Woodward 505XT, Инструкция по установке и эксплуатации

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Manual 35018V1 505XT Digital Control System for Steam Turbines
Woodward 87
Invert Auxiliary Input
Depending on the control action required, the Auxiliary PID’s input signal can be inverted. If a decrease in
inlet control valve position is required to increase the Auxiliary process signal, program the ‘INVERT AUX
INPUT’ setting to ‘YES’. An example of this control action would be when the Auxiliary PID is configured
to control turbine inlet steam pressure. To increase turbine inlet steam pressure, inlet control valve
position must be decreased.
Auxiliary Set Point
The Auxiliary set point can be adjusted from the 505 keypad, external contacts, Modbus/OPC commands,
or through a 4–20 mA analog input. A specific setting can also be directly entered from the 505 keypad or
through Modbus commands.
The Auxiliary set point range must be defined in the Configuration mode. Program settings ‘Minimum
Auxiliary Setpoint’ and ‘Maximum Auxiliary Setpoint’’ define the range of the Auxiliary set point and
control.
When a raise or lower Auxiliary Set Point command is issued, the set point moves at the programmed
‘Auxiliary Setpoint Rate’ setting. If a Auxiliary raise or lower command is selected for longer than three
seconds, the Auxiliary set point will move at three times at the fast rate which is three times the Auxiliary
set point rate. The Auxiliary set point rate, fast rate delay, and fast rate can all be adjusted in the Service
mode.
The shortest length of time a set point will move for an accepted raise or lower command is 40
milliseconds (120 milliseconds for a Modbus command
A specific set point may also be directly entered from the 505 keypad or through Modbus/OPC
communications. When this is performed, the set point will ramp at the ‘Auxiliary Setpoint Rate’ (as
defaulted in Service mode).
To “enter” a specific set point from the 505 Display use the following steps:
1. From the HOME page go to the Auxiliary Control page
2. Press the Commands button until ‘Entered Setpoint’ appears
3. Select ‘Entered Setpoint’ and a pop-up will appear
4. Press Enter from the Navigation cross and the pop-up value will highlight
5. Adjust the value with the Adjust keys or enter a value from the keypad
6. Press Enter again when desired value has been entered
7. The value in the pop-up will be accepted, if it is invalid a message will appear
8. Select the GO button to ramp the setpoint to this entered value
Refer to Volume 2 of this manual for further information on Service mode and on-line tunables. All
pertinent auxiliary control parameters are available through the Modbus links. See Chapter 6 for a
complete listing of Modbus parameters.
Remote Auxiliary Set Point
Remote Aux Set Point
The Auxiliary set point can be positioned through an analog signal. Optionally, one of the 505’s analog
inputs can be programmed to position the Auxiliary PID set point. This allows the Auxiliary set point to be
positioned remotely by a process control or distributed plant control system.
The Remote Auxiliary Set Point (RAS) range is determined by the programmed Analog input’s 4 mA and
20 mA settings. The Remote Auxiliary Set Point range is tunable in the Service mode, but cannot be set
outside of the min and max Auxiliary Set Point settings.