在用户程序执行阶段，PLC 总是按由上而下的顺序依次地扫描用户程序(梯形图)。在扫描每一条梯形图时，又总是先扫描梯形图左边的由各触点构成的控制线路，并按先左后右、先上后下的顺序对由触点构成的控制线路进行逻辑运算
RTP 021-0211-003 Control Board 0210211003
RELIANCE ELECTRIC 45C942 16 Point Input Module
Miscellaneous Boards 63-1162-02 Display Board 63116202
ABB NTDI02 Control Board
Alcatel 3HE00867AA Kit GIGE EX SFP Optics Module – LC N
FCI Fluid Components 0017-A1A1B1A1-4 Power Supply
Precision Scientific 00500901 Analog I/O 500901
Federal Signal 300GC-125-1Z Selectone Speakr 300GC1251Z
Taylor 1100T Mag-Pipe Transmitter 1100TK22000
Miller 132138 4 In 1 Control (Single)
DSP Design 180000.B SPI40.004 B2726 Module Card
Weil-McLain 383-500-658 Auto Ignition 511-330-267
Siemens 6EP1353-0AA00 Power Supply 6EP13530AA0
Reliance Industries 3101 Skyline Beam Clamp 5000 LBS
Southwest Windpower Inverter Board E07201-E E07201E
AMCI iPCE-1-3/D Advanced Micro Controls Encoder 115 VAC
