Hamilton Sundstrand Company Gas Fuel Metering Valve HFG2.0 - Manual (Page 33)

during the RESET command. To reset the HFG2.0, +24 VDC must be
applied across the RESET wires for at least 0.5 seconds in order to reset
the controller and actuator.
DEMAND Signal
The DEMAND signal is a user-provided analog input that is used to
control the position of the valve. The current level of the DEMAND signal
is correlated to the position of the valve within its range. The minimum
Demand signal of 4.0 mA is correlated to the CLOSED (Home) position.
The maximum Demand signal of 20 mA is correlated to the OPEN
(maximum flow) position.
Feedback Signals
The HFG2.0 provides two two-wire feedback signals via the integral
17-wire signal harness. Refer to Figure 1-14 for typical connections. Refer
to the General Specification Summary Table in Section 1.2 for feedback
specification values.
Position Feedback
The HFG2.0 provides analog valve position feedback to the user. This
internally-generated feedback signal is proportional to the valve position.
A signal level of 4 mA represents that the valve is at its CLOSED (Home)
position; while a signal level of 20 mA represents that the valve is at its
maximum span.
Motor Current Feedback
The HFG2.0 provides motor current feedback. This internally-generated
feedback signal is proportional to actuator load. A signal level of 4 mA
represents no load on the actuator; while a signal level of 20 mA is the
maximum load.
CH. 2: UNDERSTANDING THE HFG2.0 27