Chapter 7 Function Block and Library *. SM400 is a special auxiliary relay in AH/AS series. It is ON when the CPU module is powered. SM402 initializes forward (an instant RUN is ON). Example of using a symbol whose data type is T_POINTER and a symbol whose data type is C_POINTER Owing to the fact that users can not declare a symbol whose data type is TIMER and a symbol whose data type is COUNTER in a function block in a project for an AH/AS series CPU module, they can send a timer, and a counter to a function block by means of declaring a symbol whose data type is T_POINTER, and a symbol whose data type is C_POINTER in the function block. The function block FB1 has two input pins.
pTMR is a symbol whose data type is T_POINTER, and pCNT is a symbol whose data type is C_POINTER. The caller assigns TMR_1 and CNT_1 to the two pins. (The data type of TMR_1 is TIMER, and the data type of CNT_1 is COUNTER.) In the superior POU, the value of CNT_1 increases by one when X0.0 is turned from OFF to ON. CNT_1 will not be ON until the value of CNT_1 is 10. Owing to the fact that TMR_1 and CNT_1 are assigned to the is ON, TMR_1 (pTMR) measures the time interval. When the value of pTMR is 50, CNT_1 (pCNT) is reset. function block, the state of CNT_1 (pCNT) is judged when the function block is executed.
When CNT_1 (pCNT) Likewise, the present value of pTMR and that of pCNT are not displayed when the online monitoring function is enabled. 7-17