当FOR_ LOOP使能激活，将保存START(循环初值)、END(循环终值)、和INC(增操作)操作数，计算出梯级逻辑在FOR_ LOOP和END_ FOR这两个指令之间循环的次数。在执行循环操作的过程中改变START和END操作数不影响操作。当END_FOR使能激活,程序循环终止，能流直接跳转到END_FOR指令后面的语句。
TEXAS INSTRUMENTS PLC 5TI-1020-1 USPP 5TI10201
BARBER COLMAN MSC-IOC NSFP MSCIOC
ADEPT TECH 10300-16500 USPP 1030016500
ADEPT TECH 10300-16600 USPP 1030016600
ALLEN BRADLEY 1398-DDM-009-DN NSFP 1398DDM009DN
CINCINNATI MILACRON 3-533-0660G USPP 35330660G
ALLEN BRADLEY 1756-L55M22 USPP 1756L55M22
ALLEN BRADLEY 1756-L55M24 USPP 1756L55M24
CONTROL TECHNIQUES DXE-4120C NSFP DXE4120C
ALLEN BRADLEY 1775-MED USPP 1775MED
SICK OPTIC ELECTRONIC LVS-800-2200 USPP LVS8002200
BAUMULLER BUS20-60/90-30-?001 USPP BUS20609030001
RELIANCE ELECTRIC 0-52806-1 NSFP 0528061
ALLEN BRADLEY 1336-B007-EAD-L?1 USPP 1336B007EADL1
RELIANCE ELECTRIC 0-52806-01 NSFP 05280601
