Siemens S5 Instructions

Hi, I am working with an old S5 program and need some information on a couple of instructions or a reference that details the operation of these instructions:

U, UN, L, LC

Can anyone advise? Regards, M

I guess these are german mnemonics

U = And
UN = And Not
LC - Load Current Counter/Timer Value into AR1 as BCD
L - Load

Thanks for the assist.