{"id":25997,"date":"2022-04-03T19:21:29","date_gmt":"2022-04-03T12:21:29","guid":{"rendered":"https:\/\/tom.ji42.com\/?p=25997"},"modified":"2022-05-24T16:14:04","modified_gmt":"2022-05-24T09:14:04","slug":"%e0%b8%81%e0%b8%b2%e0%b8%a3%e0%b8%95%e0%b9%88%e0%b8%ad-rs232-%e0%b9%81%e0%b8%9a%e0%b8%9a-crossover-or-null-modem-%e0%b9%80%e0%b8%8a%e0%b8%b7%e0%b9%88%e0%b8%ad%e0%b8%a1-optimod","status":"publish","type":"post","link":"https:\/\/tom.tomwork.net\/?p=25997","title":{"rendered":"\u0e01\u0e32\u0e23\u0e15\u0e48\u0e2d RS232 \u0e41\u0e1a\u0e1a Crossover or Null Modem \u0e40\u0e0a\u0e37\u0e48\u0e2d\u0e21 Optimod"},"content":{"rendered":"<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<p><b>\u0e01\u0e32\u0e23\u0e15\u0e48\u0e2d RS232 \u0e41\u0e1a\u0e1a Crossover or Null Modem \u0e40\u0e0a\u0e37\u0e48\u0e2d\u0e21 Optimod<\/b><\/p>\n<p><a href=\"https:\/\/tom.tomwork.net\/wp-content\/uploads\/2022\/04\/o12.jpg\"><img loading=\"lazy\" decoding=\"async\" onerror=\"this.src='https:\/\/tom.tomwork.net\/wp-content\/uploads\/2020\/11\/no-picture-available-icon-1.png'\" style=\"margin: 0px; display: inline; background-image: none;\" title=\"o1[2]\" src=\"https:\/\/tom.tomwork.net\/wp-content\/uploads\/2022\/04\/o12_thumb.jpg\" alt=\"o1[2]\" width=\"9\" height=\"9\" border=\"0\" \/><\/a><a href=\"https:\/\/tom.tomwork.net\/wp-content\/uploads\/2022\/04\/o2.jpg\"><br \/>\n<\/a><a href=\"https:\/\/tom.tomwork.net\/wp-content\/uploads\/2022\/04\/pic1514726183.jpg\"><img loading=\"lazy\" decoding=\"async\" onerror=\"this.src='https:\/\/tom.tomwork.net\/wp-content\/uploads\/2020\/11\/no-picture-available-icon-1.png'\" style=\"border: 0px currentcolor; display: inline; background-image: none;\" title=\"pic1514726183\" src=\"https:\/\/tom.tomwork.net\/wp-content\/uploads\/2022\/04\/pic1514726183_thumb.jpg\" alt=\"pic1514726183\" width=\"880\" height=\"659\" border=\"0\" \/><\/a><\/p>\n<p>\u0e40\u0e01\u0e47\u0e1a\u0e02\u0e49\u0e2d\u0e21\u0e39\u0e25\u0e44\u0e27\u0e49\u0e14\u0e39 \u0e01\u0e32\u0e23\u0e15\u0e48\u0e2d RS232 \u0e41\u0e1a\u0e1a Crossover or Null Modem\u00a0 \u0e43\u0e0a\u0e49\u0e23\u0e35\u0e42\u0e21\u0e17\u0e40\u0e0a\u0e37\u0e48\u0e2d\u0e21 Software \u0e01\u0e31\u0e1a Optimod 8400<\/p>\n<p><!--more--><\/p>\n<p><a href=\"https:\/\/tom.tomwork.net\/wp-content\/uploads\/2022\/04\/o15.jpg\"><img loading=\"lazy\" decoding=\"async\" onerror=\"this.src='https:\/\/tom.tomwork.net\/wp-content\/uploads\/2020\/11\/no-picture-available-icon-1.png'\" style=\"margin: 0px; display: inline; background-image: none;\" title=\"o1[5]\" src=\"https:\/\/tom.tomwork.net\/wp-content\/uploads\/2022\/04\/o15_thumb.jpg\" alt=\"o1[5]\" width=\"9\" height=\"9\" border=\"0\" \/><\/a><br \/>\n<a href=\"https:\/\/tom.tomwork.net\/wp-content\/uploads\/2022\/04\/pic1514726208.jpg\"><img loading=\"lazy\" decoding=\"async\" onerror=\"this.src='https:\/\/tom.tomwork.net\/wp-content\/uploads\/2020\/11\/no-picture-available-icon-1.png'\" style=\"border: 0px currentcolor; display: inline; background-image: none;\" title=\"pic1514726208\" src=\"https:\/\/tom.tomwork.net\/wp-content\/uploads\/2022\/04\/pic1514726208_thumb.jpg\" alt=\"pic1514726208\" width=\"586\" height=\"386\" border=\"0\" \/><\/a><\/p>\n<p><a href=\"https:\/\/tom.tomwork.net\/wp-content\/uploads\/2022\/04\/o18.jpg\"><img