Woodward AtlasPC, Hardware Manual

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Manual 85586V1 AtlasPC Digital Control, Vol. I
Woodward 93
Speed Bias Output
The Speed Bias output is configurable for 4–20 mA with a full scale range of 0–
24 mA, or as a ±3 V, 0–5 V, or PWM voltage output. When used as a PWM
output, the PWM frequency is 500 Hz. Configuring the output requires wiring and
application software configuration. This output is isolated from the rest of the
control system, to prevent ground loops when connecting the PowerSense board
to other controls.
Configuration Notes
•
Refer to Figures 8-11 and 8-12 for Speed Bias Output wiring.
•
The Speed Bias output must be configured for the correct type, 4–20 mA or
the voltage type in the application software.
•
See the specifications section for the maximum output load.
•
The output does not contain fault detection. If it is necessary to detect
failures, then the device that is driven by the analog output, for example an
actuator driver, must contain reference failure detection.
•
The output cannot be used as a voltage output and a current output at the
same time.
Atlas
21
22
23
+
4-20 mA
interface to
speed control
+15 Vdc
(isol)
24
19
SC
20
GND
(isol)
Figure 8-11. Wiring Example–Speed Bias Output Interface
(to the PowerSense Board configured for 4–20 mA)