PWM_M241: Command a Pulse Width Modulation Signal
The Pulse Width Modulation function block commands a pulse width modulated signal output at the specified frequency and duty cycle.
This illustration is a Pulse Width Modulation function block:
To see the general representation in IL or ST language, refer to the Differences Between a Function and a Function Block chapter.
This table describes the input variables:
|
Inputs |
Type |
Comment |
|---|---|---|
|
EN_Enable |
BOOL |
TRUE = authorizes the PWM enable via the IN_EN input (if configured). |
|
F_Enable |
BOOL |
TRUE = enables the Pulse Width Modulation. |
|
EN_SYNC |
BOOL |
TRUE = authorizes the restart via the IN_Sync input of the internal timer relative to the time base (if configured). |
|
F_SYNC |
BOOL |
On a rising edge, forces a restart of the internal timer relative to the time base. |
|
HighPrecision |
BOOL |
If FALSE (the default), the duty cycle is specified in units of 1%. See Duty below. If TRUE, the duty cycle is specified in units of 0.1%. NOTE: The value of the Duty parameter is automatically updated to 0...100 or 0...1000 according to the value selected. |
|
Frequency |
DWORD |
Frequency of the Pulse Width Modulation output signal in tenths of Hz (range: 1 (0.1 Hz)...200,000 (20 kHz)). |
|
Duty |
UINT |
Duty cycle of the Pulse Width Modulation output signal, in units of 1% (range: 0...100 (0%...100%)). NOTE: If the HighPrecision input is set to TRUE, the duty cycle is in units of 0.1% (range: 0...1000 (0%...100%)). |
This table describes the output variables:
|
Outputs |
Type |
Comment |
|---|---|---|
|
InFrequency |
BOOL |
TRUE = the Pulse Width Modulation signal is currently being output at the specified frequency and duty cycle. FALSE = oThe required frequency cannot be reached for any reason. oF_Enable is set to False. oEN_Enable is set to False or no signal detected on the physical input EN Input (if configured). |
|
Busy |
BOOL |
Busy is used to indicate that a command change is in progress: the frequency is changed. Set to TRUE when the Enable command is set and the frequency or duty is changed. Reset to FALSE when InFrequency or Error is set, or when the Enable command is reset. |
|
Error |
BOOL |
TRUE = indicates that an error was detected. |
|
ErrID |
When Error is set: type of the detected error. |
NOTE: When the required frequency cannot be reached for any reason, the InFrequency output is not set to TRUE, but Error stays to FALSE.
