User Manual

Function blocks

223

08/04 AWB2528-1423GB

• Analog inputs IA01 to IA04

– IA01: terminal I7

– IA02: terminal I8

– IA03: terminal I11

– IA04: terminal I12

• Analog output QA01

• Actual value

… QV> of another function block

Displaying the parameter set in the PARAMETERS

• + Access enabled

• – Access disabled

Contacts

PW01E1 to PW02E1, the minimum on duration or the

minimum off duration was undershot.

Coils

PW01EN to PW02EN, enable coil.

Memory requirement of the function block

The pulse width modulation function block requires 48 bytes

of memory plus 4 bytes per constant on the function block

input.

Function of the pulse width modulation function

block

The manipulated variable at function block input >SV is

converted to a pulse string with a constant period duration.

The pulse width is proportional to the manipulated variable

SV. The period duration and the minimum on duration can

be selected as required within the specified limits.

The function block causes a direct output of the pulse to the

corresponding output. The output image of the circuit

diagram is always updated.

The pulse width modulation function block must be

enabled so that it can work. Coil PW..EN is active. If coil

PW..EN is not active, the entire function block is

deactivated and reset. The output value is set to zero.