loading=\"lazy\" decoding=\"async\" onerror=\"this.src='https:\/\/tom.tomwork.net\/wp-content\/uploads\/2020\/11\/no-picture-available-icon-1.png'\" style=\"margin: 0px; display: inline; background-image: none;\" title=\"o1[8]\" src=\"https:\/\/tom.tomwork.net\/wp-content\/uploads\/2022\/04\/o18_thumb.jpg\" alt=\"o1[8]\" width=\"9\" height=\"9\" border=\"0\" \/><\/a><br \/>\n<a href=\"https:\/\/tom.tomwork.net\/wp-content\/uploads\/2022\/04\/pic15147262351.jpg\"><img loading=\"lazy\" decoding=\"async\" onerror=\"this.src='https:\/\/tom.tomwork.net\/wp-content\/uploads\/2020\/11\/no-picture-available-icon-1.png'\" style=\"border: 0px currentcolor; display: inline; background-image: none;\" title=\"pic1514726235[1]\" src=\"https:\/\/tom.tomwork.net\/wp-content\/uploads\/2022\/04\/pic15147262351_thumb.jpg\" alt=\"pic1514726235[1]\" width=\"1079\" height=\"1613\" border=\"0\" \/><\/a><a href=\"https:\/\/tom.tomwork.net\/wp-content\/uploads\/2022\/04\/o42.jpg\"><br \/>\n<\/a><a href=\"https:\/\/tom.tomwork.net\/wp-content\/uploads\/2022\/04\/o23.jpg\"><img loading=\"lazy\" decoding=\"async\" onerror=\"this.src='https:\/\/tom.tomwork.net\/wp-content\/uploads\/2020\/11\/no-picture-available-icon-1.png'\" style=\"margin: 0px; display: inline; background-image: none;\" title=\"o2[3]\" src=\"https:\/\/tom.tomwork.net\/wp-content\/uploads\/2022\/04\/o23_thumb.jpg\" alt=\"o2[3]\" width=\"16\" height=\"11\" border=\"0\" \/><\/a><\/p>\n<p><a href=\"https:\/\/tom.tomwork.net\/wp-content\/uploads\/2022\/04\/o111.jpg\"><img loading=\"lazy\" decoding=\"async\" onerror=\"this.src='https:\/\/tom.tomwork.net\/wp-content\/uploads\/2020\/11\/no-picture-available-icon-1.png'\" style=\"margin: 0px; display: inline; background-image: none;\" title=\"o1[11]\" src=\"https:\/\/tom.tomwork.net\/wp-content\/uploads\/2022\/04\/o111_thumb.jpg\" alt=\"o1[11]\" width=\"9\" height=\"9\" border=\"0\" \/><\/a><br \/>\n<a href=\"https:\/\/tom.tomwork.net\/wp-content\/uploads\/2022\/04\/pic1514726268.gif\"><img loading=\"lazy\" decoding=\"async\" onerror=\"this.src='https:\/\/tom.tomwork.net\/wp-content\/uploads\/2020\/11\/no-picture-available-icon-1.png'\" style=\"border: 0px currentcolor; display: inline; background-image: none;\" title=\"pic1514726268\" src=\"https:\/\/tom.tomwork.net\/wp-content\/uploads\/2022\/04\/pic1514726268_thumb.gif\" alt=\"pic1514726268\" width=\"558\" height=\"375\" border=\"0\" \/><\/a><a href=\"https:\/\/tom.tomwork.net\/wp-content\/uploads\/2022\/04\/o24.jpg\"><br \/>\n<\/a><a href=\"https:\/\/tom.tomwork.net\/wp-content\/uploads\/2022\/04\/pic15147268481.jpg\"><img loading=\"lazy\" decoding=\"async\" onerror=\"this.src='https:\/\/tom.tomwork.net\/wp-content\/uploads\/2020\/11\/no-picture-available-icon-1.png'\" style=\"border: 0px currentcolor; display: inline; background-image: none;\" title=\"pic1514726848[1]\" src=\"https:\/\/tom.tomwork.net\/wp-content\/uploads\/2022\/04\/pic15147268481_thumb.jpg\" alt=\"pic1514726848[1]\" width=\"1079\" height=\"1099\" border=\"0\" \/><\/a><a href=\"https:\/\/tom.tomwork.net\/wp-content\/uploads\/2022\/04\/o24.jpg\"><br \/>\n<\/a><a href=\"https:\/\/tom.tomwork.net\/wp-content\/uploads\/2022\/04\/o34.jpg\"><img loading=\"lazy\" decoding=\"async\" onerror=\"this.src='https:\/\/tom.tomwork.net\/wp-content\/uploads\/2020\/11\/no-picture-available-icon-1.png'\" style=\"margin: 