{"id":1150,"date":"2026-08-20T12:00:00","date_gmt":"2026-08-20T04:00:00","guid":{"rendered":"https:\/\/lemaele.com\/blog\/24v-push-button-switch-plc-interface-guide\/"},"modified":"2026-08-20T18:48:51","modified_gmt":"2026-08-20T10:48:51","slug":"24v-push-button-switch-plc-interface-guide","status":"publish","type":"post","link":"https:\/\/lemaele.com\/it\/blog\/24v-push-button-switch-plc-interface-guide\/","title":{"rendered":"24V Push Button Switch: PLC Input Interface Notes for OEM Panels"},"content":{"rendered":"<div class=\"b2b-article\">\n<p style=\"margin:0 0 16px;line-height:1.7\">A <strong>24V push button switch<\/strong> becomes a PLC digital input when its dry contact closes a low-current 24V DC loop that matches the input module\u2019s sinking or sourcing common. This article walks through that interface logic, the difference between passive buttons and PNP\/NPN sensors, how illuminated operators split contact and lamp paths, and the commissioning checks OEM panels need before ladder logic is trusted.<\/p>\n<figure style=\"margin:26px 0;text-align:center\"><img decoding=\"async\" style=\"max-width:640px;width:100%;height:auto;display:block;margin:0 auto;border-radius:8px\" alt=\"24V push button on an OEM control panel for PLC input interface\" src=\"https:\/\/lemaele.com\/wp-content\/uploads\/2026\/08\/24v-plc-pb-featured.webp\" title=\"\"><\/figure>\n<p style=\"margin:0 0 16px;line-height:1.7\">The panel scene below mirrors the operator-to-input topic of this guide.<\/p>\n<nav class=\"b2b-toc\" style=\"background:#f5f8fa;padding:16px 20px;border-radius:8px;margin:0 0 24px\">\n<h2 id=\"contents\" style=\"margin:42px 0 14px;scroll-margin-top:96px\">Contenuti<\/h2>\n<ul style=\"margin:0 0 18px 1.2em;line-height:1.7\">\n<li style=\"margin:0 0 8px\"><a style=\"color:#f27c00;text-decoration:underline\" href=\"#what-a-plc-push-button-interface-actually-does\">What a PLC Push-Button Interface Actually Does<\/a><\/li>\n<li style=\"margin:0 0 8px\"><a style=\"color:#f27c00;text-decoration:underline\" href=\"#sinking-vs-sourcing-wiring-for-dry-contact-buttons\">Sinking vs Sourcing Wiring for Dry-Contact Buttons<\/a><\/li>\n<li style=\"margin:0 0 8px\"><a style=\"color:#f27c00;text-decoration:underline\" href=\"#why-push-buttons-are-not-wired-like-pnp-npn-sensors\">Why Push Buttons Are Not Wired Like PNP\/NPN Sensors<\/a><\/li>\n<li style=\"margin:0 0 8px\"><a style=\"color:#f27c00;text-decoration:underline\" href=\"#illuminated-operators-contact-path-vs-lamp-path\">Illuminated Operators: Contact Path vs Lamp Path<\/a><\/li>\n<li style=\"margin:0 0 8px\"><a style=\"color:#f27c00;text-decoration:underline\" href=\"#commissioning-checks-before-you-trust-the-ladder\">Commissioning Checks Before You Trust the Ladder<\/a><\/li>\n<li style=\"margin:0 0 8px\"><a style=\"color:#f27c00;text-decoration:underline\" href=\"#oem-notes-when-specifying-a-panel-push-button\">OEM Notes When Specifying a Panel Push Button<\/a><\/li>\n<li style=\"margin:0 0 8px\"><a style=\"color:#f27c00;text-decoration:underline\" href=\"#choose-pbs-series-push-button-switch-for-panel-interfaces\">Choose PBS Series Push Button Switch for Panel Interfaces<\/a><\/li>\n<li style=\"margin:0 0 8px\"><a style=\"color:#f27c00;text-decoration:underline\" href=\"#faq\">FAQ<\/a><\/li>\n<\/ul>\n<\/nav>\n<p style=\"margin:0 0 16px;line-height:1.7\">Use this list to jump through the interface notes.