IN
Program input
IN
Q
A BOOL program input that passes its value into the FBD diagram.
Read moreFBD reference
FBD block reference
A compact static reference for PLC Portal function blocks: purpose, inputs, outputs, parameters, state, and behavior rules.
BOOL blocksGrouped by purposeInputs, outputs, parameters
IN1
IN2
AND
Q
R
S
RS
Q
IN
TON
Q
CU
R
CTU
Q
The reference describes the current PLC Portal BOOL blocks without changing runtime, compiler, or editor behavior.
Block catalog
Supported FBD blocks
Each card opens a detail page with a typical FBD symbol, port tables, and practical usage notes.
Inputs, outputs, and values
Inputs, outputs, and values
OUT
Program output
IN
OUT
A BOOL program output that writes the result of the FBD diagram.
Read moreINTERNAL_SIGNAL
Internal BOOL variable
IN
INTERNAL_SIGNAL
Q
A named internal BOOL signal for writing or reading intermediate state.
Read moreCONST
Constant BOOL value
CONST
Q
A constant BOOL source that always emits TRUE or FALSE.
Read moreBasic logic
AND
Logical AND
IN1
IN2
AND
Q
Emits TRUE only when both inputs are TRUE.
Read moreOR
Logical OR
IN1
IN2
OR
Q
Emits TRUE when at least one input is TRUE.
Read moreNOT
Logical NOT
IN
NOT
Q
Inverts a BOOL signal.
Read moreXOR
Exclusive OR
IN1
IN2
XOR
Q
Emits TRUE when the inputs are different.
Read moreMemory
Edges
Timers
TON
On-delay timer
IN
TON
Q
Turns Q on after a configured time or scan delay.
Read moreTOF
Off-delay timer
IN
TOF
Q
Keeps Q on after IN disappears until the configured delay expires.
Read moreTP
Pulse timer
IN
TP
Q
Emits a Q pulse for a configured scan or time duration on the IN rising edge.
Read moreCounters
CTU
Count-up counter
CU
R
CTU
Q
Counts rising edges on CU and sets Q when PV is reached.
Read moreCTD
Count-down counter
CD
R
CTD
Q
Counts rising edges on CD down from PV to 0.
Read moreCTUD
Up/down counter
PULSE
DIR
R
CTUD
Q
Counts PULSE rising edges up or down depending on DIR.
Read more