0px; display: inline; background-image: none;\" title=\"o3[4]\" src=\"https:\/\/tom.tomwork.net\/wp-content\/uploads\/2022\/04\/o34_thumb.jpg\" alt=\"o3[4]\" width=\"16\" height=\"6\" border=\"0\" \/><\/a><\/p>\n<p><a href=\"https:\/\/tom.tomwork.net\/wp-content\/uploads\/2022\/04\/o64.jpg\"><img loading=\"lazy\" decoding=\"async\" onerror=\"this.src='https:\/\/tom.tomwork.net\/wp-content\/uploads\/2020\/11\/no-picture-available-icon-1.png'\" style=\"margin: 0px; display: inline; background-image: none;\" title=\"o6[4]\" src=\"https:\/\/tom.tomwork.net\/wp-content\/uploads\/2022\/04\/o64_thumb.jpg\" alt=\"o6[4]\" width=\"7\" height=\"16\" border=\"0\" \/><\/a><\/p>\n<p>A Null Modem or &#8220;crossover&#8221; cable is used to connect to DTE devices together. For this to work, the Transmit (TxD) pin of one device needs to be connected to the Receive (RxD) pin of the other device, and vice versa.<\/p>\n<p>To enable handshaking between the two devices, the Request to Send (RTS) pin of one device must be connected to the Clear to Send (CTS) pin of the other device, and the Data Set Ready (DSR) pin is connected to the Data Terminal Ready (DTR) pin of the other.<\/p>\n<p>Null modem adapters can also be used at the end of a straight-through serial cable to cross the lines. The StarTech SCNM9FF is an example of a null modem cable.<a href=\"https:\/\/tom.tomwork.net\/wp-content\/uploads\/2022\/04\/o25.jpg\"><br \/>\n<\/a><a href=\"https:\/\/tom.tomwork.net\/wp-content\/uploads\/2022\/04\/pic1514730155.jpg\"><img loading=\"lazy\" decoding=\"async\" onerror=\"this.src='https:\/\/tom.tomwork.net\/wp-content\/uploads\/2020\/11\/no-picture-available-icon-1.png'\" style=\"border: 0px currentcolor; display: inline; background-image: none;\" title=\"pic1514730155\" src=\"https:\/\/tom.tomwork.net\/wp-content\/uploads\/2022\/04\/pic1514730155_thumb.jpg\" alt=\"pic1514730155\" width=\"880\" height=\"658\" border=\"0\" \/><\/a><a href=\"https:\/\/tom.tomwork.net\/wp-content\/uploads\/2022\/04\/o27.jpg\"><br \/>\n<\/a><a href=\"https:\/\/tom.tomwork.net\/wp-content\/uploads\/2022\/04\/pic1514994470.jpg\"><img loading=\"lazy\" decoding=\"async\" onerror=\"this.src='https:\/\/tom.tomwork.net\/wp-content\/uploads\/2020\/11\/no-picture-available-icon-1.png'\" style=\"border: 0px currentcolor; display: inline; background-image: none;\" title=\"pic1514994470\" src=\"https:\/\/tom.tomwork.net\/wp-content\/uploads\/2022\/04\/pic1514994470_thumb.jpg\" alt=\"pic1514994470\" width=\"880\" height=\"491\" border=\"0\" \/><\/a><\/p>\n<p>\u0e25\u0e31\u0e01\u0e29\u0e13\u0e30\u0e2b\u0e21\u0e32\u0e22\u0e40\u0e25\u0e02\u0e1b\u0e23\u0e30\u0e08\u0e33\u0e02\u0e32\u0e02\u0e31\u0e49\u0e27\u0e15\u0e48\u0e2d DB-9<\/p>\n<p><a href=\"https:\/\/tom.tomwork.net\/wp-content\/uploads\/2022\/04\/o124.jpg\"><img loading=\"lazy\" decoding=\"async\" onerror=\"this.src='https:\/\/tom.tomwork.net\/wp-content\/uploads\/2020\/11\/no-picture-available-icon-1.png'\" style=\"margin: 0px; display: inline; background-image: none;\" title=\"o1[24]\" src=\"https:\/\/tom.tomwork.net\/wp-content\/uploads\/2022\/04\/o124_thumb.jpg\" alt=\"o1[24]\" width=\"9\" height=\"9\" border=\"0\" \/><\/a><\/p>\n<p><a href=\"https:\/\/tom.tomwork.net\/wp-content\/uploads\/2022\/04\/o129.jpg\"><img