Data Blocks S-7300

Hi,

DB's are confusing me were they get there signals from unlike the I/O's e.g DB62.DBX6201.O when l check the data block 62 the initual and actual are all false.what triggers this DBX62O1 to be true.when l highlight this and goto it's showing only AND. Please experts l need your help.

I do not have the Simatic Software on this pc but somewhere in your programma there should be

a)

a call-instruction of the DB and after this instruction the DBX will be used as an output-coil.


or

b) the DBX is directly written to as an output-coil:

A I 0.0
= DB2.DBX1.0

Another option is that an operatorpanel is changing the data of the DBX's.

The bits in DB62 are accessed indirectly.

DB62 is called directly in FC62 twice and once it is used as an input parameter on call to FB63 (within FC62).

The datawords are written to indirectly i.e.



I don't like the way the programmer uses L flage within the program, asking for trouble if anyone modifies the program and add's a TEMP before the existing TEMP flags.

Thanks experts l will try that.