24This represents the IEC 61131-3 standard, where each variable within an instruction may be “connected” to its own arbitrary tag name. Other programming conventions may differ somewhat. The Allen-Bradley Logix5000 series of controllers is one of those that differs, following a convention reminiscent of structure element addressing in the C programming language: each counter is given a tag name, and variables in each counter are addressed as elements within that structure. For example, a Logix5000 counter instruction might be named parts_count, with the accumulated count value (equivalent to the IEC’s “current value”) addressed as parts_count.ACC (each element within the counter specified as a suffix to the counter’s tag name).