{"product_id":"honeywell-621-9939-serial-link-module","title":"Honeywell 621-9939 Serial Link Module","description":"\u003ch1\u003eHoneywell 621-9939 Serial Link Module\u003c\/h1\u003e\n\u003cp\u003eThe \u003cstrong\u003eHoneywell 621-9939 Serial Link Module (SLM)\u003c\/strong\u003e is a communication interface module for the Honeywell IPC 620 control platform. It provides two independent serial communication channels and incorporates its own asynchronous processor with a dedicated data table, allowing communication tasks to be handled separately from the main system CPU. This architecture supports serial I\/O integration while reducing processor overhead within the control system.\u003c\/p\u003e\n\u003ch3\u003eSystem Integration\u003c\/h3\u003e\n\u003cp\u003eThe 621-9939 module is designed specifically for installation within Honeywell IPC 620 system racks. It can only be installed in slot L and\/or slot M of the chassis.\u003c\/p\u003e\n\u003cp\u003eA maximum of two Serial Link Modules can be installed in a single rack, enabling expansion of serial communication capacity while maintaining compliance with IPC 620 hardware configuration requirements.\u003c\/p\u003e\n\u003ch3\u003eCommunication Architecture\u003c\/h3\u003e\n\u003cp\u003eThe module controls two independent serial communication channels. An onboard asynchronous processor manages communication activity locally and maintains a dedicated internal data table for serial data exchange.\u003c\/p\u003e\n\u003cp\u003eBy handling communication processing independently, the module reduces the workload placed on the primary controller and provides a structured interface between the CPU and connected serial devices.\u003c\/p\u003e\n\u003ch3\u003eWiring and Network Requirements\u003c\/h3\u003e\n\u003cp\u003eProper communication line installation requires a 200 Ohm termination resistor at each end of the communication trunk line. Correct line termination helps maintain signal integrity and reliable data transmission.\u003c\/p\u003e\n\u003cp\u003eHoneywell recommends the use of high-quality shielded twisted-pair communication cable such as Belden 9729 or an equivalent cable with similar characteristics.\u003c\/p\u003e\n\u003ch3\u003eDiagnostics and Field Connections\u003c\/h3\u003e\n\u003cp\u003eThe front panel incorporates five diagnostic LEDs to provide immediate status indication during commissioning and maintenance activities. These indicators support monitoring of module power, communication status with the system CPU, and serial port transmission activity.\u003c\/p\u003e\n\u003cp\u003eField wiring is terminated through industrial terminal block connectors, providing secure connections for remote I\/O networks, operator interfaces, and other serial communication devices.\u003c\/p\u003e\n\u003ch3\u003eTechnical Specifications\u003c\/h3\u003e\n\u003ctable class=\"___1vyiefv f1ddd56o f16vktn6 f1ahpp82 f11qra4b f1uinfot fibjyge fvueend f9yszdx f1fu4s3n f3l3pb3 f10ghnd0 f8fmt76 fjvbh62 f1qrqxae f1vw5qpk fc02sbz fxawf59 fymf513 f1aoyrul f1el8yx3 f1pymoxg f1ofu761 fe6itr f7coize f1794535 f1o0pw0q fbjjl9v fk1v6el f16pyhcb f1ixlhx9 f12zef0i flu5r5u f19haqzy f1owmcxx f1oddm8q f1004tna fcoaxci fh0ee9u f15v23i2 f1dmj53 f1r1gcv9 f14z1veh ffufd3x f1ypplot f1660cg\"\u003e\n\u003ctbody\u003e\n\u003ctr class=\"firstRow\"\u003e\n\u003cth\u003eParameter\u003c\/th\u003e\n\u003cth\u003eSpecification\u003c\/th\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eModel\u003c\/td\u003e\n\u003ctd\u003e621-9939\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBrand\u003c\/td\u003e\n\u003ctd\u003eHoneywell\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eProduct Type\u003c\/td\u003e\n\u003ctd\u003eSerial Link Module\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCompatible Platform\u003c\/td\u003e\n\u003ctd\u003eHoneywell IPC 620\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eInstallation Slots\u003c\/td\u003e\n\u003ctd\u003eL and\/or M\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMaximum Modules per Rack\u003c\/td\u003e\n\u003ctd\u003e2\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCommunication Channels\u003c\/td\u003e\n\u003ctd\u003e2 independent serial channels\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eProcessor Type\u003c\/td\u003e\n\u003ctd\u003eIndependent asynchronous processor\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eInternal Data Table\u003c\/td\u003e\n\u003ctd\u003eDedicated communication data table\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eLine Termination\u003c\/td\u003e\n\u003ctd\u003e200 Ohm resistor at each trunk end\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eRecommended Cable\u003c\/td\u003e\n\u003ctd\u003eShielded twisted-pair cable\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eRecommended Cable Type\u003c\/td\u003e\n\u003ctd\u003eBelden 9729 or equivalent\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eDiagnostic Indicators\u003c\/td\u003e\n\u003ctd\u003e5 front-panel LEDs\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eField Interface\u003c\/td\u003e\n\u003ctd\u003eTerminal block connectors\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003ch3\u003eInstallation Considerations\u003c\/h3\u003e\n\u003cp\u003eThe module should only be installed in the designated IPC 620 rack positions. When deploying serial communication networks, proper trunk-line termination and cable selection are important to ensure stable operation and communication reliability.\u003c\/p\u003e\n\u003cp\u003eSystem designers should verify rack slot availability and communication channel requirements before configuring multiple Serial Link Modules within the same chassis.\u003c\/p\u003e\n\u003ch3\u003eFrequently Asked Questions\u003c\/h3\u003e\n\u003cp\u003e\u003cstrong\u003eQ: Which IPC 620 rack slots support the 621-9939 module?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eA: The module is designed for installation only in slot L and\/or slot M of the Honeywell IPC 620 chassis. Installation in other rack positions is not specified for this model.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eQ: How many communication channels does the module provide?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eA: The 621-9939 supports two independent serial communication channels, allowing simultaneous communication with multiple serial devices or networks.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eQ: Does the module use the main CPU for communication processing?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eA: No. The module includes an independent asynchronous processor and dedicated internal data table that perform communication processing separately from the main system CPU.\u003c\/p\u003e","brand":"Honeywell","offers":[{"title":"Default Title","offer_id":67855261761635,"sku":"621-9939","price":180.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0549\/2775\/3315\/files\/621-9928R_3.png?v=1793347753","url":"https:\/\/precisemodule.com\/products\/honeywell-621-9939-serial-link-module","provider":"Precise Module Ltd.","version":"1.0","type":"link"}