<\/p>\n<ul style=\"margin:0 0 18px 1.2em;line-height:1.7\">\n<li style=\"margin:0 0 8px\">What a PLC Push-Button Interface Actually Does<\/li>\n<li style=\"margin:0 0 8px\">Sinking vs Sourcing Wiring for Dry-Contact Buttons<\/li>\n<li style=\"margin:0 0 8px\">Why Push Buttons Are Not Wired Like PNP\/NPN Sensors<\/li>\n<li style=\"margin:0 0 8px\">Illuminated Operators: Contact Path vs Lamp Path<\/li>\n<li style=\"margin:0 0 8px\">Commissioning Checks Before You Trust the Ladder<\/li>\n<li style=\"margin:0 0 8px\">OEM Notes When Specifying a Panel Push Button<\/li>\n<li style=\"margin:0 0 8px\">Choose PBS Series Push Button Switch for Panel Interfaces<\/li>\n<li style=\"margin:0 0 8px\">FAQ<\/li>\n<li style=\"margin:0 0 8px\">Riferimenti<\/li>\n<\/ul>\n<h2 style=\"margin:42px 0 14px;scroll-margin-top:96px\" id=\"what-a-plc-push-button-interface-actually-does\">What a PLC Push-Button Interface Actually Does<\/h2>\n<p style=\"margin:0 0 16px;line-height:1.7\">It closes a low-current 24V DC sensing loop into a discrete PLC input\u2014nothing more exotic than that.<\/p>\n<p style=\"margin:0 0 16px;line-height:1.7\">A digital input module detects whether a field device is open or closed by watching voltage or current at the terminal. In a typical 24V control circuit, the push button, the input point, and the power supply form one continuous loop. When the operator presses the button, the contact finishes that loop and the module reports an ON state to the CPU.<\/p>\n<p style=\"margin:0 0 16px;line-height:1.7\">That current is small. Educational PLC material commonly describes digital input current as usually under 10 mA, but the exact ON\/OFF thresholds still come from the module datasheet for your rack. Treat the button as a signal device for the PLC, not as a substitute for a power contactor.<\/p>\n<p style=\"margin:0 0 16px;line-height:1.7\">Many modules use an opto-isolated input front end, so the field wiring stays galvanically separated from the logic side. The practical takeaway for panel designers is simple: land the contact so the sensing LED inside the module can light when the operator presses the button, then confirm the same transition in the programming software.<\/p>\n<h2 style=\"margin:42px 0 14px;scroll-margin-top:96px\" id=\"sinking-vs-sourcing-wiring-for-dry-contact-buttons\">Sinking vs Sourcing Wiring for Dry-Contact Buttons<\/h2>\n<p style=\"margin:0 0 16px;line-height:1.7\">Match the button polarity to the module common, then keep every point on that common bank consistent.<\/p>\n<p style=\"margin:0 0 16px;line-height:1.7\">Sinking and sourcing describe the direction of conventional current between the field device and the PLC input. The terms apply to DC circuits. They do not describe AC input modules the same way.<\/p>\n<div class=\"b2b-table-scroll\" role=\"region\" aria-label=\"Tabella di dati scorrevole\" tabindex=\"0\" style=\"width:100%;max-width:100%;overflow-x:auto;-webkit-overflow-scrolling:touch;margin:0 0 18px\">\n<table style=\"width:100%;border-collapse:collapse\">\n<thead>\n<tr>\n<th style=\"border:1px solid #d9e1e8;padding:9px 12px;background:#f5f8fa;text-align:left\">Module mode<\/th>\n<th style=\"border:1px solid #d9e1e8;padding:9px 12px;background:#f5f8fa;text-align:left\">Typical COM connection<\/th>\n<th style=\"border:1px solid #d9e1e8;padding:9px 12px;background:#f5f8fa;text-align:left\">Dry-contact push button wiring<\/th>\n<th style=\"border:1px solid #d9e1e8;padding:9px 12px;background:#f5f8fa;text-align:left\">What \u201cON\u201d usually means at the terminal<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td style=\"border:1px solid #d9e1e8;padding:9px 12px\">Sinking input<\/td>\n<td style=\"border:1px solid #d9e1e8;padding:9px 12px\">COM to 0 V (DC\u2212)<\/td>\n<td style=\"border:1px solid #d9e1e8;padding:9px 12px\">Feed +24 V through the NO contact into the input point<\/td>\n<td style=\"border:1px solid #d9e1e8;padding:9px 12px\">Input sees a