loading=\"lazy\" decoding=\"async\" onerror=\"this.src='https:\/\/tom.tomwork.net\/wp-content\/uploads\/2020\/11\/no-picture-available-icon-1.png'\" style=\"margin: 0px; display: inline; background-image: none;\" title=\"o1[29]\" src=\"https:\/\/tom.tomwork.net\/wp-content\/uploads\/2022\/04\/o129_thumb.jpg\" alt=\"o1[29]\" width=\"9\" height=\"9\" border=\"0\" \/><\/a><br \/>\n<a href=\"https:\/\/tom.tomwork.net\/wp-content\/uploads\/2022\/04\/pic1548078238.jpg\"><img loading=\"lazy\" decoding=\"async\" onerror=\"this.src='https:\/\/tom.tomwork.net\/wp-content\/uploads\/2020\/11\/no-picture-available-icon-1.png'\" style=\"border: 0px currentcolor; display: inline; background-image: none;\" title=\"pic1548078238\" src=\"https:\/\/tom.tomwork.net\/wp-content\/uploads\/2022\/04\/pic1548078238_thumb.jpg\" alt=\"pic1548078238\" width=\"827\" height=\"1044\" border=\"0\" \/><\/a><\/p>\n","protected":false},"excerpt":{"rendered":"<p>&nbsp; &nbsp; \u0e01\u0e32\u0e23\u0e15\u0e48\u0e2d RS232 \u0e41\u0e1a\u0e1a Crossover or Null Modem \u0e40\u0e0a\u0e37\u0e48\u0e2d\u0e21 Optimod \u0e40\u0e01\u0e47\u0e1a\u0e02\u0e49\u0e2d\u0e21\u0e39\u0e25\u0e44\u0e27\u0e49\u0e14\u0e39 \u0e01\u0e32\u0e23\u0e15\u0e48\u0e2d RS232 \u0e41\u0e1a\u0e1a Crossover or Null Modem\u00a0 \u0e43\u0e0a\u0e49\u0e23\u0e35\u0e42\u0e21\u0e17\u0e40\u0e0a\u0e37\u0e48\u0e2d\u0e21 Software \u0e01\u0e31\u0e1a Optimod 8400<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"jetpack_post_was_ever_published":false,"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"_jetpack_memberships_contains_paid_content":false,"footnotes":"","jetpack_publicize_message":"","jetpack_publicize_feature_enabled":true,"jetpack_social_post_already_shared":true,"jetpack_social_options":{"image_generator_settings":{"template":"highway","default_image_id":0,"font":"","enabled":false},"version":2}},"categories":[13],"tags":[],"class_list":["post-25997","post","type-post","status-publish","format-standard","hentry","category-13"],"jetpack_publicize_connections":[],"jetpack_featured_media_url":"","jetpack_sharing_enabled":true,"jetpack_shortlink":"https:\/\/wp.me\/p6cOVM-6Lj","_links":{"self":[{"href":"https:\/\/tom.tomwork.net\/index.php?rest_route=\/wp\/v2\/posts\/25997","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/tom.tomwork.net\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/tom.tomwork.net\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/tom.tomwork.net\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/tom.tomwork.net\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=25997"}],"version-history":[{"count":2,"href":"https:\/\/tom.tomwork.net\/index.php?rest_route=\/wp\/v2\/posts\/25997\/revisions"}],"predecessor-version":[{"id":26095,"href":"https:\/\/tom.tomwork.net\/index.php?rest_route=\/wp\/v2\/posts\/25997\/revisions\/26095"}],"wp:attachment":[{"href":"https:\/\/tom.tomwork.net\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=25997"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/tom.tomwork.net\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=25997"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/tom.tomwork.net\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=25997"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}