LPTSIGNAL
This function sets a defined output bit in a Centronics interface to a logical high or low level, and can, for example, be used for run-time measurements with an oscilloscope. The function returns the preset state which has been written to the output pin.
FUNCTION LPTSIGNAL: BOOL
VAR_INPUT
PortAddr :UINT;
PinNo :INT;
OnOff :BOOL;
END_VAR
PortAddr: Address of the port which is available for the desired LPT interface;
PinNo: Contains the number of the pin (Pin 0 .. 7 ) which is to be written by the PLC;
OnOff: Contains the state which is to be written to that pin;
Example of calling the function in FBD:
In the example, bit 7 of port 378 (hex) is set to 1.
Requirements
Development environment | Target system type | PLC libraries to include |
---|---|---|
TwinCAT v2.7.0 | PC or CX (x86) | PLCSystem.Lib |
TwinCAT v2.8.0 | PC or CX (x86) | TcSystem.Lib |
TwinCAT v2.10.0 Build >= 1301 | CX (ARM) | TcSystem.Lib |