positive voltage when pressed<\/td>\n<\/tr>\n<tr>\n<td style=\"border:1px solid #d9e1e8;padding:9px 12px\">Sourcing input<\/td>\n<td style=\"border:1px solid #d9e1e8;padding:9px 12px\">COM to +24 V (DC+)<\/td>\n<td style=\"border:1px solid #d9e1e8;padding:9px 12px\">Feed 0 V through the NO contact into the input point<\/td>\n<td style=\"border:1px solid #d9e1e8;padding:9px 12px\">Input is pulled toward 0 V when pressed<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<p style=\"margin:0 0 16px;line-height:1.7\">Shared commons matter. If eight inputs share one Common terminal (COM), wire the whole bank the same way.<\/p>\n<p style=\"margin:0 0 16px;line-height:1.7\">Mixed polarities on one common create a frequent commissioning trap. Those banks then produce inputs that never turn on, or that look permanently true.<\/p>\n<figure style=\"margin:26px 0;text-align:center\"><img decoding=\"async\" style=\"max-width:640px;width:100%;height:auto;display:block;margin:0 auto;border-radius:8px\" alt=\"PBS series push button assembly used as a dry-contact PLC operator\" src=\"https:\/\/lemaele.com\/wp-content\/uploads\/2026\/08\/24v-plc-pb-body-dry-contact.webp\" title=\"\"><\/figure>\n<p style=\"margin:0 0 16px;line-height:1.7\">The contact block under the operator is what lands on the digital input terminal strip.<\/p>\n<blockquote>\n<p style=\"margin:0 0 16px;line-height:1.7\"><strong>Importante:<\/strong> Match the push-button circuit voltage to the digital input rating \u2014 source: <a style=\"color:#f27c00;text-decoration:underline\" href=\"https:\/\/cdn.automationdirect.com\/static\/specs\/sinksource.pdf\" target=\"_blank\" rel=\"noopener\">AutomationDirect sinking and sourcing concepts<\/a>. Applying a higher voltage class than the module allows can destroy the input front end.<\/p>\n<\/blockquote>\n<p style=\"margin:0 0 16px;line-height:1.7\">Keep AC supplies off DC sink\/source input points.<\/p>\n<h2 style=\"margin:42px 0 14px;scroll-margin-top:96px\" id=\"why-push-buttons-are-not-wired-like-pnp-npn-sensors\">Why Push Buttons Are Not Wired Like PNP\/NPN Sensors<\/h2>\n<p style=\"margin:0 0 16px;line-height:1.7\">Buttons are passive dry contacts; three-wire sensors are polarity-fixed devices.<\/p>\n<p style=\"margin:0 0 16px;line-height:1.7\">A mechanical push button does not contain a PNP or NPN output transistor. Current can pass either way through the contact, so the same operator can support a sinking or a sourcing input bank once you choose which side of the supply the contact switches.<\/p>\n<p style=\"margin:0 0 16px;line-height:1.7\">Active sensors are different. A PNP \/ NPN sensor output is polarity-fixed, unlike a dry-contact button.<\/p>\n<p style=\"margin:0 0 16px;line-height:1.7\">A PNP (sourcing) sensor must pair with a sinking input. An NPN (sinking) sensor must pair with a sourcing input.<\/p>\n<p style=\"margin:0 0 16px;line-height:1.7\">Installers who force push buttons to \u201cfollow the NPN sensor group\u201d create unnecessary RFQ confusion. Community technicians often ask whether a controller \u201cneeds PNP or NPN,\u201d and for sensors the useful answer is pairing.<\/p>\n<p style=\"margin:0 0 16px;line-height:1.7\">On a mixed panel, keep sensor polarity rules for the sensor terminals, and treat start\/stop operators as unbiased switches that simply complete the bank\u2019s chosen polarity.<\/p>\n<blockquote>\n<p style=\"margin:0 0 16px;line-height:1.7\"><strong>Dall'esperienza sul campo:<\/strong> Forum installers often ask whether push buttons must be wired like NPN sensors on the same PLC \u2014 source: community wiring threads summarized via <a style=\"color:#f27c00;text-decoration:underline\" href=\"https:\/\/forum.arduino.cc\/t\/pnp-or-npn-dumb-question\/1181748\" target=\"_blank\" rel=\"noopener\">Arduino Forum PNP\/NPN discussion<\/a>. Experienced replies emphasize that a regular contact switch can sit on either the sinking or sourcing side, while solid-state sensors cannot.