Equipments (Devices) > PLC200 > Program > Hardware

Block that generates a certain number of pulses at the specified output.

Ladder Representation

PULSES_G0

Block Structure

Variable Type	Name	Data Type	Description
VAR_INPUT	EN	BOOL	Block enabling
	OutputNumber	CONST	Selected output
	NumberOfPulses	DWORD	Total number of pulses of the block execution
	Frequency	DWORD DINT	Pulse frequency
VAR_OUTPUT	DONE	BOOL	Output enabling
	Active	BOOL	Indicates that the block is active
	Busy	BOOL	Indicates that another block is using the selected output
	Error	BOOL	Indicates that an error occurred when calling the block
	ErrorID	BYTE	Indicates the error generated
VAR	PULSES_INST_0	PULSES	Instance of access to block structure

Operation

When the EN input is TRUE, the block generates a PWM signal at the output (outputNumber) with the desired frequency (between 0 and 300 kHz) and a constant duty cycle at 50%.

The PWM signal is interrupted when the total number of pulses (Pulses) has been generated.

As long as the number of generated pulses does not reach the Pulses value, the "Active" output remains at high level.

When the Pulses value is reached, the ENO output changes to TRUE.

If the EN input goes to FALSE before reaching the number of Pulses, the PWM generation stops immediately.

The minimum number of pulses that can be generated is two. However, if the number of pulses to be generated is zero, the block will return success.

If this limitation is not observed, no pulse is generated.

NOTE!

If other PWM blocks running use the same output, the one called first will have priority and the "Busy" output is set.

Example in Ladder

PULSES_example01

PULSES_example02

The above example enables a PWM signal in DO1 output with initial frequency 200 Hz and duty cycle of 50%. No type of frequency ramp is performed. In total executing the block, 1000 pulses will be sent to the output. If the block is successfully completed, the DONE output is activated.

Example in ST

The example below displays instructions for applying the example above in ST language.

VAR

start : BOOL := 0 ;

coil : BOOL := 0 ;

pulses : DWORD := 1000;

freq : DWORD := 200;

PULSES_INST_0 : FB_PULSES;

END_VAR

PULSES_INST_0.EN := start;

PULSES_INST_0(

OutputNumber:=1,

numberOfPulses:=pulses,

Frequency:= freq);

coil := PULSES_INST_0.DONE;