abs是absolute的简写，表示了地址优先级的设置是以绝对地址优先还是以符号优先，即abs/sym。
abs<5.2表示按Step7 V5.1 SP6（低于5.2版本）
也可在block属性中设置符号优先，则状态变为sym<5.2，如下图：




参考帮助文件：
Abs/Sym < 5.2
Abs/Sym > 5.2

This indicates which address priority is set for the properties of the block folder.
The address priority determines whether absolute or symbolic addresses should be used as standard in the block after the symbol table has been modified.
Abs/Sym < 5.2 refers to the STEP 7 versions up to V5.1 SP6 (incl). Abs/Sym > 5.2 refers to the STEP 7 versions as of V5.2.