{"product_id":"yokogawa-alr121-s01-series-field-control-communication-module","title":"Yokogawa ALR121-S01 series field control communication module","description":"\u003ch2\u003eYOKOGAWA ALR121-S01 Serial Communication Module\u003c\/h2\u003e\n\u003cp\u003eConfigured for serial data exchange within CENTUM VP and ProSafe-RS control networks, the \u003cstrong\u003eYOKOGAWA ALR121-S01\u003c\/strong\u003e (\u003cstrong\u003eALR121\u003c\/strong\u003e Serial Communication Module) provides direct physical and electrical execution of RS-422\/RS-485 communication protocols between Field Control Stations (FCS) and peripheral field devices.\u003c\/p\u003e\n\u003ch3\u003eHardware Specifications\u003c\/h3\u003e\n\u003cfigure class=\"table\"\u003e\n\u003ctable\u003e\n\u003cthead\u003e\n\u003ctr\u003e\n\u003cth\u003e\u003cstrong\u003eParameter\u003c\/strong\u003e\u003c\/th\u003e\n\u003cth\u003e\u003cstrong\u003eSpecification\u003c\/strong\u003e\u003c\/th\u003e\n\u003c\/tr\u003e\n\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eModel\u003c\/td\u003e\n\u003ctd\u003eALR121-S01\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBrand\u003c\/td\u003e\n\u003ctd\u003eYokogawa\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOrigin\u003c\/td\u003e\n\u003ctd\u003eSingapore\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eWeight\u003c\/td\u003e\n\u003ctd\u003e0.3 kg\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eDimensions\u003c\/td\u003e\n\u003ctd\u003e126.7 x 32.8 x 130 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOperating Temp\u003c\/td\u003e\n\u003ctd\u003e-20 deg C to +60 deg C\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003ePower Consumption\u003c\/td\u003e\n\u003ctd\u003e\u0026lt; 5 W\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eInterface\u003c\/td\u003e\n\u003ctd\u003eRS-422 \/ RS-485\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003c\/figure\u003e\n\u003ch3\u003eProcess Control and Communication Connectivity\u003c\/h3\u003e\n\u003cp\u003eThe ALR121 module facilitates integration with field control stations, supporting diverse protocol suites including Modbus, MELSEC-A, and YS instrument communication. The unit architecture enables high-integrity data transfer, supporting both point-to-point and multipoint communication architectures. To ensure process continuity, the system allows for dual-redundant module configuration, which provides automatic switchover capabilities in the event of primary channel failure. The module maintains signal integrity through channel-to-channel isolation and robust EMI resistance, which is standard for high-density Yokogawa DCS environments. Operators must ensure correct termination at the terminal block to maintain impedance matching for the 1200 m maximum transmission distance.\u003c\/p\u003e\n\u003ch3\u003eFrequently Asked Questions\u003c\/h3\u003e\n\u003cp\u003eQ: Can the ALR121 support simultaneous communication protocols on both ports?\u003c\/p\u003e\n\u003cp\u003eA: Yes, the ALR121 allows for independent protocol configuration on its dual ports. Each port can be assigned specific communication definitions, provided the total number of definitions does not exceed the module capacity constraints set by the connected FCS.\u003c\/p\u003e\n\u003cp\u003eQ: How is the redundancy switchover managed when using dual modules?\u003c\/p\u003e\n\u003cp\u003eA: Redundancy is managed by the Field Control Station (FCS). When the primary module experiences a hardware heartbeat loss or communication timeout, the FCS automatically switches process data polling to the secondary module without requiring operator intervention.\u003c\/p\u003e\n\u003ch3\u003eField Installation Guidelines\u003c\/h3\u003e\n\u003col\u003e\n\u003cli\u003e\n\u003cstrong\u003eMounting:\u003c\/strong\u003e Seat the module firmly into the designated slot on the node unit backplane. Engage the top and bottom locking levers to ensure high-pressure contact with the module bus connectors.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWiring:\u003c\/strong\u003e Use shielded twisted-pair cabling for RS-485\/RS-422 signals. Connect the cable shield to the designated functional ground terminal on the module interface plate to mitigate electromagnetic noise.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eTermination:\u003c\/strong\u003e For long-distance multipoint segments, install 120 Ohm termination resistors at both ends of the RS-485 transmission line to prevent signal reflections.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eConfiguration:\u003c\/strong\u003e Utilize the Centum VP engineering workstation to assign the correct port parameters, baud rate, and parity settings. Verify the physical link status LEDs on the module front panel after initialization.\u003c\/li\u003e\n\u003c\/ol\u003e","brand":"Yokogawa","offers":[{"title":"Default Title","offer_id":43624060551258,"sku":"ALR121-S01","price":99.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0710\/5957\/0778\/files\/392._179a373c-20a6-4945-b11b-6096ad4af1e3.jpg?v=1783579052","url":"https:\/\/www.spareoil.com\/ar\/products\/yokogawa-alr121-s01-series-field-control-communication-module","provider":"SpareOil Automation","version":"1.0","type":"link"}