mvi69-mcm
输入电路是plc接受开关量、模拟量等输入信号的端口，其元器件质量的优劣、接线方式及是否牢靠也是影响控制系统可靠性的重要因素 。以开关量输入为例，按钮、行程开关的触点接触要保持在良好状态，接线要牢固可靠。机械限位开关是容易产生故障的元件，设计时，应尽量选用可靠性高的接近开关代替机械限位开关。此外，按钮触点的选择也影响到系统的可靠性。在设计电路时，应尽量选用可靠性高的元器件，对于模拟量输入信号来说，常用的有4～20ma、0～20ma直流电流信号；0～5v、0～10v直流电压信号，电源为直流24v.
对于开关量输出来说，plc的输出有继电器输出、晶闸管输出、晶体管输出三种形式，具体选择哪种形式的输出应根据负载要求来决定，选择不当会使系统可靠性降低，严重时导致系统不能正常工作。如晶闸管输出只能用于交流负载，晶体管输出只能用于直流负载。此外，plc的输出端子带负载能力是有限的，如果超过了规定的最大限值，必须外接继电器或接触器，才能正常工作。外接继电器、接触器、电磁阀等执行元件的质量，是影响系统可靠性的重要因素 。常见的故障有线圈短路、机械故障造成触点不动或接触不良。这一方面可以通过选用高质量的元器件来提高可靠性，另一方面，在对系统可靠性及智能化要求较高的场合，可以根据电路中电流异常的情况对输出单元的一些重点部位进行诊断，当检测到异常信号时，系统按程序自动转入故障处理，从而提高系统工作的可靠性。若plc输出端子接有感性元件，则应采取相应的保护措施，以保护plc的输出触点。
allen bradley 1771-ob output module 12-24vdc 8point wow
allen bradley 1771-obd dc output module canada
allen bradley 1771-od16 a isolated 120vac output module
allen bradley 1771-ofe2/b analog output module 1771ofe2
allen bradley 1771-ovn low true output module wow
allen bradley 1771-ow module
allen bradley 1771-oy contact output module
allen bradley 1771-oy ser. c contact output module
allen bradley 1771-p1 power supply
allen bradley 1771-p2 120 vac power supply
allen bradley 1771-p2 power supply
allen bradley 1771-p4r/b power supply module 1771p4r
allen bradley 1771-p4s 120v ac power supply module
allen bradley 1771-p4s b ac power supply module canada
allen bradley 1771-p4s series b 120vac power supply module
allen bradley 1771-p7/c power supply ~
allen bradley 1771-pa/b power supply & 1772-ln3/a plc-2 mini processorlot of 2
allen bradley 1771-rk 1771rk i/o rack keying bands lot of 3 in box
allen bradley 1771-sim 1771sim 8-point discreet module lot of 2
allen bradley 1771-vhsc b very high speed counter module 1771vhscb ab rockwell
allen bradley 1771-wa wiring arm wow canada
allen bradley 1771wh arm field wiring lot of 3 in box
allen bradley 1771-wh wiring arm canada
allen bradley 1772-lv mini processor series b canada
allen bradley 2803-vim1 vision input module ser. a
allen bradley 3ft bus terminator cable model 1771-cx1
allen bradley 4 slot i/o chassis p/n 96815206 b01
allen bradley ac input module cat 1771-1a 10159mo
allen bradley ac output mod 1771-oad tested
allen bradley ac output module 120v series b model cat. no. 1771-0a
allen bradley ac/dc input module
allen bradley basic plc module 1771-db rev a/e
allen bradley cable assembly power supply 1771-cp1 wow
allen bradley cat. 1771-1qc 5-30v dc selectable input module 10156mo
allen bradley cat. 1771-p4s 120v ac power supply mod
allen bradley cat. no. 1771-sim 8-point discrete i/o
allen bradley cat. no 1771-asb d remote i/o adapter
allen bradley cat. no 1771-ife a analog input module 12 bit .
allen bradley cat.no. 1771-kd communication controller module
allen bradley cat 1771-ofe1 b analog output mod. 12 bit voltage outputs w2
allen bradley cat 1771-ofe2 b analog output mod. 12 bit voltage outputs w2
allen bradley co 1771-ic dc input module
allen bradley i/o adapter module 1771-al
allen bradley input module 16 point 120vac 1771-iad
allen bradley input module plc 120v 1771-iad
allen bradley input module plc 120v 1771-iad wow
allen bradley isolated ac output module cat 1771-odc 10160mo
allen bradley isolated input module 1771-id
allen bradley isolated input module 1771-iq16 wow
allen bradley local adapter plc-2 i/o module 1771-al
allen bradley output module 120vac 1771-oa wow
allen bradley output module 8no ser.c 1771-ozc wow
allen bradley output module ttl 1771-og wow
allen bradley plc-2 analog output model 1771-ofc
allen bradley power supply 1771-pa series b
allen bradley power supply module 120 volts 1771-0a
allen bradley selectable dc intput module cat 1771-iqc 5-30v 10161mo
allen bradley series b 120vac power supply module 1771-p4s 96219271b01
allen bradley wiring arm 1771-wc wow
allen bradley 1771-bh
allen bradley 1771-cas
allen bradley 1771-cd
allen bradley 1771-ce
allen bradley 1771-cj
allen bradley 1771-ck
allen bradley 1771-cl
allen bradley 1771-cm
allen bradley 1771-cp
allen bradley 1771-cp1
allen bradley 1771-nc6/a
allen bradley 1771-wa
allen bradley 1771-wb
allen bradley 1771-wc
allen bradley 1771-wd
allen bradley 1771-wg
allen bradley 1771-wh
allen bradley 1771-whf
allen bradley 1771-wn
allen bradley input module1771-ibd/b
allen bradley 1771-db/b basic module pn 95624502
allen bradley alllen bradley 1771-0ad 17710ad ac output module
allen bradley alllen bradley 1771-iad b 120v ac/dc input module
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