problem with Cyclic interrupts in S7-300

Hi all, I am working with a PLC S7-300 CPU 315-2DP I programmed an OB32 for sendind data over an ethernet, but when I try to download it to the PLC I get this message: (D20C) OB cannot be copied as the associated priority class does not exist. Unable to copy the block OB32 It is the first interruption I have ever programmed, so I don't know the reason for the error. I just copied the OB32 from the Standard library and programmed what I wanted it to do,Have I missed something. Greetings and Thank you in advance, Ana

Hi,

The number of interrupt OB depends with the CPU type. The CPU 315 has only one: OB 35 (he accepts no OB32). I suggest you change the name of your OB from OB 32 to OB35 and try to download again. Note: don’t forget set the time of the interrupt in the properties of the CPU in Hardware Configuration.