{"id":81,"date":"2016-09-09T00:36:42","date_gmt":"2016-09-09T00:36:42","guid":{"rendered":"http:\/\/taptronics.com\/taptronics\/?p=81"},"modified":"2017-12-01T21:44:29","modified_gmt":"2017-12-01T21:44:29","slug":"poorman-plc-io-board","status":"publish","type":"post","link":"http:\/\/taptronics.com\/taptronics\/poorman-plc-io-board\/","title":{"rendered":"“Poorman” PLC I\/O board"},"content":{"rendered":"

Process or manufacturing plants have PLCs which get signal inputs from mechanical buttons, switches, limit switches and send signal outputs to activate relays, solenoid valves etc.\u00a0 In many cases, they use 24V DC power supply for PLC CPUs\u00a0 and their I\/O modules.\u00a0 This voltage level is used for input modules and deliver 24VDC\u00a0 from output module\u00a0 to turn\u00a0 solenoid valves, coils etc.
\n<\/span><\/p>\n

For non-critical use\u00a0 and ignoring\u00a0 the latency\u00a0 , we can build\u00a0 simple 5V to 24V DC I\/O adapter that can be used with our Microcontrollers to drive 24V DC rating relays and\u00a0 supplying\u00a0 switches\/buttons.<\/span><\/p>\n

 <\/p>\n

\"arduplc\"<\/span><\/p>\n

Don’t get confused with the schematic above . Yes, it works !. The reason there are two “opto couplers”\u00a0 above ( Actually only one opto coupler with two sockets which I will explain later)\u00a0 is that we can use GPIO from our Microcontrollers,\u00a0 AVRs, Arduino boards etc\u00a0 like we intended. For example we can use Pin 1 as input OR as\u00a0 output\u00a0 from the same block diagram above. Let says we have 8 I\/O pins, each pin will go to both red and green block\u00a0 so we just need to focus on our code\/program without worrying which one is for input or output.<\/span><\/p>\n

HOW IT WORKS:<\/strong><\/span><\/p>\n

(See the picture) The main part here is 4N29 opto coupler that can “convert”\u00a0 either 5V DC to 24V DC or from 24V DC to 5V DC. The red square on the picture is a 4N29 socket\u00a0 for output ,and the green one is a socket for input.\u00a0 We have two sockets but we only need one opto coupler IC . When output signal needed , move this\u00a0 IC to the red socket, otherwise we just leave it on green socket. Never put\u00a0 two ICs on both sockets at same time to avoid input\/output conflicts. The inputs\/output devices will be connected to\u00a0 blue square terminal block. Put the relays, bulbs, solenoids, switches,\u00a0 and buttons there .<\/span><\/p>\n","protected":false},"excerpt":{"rendered":"

Process or manufacturing plants have PLCs which get signal inputs from mechanical buttons, switches, limit switches and send signal outputs to activate relays, solenoid valves etc.\u00a0 In many cases, they use 24V DC power supply for PLC CPUs\u00a0 and their I\/O modules.\u00a0 This voltage level is used for input modules and deliver 24VDC\u00a0 from output … Continue reading “Poorman” PLC I\/O board<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"_links":{"self":[{"href":"http:\/\/taptronics.com\/taptronics\/wp-json\/wp\/v2\/posts\/81"}],"collection":[{"href":"http:\/\/taptronics.com\/taptronics\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/taptronics.com\/taptronics\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/taptronics.com\/taptronics\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/taptronics.com\/taptronics\/wp-json\/wp\/v2\/comments?post=81"}],"version-history":[{"count":10,"href":"http:\/\/taptronics.com\/taptronics\/wp-json\/wp\/v2\/posts\/81\/revisions"}],"predecessor-version":[{"id":154,"href":"http:\/\/taptronics.com\/taptronics\/wp-json\/wp\/v2\/posts\/81\/revisions\/154"}],"wp:attachment":[{"href":"http:\/\/taptronics.com\/taptronics\/wp-json\/wp\/v2\/media?parent=81"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/taptronics.com\/taptronics\/wp-json\/wp\/v2\/categories?post=81"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/taptronics.com\/taptronics\/wp-json\/wp\/v2\/tags?post=81"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}