<\/p>\n<\/blockquote>\n<h2 style=\"margin:42px 0 14px;scroll-margin-top:96px\" id=\"illuminated-operators-contact-path-vs-lamp-path\">Illuminated Operators: Contact Path vs Lamp Path<\/h2>\n<p style=\"margin:0 0 16px;line-height:1.7\">Use the contact for the digital input; power the LED on its own circuit.<\/p>\n<p style=\"margin:0 0 16px;line-height:1.7\">An illuminated \/ LED push button adds a lamp path beside the switching contact.<\/p>\n<p style=\"margin:0 0 16px;line-height:1.7\">In a documented Click PLUS lab build, the normally open contact feeds the PLC input while the lamp is driven from a PLC output return path. That separation keeps sensing current independent from lamp current.<\/p>\n<p style=\"margin:0 0 16px;line-height:1.7\">When you specify an illuminated push button for 24V OEM work, document two circuits on the schematic: the dry-contact DI path and the lamp supply\/return path. Do not assume one pair of terminals does both jobs.<\/p>\n<figure style=\"margin:26px 0;text-align:center\"><img decoding=\"async\" style=\"max-width:640px;width:100%;height:auto;display:block;margin:0 auto;border-radius:8px\" alt=\"Illuminated-style PBS push button operator with microswitch contact block\" src=\"https:\/\/lemaele.com\/wp-content\/uploads\/2026\/08\/24v-plc-pb-body-illuminated.webp\" title=\"\"><\/figure>\n<p style=\"margin:0 0 16px;line-height:1.7\">Keep the lamp circuit notes next to the contact circuit on the drawing.<\/p>\n<p style=\"margin:0 0 16px;line-height:1.7\">On the LEMA <a style=\"color:#f27c00;text-decoration:underline\" href=\"https:\/\/lemaele.com\/it\/prodotto\/pbs-series-push-button-switch\/\">Interruttore a pulsante della serie PBS<\/a> page, LED light is an ordering option (<code>L: With LED<\/code> or without LED). That option matters for panel graphics and night visibility, but it does not replace the sink\/source decision for the contact that lands on the PLC input.<\/p>\n<h2 style=\"margin:42px 0 14px;scroll-margin-top:96px\" id=\"commissioning-checks-before-you-trust-the-ladder\">Commissioning Checks Before You Trust the Ladder<\/h2>\n<p style=\"margin:0 0 16px;line-height:1.7\">Prove voltage, COM mode, and software status before blaming logic.<\/p>\n<ol style=\"margin:0 0 18px 1.2em;line-height:1.7\">\n<li style=\"margin:0 0 8px\">Read the input module label for voltage class and sink\/source (or configurable) mode.<\/li>\n<li style=\"margin:0 0 8px\">Trace the COM terminal to +24 V or 0 V and write that mode on the terminal strip.<\/li>\n<li style=\"margin:0 0 8px\">Land one side of the NO contact to the supply pole required by that mode; land the other side to the assigned input.<\/li>\n<li style=\"margin:0 0 8px\">Use ferrules on stranded control wire at screw terminals when the hardware allows\u2014stranded whiskers are a frequent short risk on dense PLC rows.<\/li>\n<li style=\"margin:0 0 8px\">Press the button and confirm both the module status indicator and the online input bit.<\/li>\n<li style=\"margin:0 0 8px\">Measure voltage at the terminal if the LED and the software disagree. LED alone can mislead when leakage or floating inputs are present.<\/li>\n<\/ol>\n<figure style=\"margin:26px 0;text-align:center\"><img decoding=\"async\" style=\"max-width:640px;width:100%;height:auto;display:block;margin:0 auto;border-radius:8px\" alt=\"PBS push button rear terminals for PLC input landing\" src=\"https:\/\/lemaele.com\/wp-content\/uploads\/2026\/08\/24v-plc-pb-body-terminals.webp\" title=\"\"><\/figure>\n<p style=\"margin:0 0 16px;line-height:1.7\">Terminal access is where ferrules and polarity checks pay off during commissioning.