Delta Electronics AH500 Operation Manual page 26


A function block is a program element equipped with the operation function. It is similar to a subroutine,
and is a type of POU (Program Organization Unit). It can not operate by itself, and has to be called
through the program POU. After the related parameters are transmitted, the function defined by a
function block is executed. Besides, the final operation result can be sent to the device or variable
used in the superior POU after the execution of the function block is complete.

The setting of passwords by means of ISPSoft provides the secrecy of function blocks for special
businesses. The program inside a function block can not be learned, and the patent of a business will
not be infringed.
8.
Task

The programs can be assigned to 283 tasks at most. Among the 288 tasks, 32 tasks are cyclic tasks,
32 tasks are I/O interrupts, 4 tasks are timer interrupts, 2 tasks are communication interrupts, 1 task is
an external 24 V low-voltage interrupt, and 212 tasks are user-defined tasks.

Users can enable and disable a task during the execution of a program by means of TKON and
TKOFF.
9. Increasing the efficiency of configuring the hardware through an USB cable and ISPSoft

The AH500 series CPU module provides a standard USB 2.0 interface. USB 2.0 increases the data
transfer rate, and decreases the time it takes to download the program, monitor the program and
configure the hardware. Besides, users do not need to buy a communication cable for the CPU
module. They can use a general USB cable to connect to the AH500 series CPU module.
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