Calling the Function Blocks

The frequency output functionality of the DC541 is provided by the block DC541_FREQ_OUT: DC541_FREQ_OUT

Function blocks for the most module functions of DC541-CM are contained in the library DC541_AC500_V11.lib. The library is automatically included into the project and is described in detail in the library documentation DC541_Library: DC541 Library

The Function Block DC541_FREQ_OUT is used to output pulses with a fixed frequency on one channel of the device DC541. It is able to output pulses with a frequency between 0.2 and 2.5 kHz. The pulse jitter depends on the cycle time of the DC541. The pulse length is always a multiple of the cycle time of the DC541.

In case of a presetting of PULSE = 0, the output of pulses is infinite. The pulse output is started with a positive edge at input START. The output is aborted if START = FALSE. A positive edge at input STOP interrupts the pulse output. The output is continued if STOP = FALSE.

If input PULSE > 0, the Function Block outputs the number of pulses specified at input PULSE with the frequency specified at input FREQ on the channel specified at input CH. After the Function Block has output the number of pulses specified at PULSE, the output RDY becomes TRUE.

The device DC541 must be configured as counting device (counter mode). Channel CH must be configured for frequency output.

The Function Block has an integrated visualization which can be used to control all Function Block functions in parallel to the user program, if input EN_VISU = TRUE.

For frequency output, the same configuration example is used as for the time and frequency measurement Usage for Time and Frequency Measurement.