外部安全电路

    为了确保整个系统能在安全状态下可靠工作，避免由于外部电源发生故障、PLC出现异常、误操作以及误输出造成的重大经济损失和人身***事故，PLC外部应安装必要的保护电路。

    （1）急停电路。对于能使用户造成伤害的***负载，除了在控制程序中加以考虑之外，还应设计外部紧急停车电路，使得PLC发生故障时，能将引起伤害的负载电源可靠切断。

    （2）保护电路。正反向运转等可逆操作的控制系统，要设置外部电器互锁保护；往复运行及升降移动的控制系统，要设置外部限位保护电路。

    （3）可编程控制器有监视定时器等自检功能，检查出异常时，输出全部关闭。但当可编程控制器CPU故障时就不能控制输出，因此，对于能使用户造成伤害的***负载，为确保设备在安全状态下运行，需设计外电路加以防护。

DEC Vax MicroVax 3100 KA41-D MV3100/20E 54-18858-01 I/O

Transtech DSP TPMB2 PCI Card Multi-PMC Carrier/Tester 

DEC 54-24289-01Vide?o Card 54-24291-02 70-32301-01 ZLXP1

Tape Drive SCSI Wangtek 5525ES 525 525MB QIC 33777-024

***s DEC VAX PDP ClearPoint DCME-M30DAU/32 Memory Card

Amstrad PCW EME-232 CF-2 Floppy Drive PCW9512 Z80265 

Motherboard Dual Slot1 P3 Intel E186194 750780-606 133

SeaLevel ACB-530 4111 Rev.C ISA RS-530 RS-422/485 449

PIKA PIK8855 Daytona/16P8L ISA Card PIK-028-00234 

Hard Drive SCSI DEC RZ2330-29999-01 B01 C0LPXA 3100D

Intellicon D-Flex ISA RS-485 RS-422 RS485 Dual Serial

BULK LOT of 6 Sun Ultra 10 375-0009 Motherboard 300 MHz

39P8107 IBM 1GB 2x512MB 133MHZ 168-PIN PC133 ECC SDRAM

SDL WANic-500 PCI Card 6-0064 with RS-422 6-0072 R***

Diamond SupraSonic 1 meg Modem HSA 236-40001-001SU?P2740

Intel Industrial Slot1 Motherboard 754558-303 E139761

Intel VS440FX Motherboard AA 655391-406 AA655391-406

Tiara LANcard A15-00414-0000 ARCnet 8-bit ISA PC/ XT/AT

Digiboard PC/4e ISA 50000343 RS-232 4 RS232 Card RevH

Hard Drive SCSI IBM DPES-31080 46H6132 1080 MB 80-pin

Hard Drive SCSI Seagate ST118273W 9J5002-026 5764 68pin

Hard Drive SCSI IBM DORS-32160 85G3683 2160MB 50pin

Hard Drive SCSI Quantum Atlas IV KN09L011 01-E 9.1GB 68

Tape Drive SCSI DAT Tecmar WangDAT 3900 1390000-005A

Hard Drive IDE Conner CP-3104 C13Y6S SG3 9017 JXE1F

Hard Drive SCSI Seagate XP34300W CS4L491-01-C-C RevB

Hard Drive SCSI Quantum 270S TB25S026 04-E 655-0186-A

Hard Drive SCSI Quantum Fireball TM 3200S TM32S012 02-C

Hard Drive SCSI Quantum M***erick ProDrive 540S MV54S011

Hard Drive SCSI Quantum 540S F***S029 r02-G 655-0272-A

Hard Drive SCSI Micropolis 4110 TR0031-01-3 136382-01-7

Hard Drive IDE Quantum 425i AT PD425A Vintage Disk

Tape Drive SCSI IBM 7208-011 Exabyte 870010-200 HH CTS

Motherboard Socket7 Gigabyte GA586VX Rev3.36 430VX 3ISA

Atalla Terminal 106317 Network Security SignMaster 

Hard Drive SCSI 50-pin 772X6363 IBM 

MicroFlex DAP PC9000 Handheld Computer PC-9000 DOS 3.31

Quantum ATL ValueLoader VS-80 VS80 DLT Tape Library 

HSZ50 70-32836-01.C02 54-23883-05 & BG-QZ0ZB-BA H885-AA

90-0050-04/C 90-0071-10/D Newbridge Alcatel Control Crd

Hard Drive SCSI Fujitsu MAP3367NP Ultra320 CA06200-B160

Hard Drive SCSI HP C3010-60062 2GB FH 

Hard Drive IDE Hitachi Deskstar HDS722540VLAT20 08K0461

Hard Drive IDE Hitachi Deskstar HDS722540VLAT20?/08K0461

Hard Drive IDE WD100 WD100EB-00BHF0 10GB 16JAN2001