倍加福安全栅的有源信号和无源信号

倍加福安全栅具有有源信号和无源信号的概念，一般情况下，有源和无源是对AI (4-20mA)来说的。如果现场仪表需要卡件向它提供24V电源，那么此仪表的信号可以说是无源信号。如果现场仪表其他地方已经向它提供了24V电源，不需要卡件提供，此现场仪表的信号也可以说就是有源信号。一般情况下，需要卡件为变送器提供电源的为无源信号；不需要卡件为变送器提供电源，即变送器已单独供电的为有源信号。24V电源和信号叠加的为无源信号；电源和信号不叠加的为有源信号。

     当倍加福安全栅是两线制仪表并没有接电源的线时，就说明它们没有单独的工作电源，电源需要外部引入。两线制既要传输电源又要传输信号。采集模块不能提供24V电源，只有把电源串入信号回路里面。三线制仪表，有电源正端线、信号正端线，而电源的负端及信号的负端共用一根线，共三根线。它们输出信号称为有源信号。http://www.amypf.com/027-87263542手机：18372021864LED">ABSolute;top:0;border:0;width:undefinedpx;height:undefinedpx" SANdbox="allow-forms allow-popUPS allow-popups-to-escape-sandbox allow-same-origin allow-scripts allow-top-navigation-by-user-activation" frameborder="0" marginwidth="0" marginheight="0" vspace="0" hspace="0" allowtransparency="true" scrolling="no" src="https://googleads.g.doubleclick.net/pagead/ads?client=ca-pub-6745515041074118&ouTPUt=html&adk=1812271804&adf=3279755396&plat=3%3A32%2C4%3A32%2C8%3A134217728%2C9%3A134250504%2C16%3A8388608%2C17%3A32%2C24%3A32%2C25%3A32%2C30%3A1048576%2C32%3A32&format=0x0&url=https%3A%2F%2Fwww.bizrobot.com%2Fcompany_bloginfo.php%3Fact%3D1&ea=0&flash=29.0.0&pra=5&wgl=1&dt=1646364332418&bpp=6&bdt=226&idt=84&shv=r20220302&mjsv=m202202280101&ptt=9&saldr=aa&cookie=ID%3D2c186cce80d69fb1-221c8408a0ce006c%3AT%3D1636508022%3ART%3D1636508022%3AS%3DALNI_Mbu0HZjDtEO7dny0NgdC9Kvxw3uwg&nras=1&correlator=2791709892942&frm=23&ife=1&pv=1&ga_vid=1853962485.1646364333&ga_sid=1646364333&ga_hid=1367246485&ga_fc=0&nhd=1&u_tz=480&u_his=8&u_h=1080&u_w=1920&u_ah=1030&u_aw=1920&u_cd=24&u_sd=1&DMC=4&adx=-12245933&ady=-12245933&biw=1132&bih=945&isw=730&ish=360&ifk=2699508910&scr_x=0&scr_y=0&eid=42531398%2C44750773%2C31065368&oid=2&pvsid=3053880054375541&pem=217&tmod=586497464&uas=0&nvt=1&ref=https%3A%2F%2Fwww.bizrobot.com%2Fcompany_bloginfo.php%3Fact%3D1&eae=2&fc=1920&brdim=609%2C0%2C609%2C0%2C1920%2C0%2C1180%2C1082%2C730%2C360&vis=1&rsz=%7C%7Cs%7C&abl=NS&fu=32772&bc=31&ifi=1&uci=1.eksilrzh9o1z&fsb=1&dtd=93" data-google-container-id="1.eksilrzh9o1z" data-load-complete="true">