SFB4帮助中的
If you want instances of this SFB to be initialized following a warm restart, you must call SFB 4 with PT = 0 ms in OB100. If instances of this SFB are located within another block, you can reset these instances, for example, by initializing the higher-level block.

应该如何理解！SFB调用的是哪一个DB