modified function block (Adafruit_PWM_mod) for raspberry Adafruit PWM board

1) to use this function block install in the device-repository the "500_0000 0004_4.4.0.1.devdesc.xml"

2) install in the library repository the "Raspberry I2C AdafruitPWM_mod.library"

depending on bool variable "_xUseLimitsForRCServo" there are 2 modes existent
_xUseLimitsForRCServo := TRUE : in this mode the fb is used for controlling of RC servos , frequency 50Hz, DC = 1..2ms On
_xUseLimitsForRCServo := FALSE : in this mode the fb is used for controlling free PWM mod
uisetfrequency possible from 1 upto 1000Hz, DC possible from 0..100 (%)

Sample GVL List :
VAR_GLOBAL
x_0FreeMode_1ServoMode : BOOL := TRUE; // RC Servo Mode is selected
uiSetFrequency : UINT := 50; // frequency 50 Hz
MAXPWM_RCMODE : LREAL := 2.0; // max DC = 2.0 ms
MINPWM_RCMODE : LREAL := 1.0; // min DC = 1.0 ms
lr_SetpointCannel_0 : LREAL := 1.5; // setpoint 0 default = 1.0 ms
lr_SetpointCannel_1 : LREAL := 1.5; // setpoint 1 default = 1.0 ms
lr_SetpointCannel_2 : LREAL := 1.5; // setpoint 2 default = 1.0 ms
lr_SetpointCannel_3 : LREAL := 1.5; // setpoint 3 default = 1.0 ms
END_VAR

Sample Program block :

// Settings for the fb
Adafruit_PWM_mod._freq := uiSetFrequency; // setpoint frequency
Adafruit_PWM_mod._xUseLimitsForRCServo := x_0FreeMode_1ServoMode; // select RC Servo Mode
Adafruit_PWM_mod.axEnable[0] := TRUE; // enable channel 0
Adafruit_PWM_mod.axEnable[1] := TRUE; // enable channel 1
Adafruit_PWM_mod.axEnable[2] := TRUE; // enable channel 2
Adafruit_PWM_mod.axEnable[3] := TRUE; // enable channel 3
Adafruit_PWM_mod._alrMin[0] := MINPWM_RCMODE; // minimal DC RC Mode
Adafruit_PWM_mod._alrMin[1] := MINPWM_RCMODE; // minimal DC RC Mode
Adafruit_PWM_mod._alrMin[2] := MINPWM_RCMODE; // minimal DC RC Mode
Adafruit_PWM_mod._alrMin[3] := MINPWM_RCMODE; // minimal DC RC Mode
Adafruit_PWM_mod._alrMax[0] := MAXPWM_RCMODE; // maximal DC RC Mode
Adafruit_PWM_mod._alrMax[1] := MAXPWM_RCMODE; // maximal DC RC Mode
Adafruit_PWM_mod._alrMax[2] := MAXPWM_RCMODE; // maximal DC RC Mode
Adafruit_PWM_mod._alrMax[3] := MAXPWM_RCMODE; // maximal DC RC Mode

// signal to output 0
IF x_0FreeMode_1ServoMode = TRUE // RC servo mode or free mode ?
THEN
Adafruit_PWM_mod.alrPWM[0] := LIMIT(0.0,(lr_SetpointCannel_0/100.0),1.0); // alrPWM = 0.0..1.0 ms (added to _alrMin )
ELSE
Adafruit_PWM_mod.alrPWM[0] := lr_SetpointCannel_0; // alrPWM = 0..100% DC in free mode
END_IF
// signal to output 1
IF x_0FreeMode_1ServoMode = TRUE // RC servo mode or free mode ?
THEN
Adafruit_PWM_mod.alrPWM[1] := LIMIT(0.0,(lr_SetpointCannel_1/100.0),1.0); // alrPWM = 0.0..1.0 ms (added to _alrMin )
ELSE
Adafruit_PWM_mod.alrPWM[1] := lr_SetpointCannel_1; // alrPWM = 0..100% DC in free mode
END_IF
// signal to output 2
IF x_0FreeMode_1ServoMode = TRUE // RC servo mode or free mode ?
THEN
Adafruit_PWM_mod.alrPWM[2] := LIMIT(0.0,(lr_SetpointCannel_2/100.0),1.0); // alrPWM = 0.0..1.0 ms (added to _alrMin )
ELSE
Adafruit_PWM_mod.alrPWM[2] := lr_SetpointCannel_2; // alrPWM = 0..100% DC in free mode
END_IF
// signal to output 3

IF x_0FreeMode_1ServoMode = TRUE // RC servo mode or free mode ?
THEN
Adafruit_PWM_mod.alrPWM[3] := LIMIT(0.0,(lr_SetpointCannel_3/100.0),1.0); // alrPWM = 0.0..1.0 ms (added to _alrMin )
ELSE
Adafruit_PWM_mod.alrPWM[3] := lr_SetpointCannel_3; // alrPWM = 0..100% DC in free mode
END_IF
)
FUNCTION_BLOCK AdafruitPwm_mod EXTENDS i2c
VAR_INPUT
_xUseLimitsForRCServo : BOOL := TRUE;( True = RC Servo Mode, , FALSE = Free PWM Mode )
_freq: UINT := 50; ( frequency [Hz] )
alrPWM : ARRAY[0..15] OF LREAL; ( _alrMin.._alrMax = xms..yms Signal On in RC Servo Mode , 0..100 = 0..100% %DC in free PWM Mode )
axEnable : ARRAY[0..15] OF BOOL := [4(TRUE)]; ( Bit x = TRUE: set PWM output channel x; FALSE: do not modify output signal of channel x )
_alrMin: ARRAY[0..15] OF LREAL := [16(0.7)]; ( minimum time [ms], the pulse is ON for RC Servo Mode )
_alrMax: ARRAY[0..15] OF LREAL := [16(2.2)]; ( maximum time [ms], the pulse is ON for RC Servo Mode )
END_VAR
VAR_OUTPUT
END_VAR
VAR
( no longer supported, use axEnable instead
_usiUsedOutputs: USINT := 16; ( number of used outputs ) )
_usiSMAxes: USINT := 0; ( internal counter for registered SM axes )
_rPeriod : LREAL; ( Period [ms], time between two rising edges *)
_alrOldPWM : ARRAY[0..15] OF LREAL;
_lrOldFreq : LREAL;
END_VAR
VAR_TEMP
i, usi : USINT;
END_VAR