOxxAQ is
set to OFF, all other settings are hidden.
Figure 8.16 illustrates an example in which we set the SEL-734 analog output
AO01 to report instantaneous three-phase real power (MW3) to a remote
terminal unit (RTU). The RTU expects a ±1 mA input from the SEL-734.
Figure 8.16 Example SEL-734 Connected to an RTU
For our example, we determine that our load has a maximum delivered power
of 1000 kW and maximum received power of 1000 kW. The SEL-734 reports
three-phase real energy as plus (+) for delivered and minus (–) for received
power. We therefore set Analog Quantity Low (AO01AQL) to –1 MW and
Analog Quantity High (AO01AQH) to +1 MW. Next, we establish output
Table 8.6 Analog Output Settings
Setting Name Setting Range Description
AOxxAQ OFF, Valid Analog Quantities Input. Select any valid analog quantity.
See Appendix H: Analog Quantities for
a list of all applicable quantities.
AOxxAQL –2147483647.000 to
2147483647
Input limit. Sets the measured value
that will create the minimum current
output for the selected analog quantity
in primary units.
a
a
Analog quantities are scaled as follows: energy values are in mega units, voltages are in kilo
units, and currents are in units.
AOxxAQH –2147483647.000 to
2147483647
Input limit. Sets the measured value
that will create the maximum current
output for the selected analog quantity
in primary units.
a
AOxxL –1.200 to 1.200 mA Output limit. Specifies the minimum
output current value representing the
setting AOxxAQL.
AOxxH –1.200 to 1.200 mA Output limit. Specifies the maximum
output current value representing the
setting AOxxAQH.
SEL-734
RTU
AO01
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