<\/p>\n<p style=\"margin:0 0 16px;line-height:1.7\">If the input stays ON regardless of the button, re-check COM polarity and look for a welded or mis-landed contact that permanently completes the loop. If the input never turns ON, confirm the bank mode, the supply polarity through the contact, and that you did not place an AC circuit on a DC-only input point.<\/p>\n<h2 style=\"margin:42px 0 14px;scroll-margin-top:96px\" id=\"oem-notes-when-specifying-a-panel-push-button\">OEM Notes When Specifying a Panel Push Button<\/h2>\n<p style=\"margin:0 0 16px;line-height:1.7\">Document voltage, module mode, contact form, LED need, and colour\u2014without inventing unpublished ratings.<\/p>\n<div class=\"b2b-table-scroll\" role=\"region\" aria-label=\"Tabella di dati scorrevole\" tabindex=\"0\" style=\"width:100%;max-width:100%;overflow-x:auto;-webkit-overflow-scrolling:touch;margin:0 0 18px\">\n<table style=\"width:100%;border-collapse:collapse\">\n<thead>\n<tr>\n<th style=\"border:1px solid #d9e1e8;padding:9px 12px;background:#f5f8fa;text-align:left\">Spec item<\/th>\n<th style=\"border:1px solid #d9e1e8;padding:9px 12px;background:#f5f8fa;text-align:left\">What to write on the OEM drawing \/ RFQ note<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td style=\"border:1px solid #d9e1e8;padding:9px 12px\">Tensione di controllo<\/td>\n<td style=\"border:1px solid #d9e1e8;padding:9px 12px\">24V DC digital input circuit (match module rating)<\/td>\n<\/tr>\n<tr>\n<td style=\"border:1px solid #d9e1e8;padding:9px 12px\">Input mode<\/td>\n<td style=\"border:1px solid #d9e1e8;padding:9px 12px\">Sinking or sourcing; COM polarity for the bank<\/td>\n<\/tr>\n<tr>\n<td style=\"border:1px solid #d9e1e8;padding:9px 12px\">Contact role<\/td>\n<td style=\"border:1px solid #d9e1e8;padding:9px 12px\">Dry-contact NO (and NC if used) as PLC DI, not motor load switching<\/td>\n<\/tr>\n<tr>\n<td style=\"border:1px solid #d9e1e8;padding:9px 12px\">Illumination<\/td>\n<td style=\"border:1px solid #d9e1e8;padding:9px 12px\">LED required or not; separate lamp circuit noted<\/td>\n<\/tr>\n<tr>\n<td style=\"border:1px solid #d9e1e8;padding:9px 12px\">Operator colour<\/td>\n<td style=\"border:1px solid #d9e1e8;padding:9px 12px\">Colour code for the panel legend<\/td>\n<\/tr>\n<tr>\n<td style=\"border:1px solid #d9e1e8;padding:9px 12px\">Evidence boundary<\/td>\n<td style=\"border:1px solid #d9e1e8;padding:9px 12px\">Request datasheet values for ratings, IP, or cutout before claiming them<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<p style=\"margin:0 0 16px;line-height:1.7\">Buyers sometimes ask for \u201cPLC-compatible push buttons\u201d as if compatibility were a single SKU flag. Compatibility is a wiring and rating match: the contact must handle the module\u2019s sensing circuit, and the mechanical operator must fit the panel design. If a datasheet value is missing from the public product page, leave it blank on the claim list and ask for the drawing package instead of guessing.<\/p>\n<p style=\"margin:0 0 16px;line-height:1.7\">Colour coding still helps operators. The PBS ordering table lists R, Y, B, G, P, and W. Use those codes to keep start, stop, and mode buttons visually consistent across machines built for global customers.<\/p>\n<h2 style=\"margin:42px 0 14px;scroll-margin-top:96px\" id=\"choose-pbs-series-push-button-switch-for-panel-interfaces\">Choose PBS Series Push Button Switch for Panel Interfaces<\/h2>\n<p style=\"margin:0 0 16px;line-height:1.7\">Consider PBS when you need colour and optional LED operators for automation panels that feed 24V PLC inputs.