Hamilton Sundstrand Company Gas Fuel Metering Valve HFG2.0 - Manual (Page 27)

Discrete Outputs
The discrete outputs are +24 VDC. They are electrically isolated up to 500
VAC. See Figure 1-16 for a typical discrete output alarm connection.
CONTROLLER DISCR ETE INPUT
HFG2.0 DISCRETE OUTPUT
FAULT RTN [WH T/ORN]
OVERTEMP RTN [WH T/BLK]
FAULT ALARM [ORN]
OVERTEMP ALARM [BLK]
CONTROLLER DISCRETE INPUT
HFG2.0 DISCRETE OUTPUT
FAULT ALARM [ORN]
OVERTEMP ALARM [BLK]
FAULT RTN [WHT/ORN]
OVERTEMP ALARM RTN [WHT/BLK]
Figure 1-16. Typical Discrete Output Alarm Connections
RS232 Serial Communications Interface
Signal levels for the serial communications input and output are per
RS232 standards. See Figure 1-17 for a typical RS232 serial interface
connection. See Table 1-5 for computer COM port pin-outs for RS232.
Figure 1-17. Typical RS232 Serial Interface Connection
INSTALLING THE HFG2.0 21