可編程控制器PLC運行時可能會出現死機的情況，這給工業生產造成不可預估的損失，因此，先要了解PLC死機的原因，針對原因進行排查，軟件或硬件錯誤都有可能導致PLC死機，下面分別進行介紹：

    1、硬件方面 

    （1）I／O竄電，PLC自動偵測到I／O錯誤，進入STOP模式。 

    （2）I／O損壞，程序運行到需要該I／O的反饋信號，不能向下執行指令。 

    （3）擴展模塊(功能型，如A／D)線路干擾或開路等。 

    （4）電源部分有干擾或故障。 

    （5）PLC的連接模塊及地址分配模塊出故障。 

    （6）電纜引起的故障。 

    2、軟件方面 

    （1）觸發了死循環。 

    （2）程序改寫了系統參數區的內容，卻沒有初始化部分。 

    （3）保護程序啟動：硬件保護、限制使用時間(針對貨款收回) 

    （4）數據溢出，步長過大、看門狗 (可修改DOG時間)動作。
ALLEN BRADLEY 1747-L20G 20 I/O FIXED HARDWARE 
ALLEN BRADLEY 1747-L20L 20 I/O FIXED HDWR STYLE, 12 DC SOURCE IN W/ HSC & 8 TRANS. SINK OUT, AC LINE PWR, 
ALLEN BRADLEY 1747-L20R 20 I/O FIXED HARDWARE 
ALLEN BRADLEY 1747-L20P 20 I/O FIXED HARDWARE 
ALLEN BRADLEY 1747-L20R 20 I/O FIXED HARDWARE 
ALLEN BRADLEY 1747-L30A 30 I/OFIXED HDWR STYLE, 18 120 V AC IN & 12 RELAY OUT, AC LINE PWR, 
ALLEN BRADLEY 1747-L30B 30 I/OFIXED HDWR STYLE, 18 120 V AC IN & 12 RELAY OUT, AC LINE PWR, 
ALLEN BRADLEY 1747-L40A 40 I/OFIXED HDWR STYLE, 18 120 V AC IN & 12 RELAY OUT, AC LINE PWR, 
ALLEN BRADLEY 1747-L40B 40 I/O FIXED HDWR STYLE 24 120 V IN & 16 TRIAC OUT, AC LINE PWR, 
ALLEN BRADLEY 1747-L40C 40 I/O FIXED HDWR STYLE 24 DC SINK IN W/HSC & 16 RELAY OUT, AC LINE PWR 
ALLEN BRADLEY 1747-L40E 40 I/O FIXED HDWR STYLE 24 DC SINK IN W/HSC & 16 RELAY OUT, AC LINE PWR 
ALLEN BRADLEY 1747-L40F 40 I/O FIXED HDWR STYLE 24 DC SINK IN W/HSC & 16 RELAY OUT, AC LINE PWR 
ALLEN BRADLEY 1747-L40L 40 I/O FIXED HDWR STYLE 24 DC SINK IN W/HSC & 16 RELAY OUT, AC LINE PWR 
ALLEN BRADLEY 1747-L40P 40 I/O FIXED HDWR STYLE 24 DC SINK IN W/HSC & 16 RELAY OUT, AC LINE PWR 
ALLEN BRADLEY 1747-L511 SLC 5/01 CPU, 1K USR MEMORY IEMENS SIRIUS 3RT1045-1AN24 3RT1 045-1AN24 E: 05 -OV...

ABB 6173AG101500 6173 AG-101-500

ABB SACE TMAX T1B 160 1SDA050889R0001

Siemens Simatic 6GK1415-2AA01 E-Stand: 8

Siemens Simatic 6GK1415-2AA01 E-Stand: 9

Telemecanique LC1D8011B7 LC1 D8011B7 - Id.-No. 023190

Siemens Wendestarter 3TD4202-0AP0 3TD42 02-0AP0

Mettler TYPE CL 240 BCD Interface

Siemens Simatic S5 6ES5 441-4UA13 6ES5441-4UA13

Siemens 7PA2622 7PA2622-0AA00 60VDC -used-

Siemens Sitop 6ES1436-3BA00 6ES1 436-3BA00

Siemens 3RK1300-1DS01-1?AA0 3RK1 300-1DS01-1AA0

Telco Space Guard Controller Type: SGC11A300

Phoenix Contact PSM-EG-RS232/RS?422-P/4K

E.Dold&S?hne BD9080.12/001 BD 9080 12 001 3AC500V

Euchner TZ1RE024PG 046155 Sicherheitsends?chalter

Siemens Sirius 3RT1044-1AP00 bzw. 3RT1 044-1AP00 - E-St...

Euchner RGBF02D16-502 012375 Nockenendschalt?er

Euchner GSBF02R12-502 011282 Rollenendschalt?er