<\/p>\n<p style=\"margin:0 0 16px;line-height:1.7\">After the interface rules above are set, the remaining product decision is which operator family covers the panel\u2019s colours and illumination needs. The <a style=\"color:#f27c00;text-decoration:underline\" href=\"https:\/\/lemaele.com\/it\/prodotto\/pbs-series-push-button-switch\/\">Interruttore a pulsante della serie PBS<\/a> is a snap-action push button series aimed at industrial and commercial equipment, including automation panels. The public page documents LED ordering, the six colour codes, and notes that some models can be equipped with KW7 series micro switches.<\/p>\n<figure style=\"margin:26px 0;text-align:center\"><img decoding=\"async\" style=\"max-width:640px;width:100%;height:auto;display:block;margin:0 auto;border-radius:8px\" alt=\"PBS Series Push Button Switch product photo for OEM panel recommendation\" src=\"https:\/\/lemaele.com\/wp-content\/uploads\/2026\/05\/PBS-001.webp\" title=\"\"><\/figure>\n<p style=\"margin:0 0 16px;line-height:1.7\">Review the colour and LED ordering fields before freezing the panel legend.<\/p>\n<p style=\"margin:0 0 16px;line-height:1.7\">Choose another path when the project requires verified IP performance, a certified emergency-stop function, or published electrical ratings that are not shown on the current product page. In those cases, keep the interface notes from this article and request model-level evidence before freezing the BOM.<\/p>\n<h2 style=\"margin:42px 0 14px;scroll-margin-top:96px\" id=\"faq\">FAQ<\/h2>\n<h3 style=\"margin:28px 0 12px\">How do you wire a push button to a PLC input?<\/h3>\n<p style=\"margin:0 0 16px;line-height:1.7\">Complete a DC loop through the button contact and the input point.<\/p>\n<p style=\"margin:0 0 16px;line-height:1.7\">For a sinking bank with COM at 0 V, feed +24 V through the NO contact into the input. For a sourcing bank with COM at +24 V, feed 0 V through the contact into the input. Then prove the bit in software.<\/p>\n<h3 style=\"margin:28px 0 12px\">What is the difference between sinking and sourcing PLC inputs?<\/h3>\n<p style=\"margin:0 0 16px;line-height:1.7\">Sinking inputs accept current into the module toward the common return. Sourcing inputs supply current out of the module toward the field device. The push button only has to switch the correct supply pole for the mode you chose.<\/p>\n<h3 style=\"margin:28px 0 12px\">Are push buttons PNP or NPN devices?<\/h3>\n<p style=\"margin:0 0 16px;line-height:1.7\">No. Mechanical push buttons are dry contacts without a fixed transistor output type.<\/p>\n<p style=\"margin:0 0 16px;line-height:1.7\">PNP and NPN labels belong to active sensors. Wire the button to match the PLC input mode instead of forcing a sensor label onto it.<\/p>\n<h3 style=\"margin:28px 0 12px\">Why does a PLC input stay ON after I wire the push button?<\/h3>\n<p style=\"margin:0 0 16px;line-height:1.7\">Common causes include reversed sink\/source assumptions on the COM terminal, a contact landed so the loop is always complete, or a module bank sharing a common that was polarized for a different field device style. Re-trace COM, measure the terminal, and compare the online bit.<\/p>\n<h3 style=\"margin:28px 0 12px\">Does an illuminated push button need a separate path for the LED?<\/h3>\n<p style=\"margin:0 0 16px;line-height:1.7\">Usually yes. Keep the dry contact on the digital input circuit and power the lamp or LED on its own supply\/return\u2014often from a PLC output in lab examples. On PBS, LED is an ordering option and should be treated as a separate functional choice from the contact wiring.