2.2.6 Priority of input sources
Each controller can receive inputs from a variety of sources. The rules for when a source can be used, as well as how the controller
handles conflicting inputs, are described below.
Digital input functions
Digital input functions can be activated by wiring connected to hardware, Modbus and/or CustomLogic coils.
Rules for digital input functions:
1. If a digital input function is assigned to hardware, you cannot assign that function to a CustomLogic coil (that is, a normally open
or normally closed coil).
2. If a digital input function is assigned to a CustomLogic coil, you cannot assign that function to hardware.
CAUTION
If you try to assign a digital input that is already assigned to a CustomLogic coil to hardware, it may seem possible.
However, if you refresh the hardware view, you will see that the input has not been assigned.
3. For pulse functions:
a. If there is a command from Modbus, then the controller can activate the function. This is true even if the function is assigned
to hardware.
b. The controller always responds to the most recent input, without considering the source.
4. For continuous functions:
a. If the function is assigned to hardware: If Modbus sends a command, then the command is not allowed and has no effect.
b. If the function is not assigned to hardware: If Modbus and CustomLogic send conflicting signals, then the controller uses the
CustomLogic signal.
INFO
Commands from display unit push-buttons have the same priority as wiring connected to hardware.
Analogue input functions
Analogue input functions can receive inputs from wiring connected to hardware, Modbus, and/or CustomLogic coils.
Rules for analogue input functions:
1. If the analogue input function is assigned to hardware, Modbus can only read the input value. Modbus and CustomLogic cannot
modify the input value.
2. If the analogue input function is not assigned to hardware, Modbus and CustomLogic can modify the input value.
3. If Modbus and CustomLogic send conflicting signals, then the controller uses the CustomLogic signal.
2.3 Control and modes
2.3.1 Introduction
The controllers use control types and modes to distinguish between fully automatic operation and various degrees of operator (or
external) control.
Table 2.3
Controller types and modes
Type
PMS control
AUTO mode
SEMI mode
SWBD control
Push-button
GENSET controller
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EMERGENCY genset controller
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DESIGNER'S HANDBOOK 4189340911K UK
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