描述
现在工业上经常使用的PLC种类繁多，对于低端的PLC而言，梯形图指令大同小异，对于中高端机，如S7-300，许多程序是用语言表编的。实用的梯形图必须有中文符号注解，否则阅读很困难，看梯形图前如能大概了解设备工艺或操作过程，看起来比较容易。
若进行电气故障分析，一般是应用反查法或称反推法，即根据输入输出对应表，从故障点找到对应PLC的输出继电器，开始反查满足其动作的逻辑关系。经验表明，查到一处问题，故障基本可以排除，因为设备同时发生两起及两起以上的故障点是不多的。
Allen Bradley 1388B-AV40 Allen Bradley Bulletin 1388 20A DC Servo Drive
Allen Bradley 1389-AA09-A01 Allen Bradley 3.3Kw Servo Drive
Allen Bradley 1389-PAT10 Allen Bradley Bulletin 1389 Power Supply
Allen Bradley 1389-PAT10HR Allen Bradley Bulletin 1389 Power Supply
Allen Bradley 1391-AA15 Allen Bradley 1391 5.5Kw Servo Drive
Allen Bradley 1391-DES45-D1 Allen Bradley 1391 45A Axis Servo Drive
Allen Bradley 1391B-AA15 Allen Bradley Bulletin 1391 5.5Kw Servo Drive
Allen Bradley 1391B-AA45 Allen Bradley Bulletin1391 14KW Servo Drive
Allen Bradley 1394-AM03 Allen Bradley Bulletin 1394 2Kw AC Servo Drive
Allen Bradley 1394-AM04 Allen Bradley Bulletin 1394 3KW AC Servo Drive
Allen Bradley 1394-AM05 Allen Bradley Bulletin 1394 5Kw AC Servo Drive
Allen Bradley 1394-AM07 Allen Bradley 1394 AC Servo Controller
Allen Bradley 1394-SJT05-A Allen Bradley 1394 Digital Servo With Analog Contr
Allen Bradley 1394-SJT05-C-RL Digital Servo Controller (5kW Standard Version)
Allen Bradley 1394-SJT05-T Allen Bradley 1394 5Kw Servo Controller
Allen Bradley 1394-SJT05-T-RL Digital Servo Controller (5kW Turbo Version)
Allen Bradley 1394-SJT10-T-RL Allen Bradley 1394 Digital Servo Controller
Allen Bradley 1394C-AM03 Allen Bradley Bulletin 1394 2KW AC Servo Drive
Allen Bradley 1394C-AM50 Allen Bradley Bulletin 1394 10 KW AC Servo Drive
Allen Bradley 1394C-SJT05-D Allen Bradley Bulletin 1394 Digital Servo Control
Allen Bradley 1394C-SJT05-T Allen Bradley Bulletin 1394 Digital Servo Control
Allen Bradley 1395-A66N-C1-PZ Allen Bradley 1395 5.6Kw DC Drive