<\/p>\n<h3 style=\"margin:28px 0 12px\">Can I mix proximity sensors and push buttons on one input bank?<\/h3>\n<p style=\"margin:0 0 16px;line-height:1.7\">Yes, if every device on that shared common is wired for the same sink or source mode. Sensors must match the module type; push buttons can be polarized to follow the bank. Do not mix opposite polarities on one COM.<\/p>\n<h3 style=\"margin:28px 0 12px\">What should OEM buyers confirm before ordering a panel push button for PLC use?<\/h3>\n<p style=\"margin:0 0 16px;line-height:1.7\">Confirm 24V DC input rating match, sink\/source mode, NO\/NC contact needs, whether LED illumination is required, colour codes for the legend, and any datasheet items not published on the marketing page. Then select a family such as PBS only after those notes are written.<\/p>\n<h2 style=\"margin:42px 0 14px;scroll-margin-top:96px\" id=\"references\">Riferimenti<\/h2>\n<ol style=\"margin:0 0 18px 1.2em;line-height:1.7\">\n<li style=\"margin:0 0 8px\"><a style=\"color:#f27c00;text-decoration:underline\" href=\"https:\/\/cdn.automationdirect.com\/static\/specs\/sinksource.pdf\" target=\"_blank\" rel=\"noopener\">Sinking and Sourcing Concepts (AutomationDirect technical appendix)<\/a><\/li>\n<li style=\"margin:0 0 8px\"><a style=\"color:#f27c00;text-decoration:underline\" href=\"https:\/\/www.realpars.com\/blog\/sinking-and-sourcing\" target=\"_blank\" rel=\"noopener\">Sinking and Sourcing PLC Inputs Explained (RealPars)<\/a><\/li>\n<li style=\"margin:0 0 8px\"><a style=\"color:#f27c00;text-decoration:underline\" href=\"https:\/\/accautomation.ca\/how-to-connect-pushbutton-switch-to-plc\/\" target=\"_blank\" rel=\"noopener\">How to Connect a Pushbutton Switch to a PLC (ACC Automation)<\/a><\/li>\n<li style=\"margin:0 0 8px\"><a style=\"color:#f27c00;text-decoration:underline\" href=\"https:\/\/forum.arduino.cc\/t\/pnp-or-npn-dumb-question\/1181748\" target=\"_blank\" rel=\"noopener\">PNP or NPN \u2014 Dumb Question (Arduino Forum community thread)<\/a><\/li>\n<\/ol>\n<\/div>","protected":false},"excerpt":{"rendered":"<p>Progettare un pulsante di comando a 24 V come ingresso PLC: logica sinking e sourcing, cablaggio con contatto pulito, circuiti LED di segnalazione e verifiche di messa in servizio per quadri OEM.<\/p>","protected":false},"author":6,"featured_media":1159,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"class_list":["post-1150","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-blog"],"_links":{"self":[{"href":"https:\/\/lemaele.com\/it\/wp-json\/wp\/v2\/posts\/1150","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/lemaele.com\/it\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/lemaele.com\/it\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/lemaele.com\/it\/wp-json\/wp\/v2\/users\/6"}],"replies":[{"embeddable":true,"href":"https:\/\/lemaele.com\/it\/wp-json\/wp\/v2\/comments?post=1150"}],"version-history":[{"count":1,"href":"https:\/\/lemaele.com\/it\/wp-json\/wp\/v2\/posts\/1150\/revisions"}],"predecessor-version":[{"id":1163,"href":"https:\/\/lemaele.com\/it\/wp-json\/wp\/v2\/posts\/1150\/revisions\/1163"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/lemaele.com\/it\/wp-json\/wp\/v2\/media\/1159"}],"wp:attachment":[{"href":"https:\/\/lemaele.com\/it\/wp-json\/wp\/v2\/media?parent=1150"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/lemaele.com\/it\/wp-json\/wp\/v2\/categories?post=1150"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/lemaele.com\/it\/wp-json\/wp\/v2\/tags?post=1150"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}