Manual 35018V1
505XT Digital Control System for Steam Turbines
Woodward
44
Figure 2-10. Actuator Output Block Diagram
Hardware - Discrete Inputs
This control provides an isolated group of (20) discrete input channels for use with +24 V (dc) signals. An
isolated Contact Power voltage supply of +24 V (dc) is provided to use with the discrete inputs. This
supply includes short-circuit and over-voltage protection. Note: Do not use the Contact Power output to
power any other devices.
Features
(20) Discrete Input Channels for +24 V (dc) signals
+24 V Contact Power with short-circuit and diode protection
Isolated power and discrete input group
Woodward GAP block, diagnostics, and configuration support
GAP configurable update rates of 5 ms to 160 ms
Time-stamping capability (1 ms)
Table 2-11. Specifications (DI)
Number of Channels
20
DI Input Low State
(0 to 8) V (dc)
DI Input High State
(16 to 32) V (dc)
DI Input Current
< 5 mA per channel
DI Input Impedance
25K approx
DI Hardware Filter
1.0 ms approx at room temp
DI Channel Isolation
0 V channel to channel
500 Vrms to EARTH and all other I/O
DI Overvoltage
Overvoltage to 36 V (dc) for inputs
Contact Power Output
24 V ±14 %, 150 mA (max), short circuit & diode
protected
Contact Power Isolation
500 Vrms to EARTH and all other I/O
Figure 2-11. Discrete Input Block Diagram