{"id":17692,"date":"2017-03-08T10:15:21","date_gmt":"2017-03-08T16:15:21","guid":{"rendered":"http:\/\/www.multitech.net\/developer\/?page_id=17692"},"modified":"2017-06-07T13:46:05","modified_gmt":"2017-06-07T18:46:05","slug":"mtac-gpio-electrical-requirements","status":"publish","type":"page","link":"https:\/\/www.multitech.net\/developer\/products\/multiconnect-conduit-platform\/accessory-cards\/mtac-gpio\/mtac-gpio-electrical-requirements\/","title":{"rendered":"MTAC-GPIO Electrical Requirements"},"content":{"rendered":"<h4>External Inputs 1-4:<\/h4>\n<p>These signals are optically isolated from the rest of the system. The External Input Ground pin is also isolated from the rest of the main board.\u00a0Current draw of the input is approximately 500 uA for a 3VDC input,\u00a0increasing to 8.5 mA for a 30 VDC input. In order to see a &#8220;1&#8221; on a\u00a0External Input\u00a0pin, you need to supply a voltage between 3VDC and 30VDC to turn on the optoisolator input.<\/p>\n<p>Equivalent Circuit:<\/p>\n<p><a href=\"https:\/\/www.multitech.net\/developer\/wp-content\/uploads\/2017\/03\/ext_input_pic1.png\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-medium wp-image-17709\" alt=\"ext_input_pic1\" src=\"https:\/\/www.multitech.net\/developer\/wp-content\/uploads\/2017\/03\/ext_input_pic1-300x127.png\" width=\"300\" height=\"127\" srcset=\"https:\/\/www.multitech.net\/developer\/wp-content\/uploads\/2017\/03\/ext_input_pic1-300x127.png 300w, https:\/\/www.multitech.net\/developer\/wp-content\/uploads\/2017\/03\/ext_input_pic1.png 625w\" sizes=\"auto, (max-width: 300px) 100vw, 300px\" \/><\/a><\/p>\n<h5>External Outputs 1-4:<\/h5>\n<p>These signals are open collector with maximum working voltage Of 55VDC and maximum current draw of 300mA. <strong>These signals share a common ground\u00a0with the system, and cannot be used on isolated signals.<\/strong>\u00a0\u00a0If an output is used as an\u00a0&#8220;digital&#8221; signal, an external pull up resistor is required for proper operation. If an output is being used to drive an inductive load, such as a relay,\u00a0a clipping diode is recommended to protect the output circuitry from inductive spikes.<\/p>\n<p>Equivalent circuit:<\/p>\n<p><a href=\"https:\/\/www.multitech.net\/developer\/wp-content\/uploads\/2011\/01\/DOUT-Equivalent-Circuit.png\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone  wp-image-1710\" alt=\"DOUT Equivalent Circuit\" src=\"https:\/\/www.multitech.net\/developer\/wp-content\/uploads\/2011\/01\/DOUT-Equivalent-Circuit.png\" width=\"327\" height=\"200\" \/><\/a><\/p>\n<h5>Analog Inputs 1-3:<\/h5>\n<p>These signals are analog inputs fed through an operation amplifier buffer to a 12 bit Analog to Digital converter (ADC). The ADC on the GPIO card is a ADS7950S. The +Vref is being generated by a LMV431A precision source\u00a0set to 2.48V. The ADC has a =Vref * 2 setting for 4.960V full scale. This is hardcoded by the firmware.\u00a0The inputs are multiplex, so only one voltage is converted per system call. The input is scaled to accept a 0-5VDC input. These signals share a common ground with the main board, and cannot be used on isolated signals. Input max is recommended to be no greater than 5.2V.<\/p>\n<p>Equivalent circuit:<br \/>\n<a href=\"https:\/\/www.multitech.net\/developer\/wp-content\/uploads\/2011\/01\/Analog-Inputs-Equivalent-Circuit.png\"><img decoding=\"async\" title=\"Analog Inputs Equivalent Circuit\" alt=\"\" src=\"https:\/\/www.multitech.net\/developer\/wp-content\/uploads\/2011\/01\/Analog-Inputs-Equivalent-Circuit.png\" width=\"250\" \/><\/a><\/p>\n","protected":false},"excerpt":{"rendered":"<p>External Inputs 1-4: These signals are optically isolated from the rest of the system. The External Input Ground pin is also isolated from the rest of the main board.\u00a0Current draw of the input is approximately 500 uA for a 3VDC input,\u00a0increasing to 8.5 mA for a 30 VDC input. In order to see a &#8220;1&#8221; [&hellip;]<\/p>\n","protected":false},"author":2488,"featured_media":0,"parent":6729,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"_bbp_topic_count":0,"_bbp_reply_count":0,"_bbp_total_topic_count":0,"_bbp_total_reply_count":0,"_bbp_voice_count":0,"_bbp_anonymous_reply_count":0,"_bbp_topic_count_hidden":0,"_bbp_reply_count_hidden":0,"_bbp_forum_subforum_count":0,"footnotes":""},"class_list":["post-17692","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/www.multitech.net\/developer\/wp-json\/wp\/v2\/pages\/17692","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.multitech.net\/developer\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/www.multitech.net\/developer\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/www.multitech.net\/developer\/wp-json\/wp\/v2\/users\/2488"}],"replies":[{"embeddable":true,"href":"https:\/\/www.multitech.net\/developer\/wp-json\/wp\/v2\/comments?post=17692"}],"version-history":[{"count":13,"href":"https:\/\/www.multitech.net\/developer\/wp-json\/wp\/v2\/pages\/17692\/revisions"}],"predecessor-version":[{"id":17712,"href":"https:\/\/www.multitech.net\/developer\/wp-json\/wp\/v2\/pages\/17692\/revisions\/17712"}],"up":[{"embeddable":true,"href":"https:\/\/www.multitech.net\/developer\/wp-json\/wp\/v2\/pages\/6729"}],"wp:attachment":[{"href":"https:\/\/www.multitech.net\/developer\/wp-json\/wp\/v2\/media?parent=17692"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}