Virtual signals
Virtual signals can used as signals in Circuit networks. They can be outputted by all devices that can send signals to the circuit network. If a circuit network contains virtual signals, they act like a normal item signal, so you can perform comparisons and arithmetical operations.
Containing signals
Currently Factorio has 45 virtual signals:
- numbers 0-9
- letters A-Z
- colored (red, green, blue, yellow, magenta, cyan, white, gray, black)
Usage
Virtual signals are useful to control devices if the control not depend on items (e.g. if you want to have the robot count as signal). They also are used as output by Arithmetic combinators, where two amounts of items are processed and you can't decide which item is the output.
Special signals
There are also some logic signals in Factorio which are accessible by clicking certain signal slots on devices. They have special functions to control information with multiple signals. These three signals are:
- Everything (red)
- Anything (green)
- Each (yellow)
Everything
- As input
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The "Everything" signal works like a logical AND. It can only be used as the left term of the circuit condition. The condition will only be true if the condition is true for all signals the device receives. Be careful with signals with amount 0, because these signals will not considered by "Everything".
If the decider combinator output is set as "Input count" and not "Everything", there will be no output even if the condition is true.
- As output
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If the condition is true, all input signals are outputted, either with amount 1 or with their input amount.
Anything
- As input
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It works similar than "Everything", but the condition is true if the condition for at least one input signal is true (logical OR).
Each
- As input
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The "Each" signal also performs the operation for all input signals, but the condition is not true or false once, but true or false for each input signal individually.
If the output is "1" and not "Each" (decider combinators only), the signal will only be outputted if at least one condition is true. If the output is "Input count" and not "Each", all amounts of input signals whose condition is true or (for arithmetic combinators) the results of mathematical operations for each input signal are summed and outputted.
- As output
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The "Each" signal can only be set as output if the left input signal is also "Each". A decider combinator outputs only the input signals whose condition is true. An arithmetic combinator ouputs each input signals with an amount that is the result of the operation.