{"product_id":"serial-communication-module-yokogawa-alr121","title":"Serial Communication Module YOKOGAWA ALR121","description":"\u003cp\u003eConfigured for serial subsystem data exchange in CENTUM and ProSafe-RS control platforms, the \u003cstrong\u003eYOKOGAWA ALR121\u003c\/strong\u003e (\u003cstrong\u003eALR121\u003c\/strong\u003e Communication Module) provides direct physical\/electrical execution. This hardware component serves as a dual-port serial gateway utilized to execute Modbus (RTU\/ASCII) and general subsystem communication across distributed control system platforms.\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\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\u003eJAPAN\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\u003e2.2 cm x 12.4 cm x 12.6 cm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOperating Temp\u003c\/td\u003e\n\u003ctd\u003e-20 to 70 deg C\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003ePower Consumption\u003c\/td\u003e\n\u003ctd\u003e0.5 A (at 5 VDC)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eInterface Type\u003c\/td\u003e\n\u003ctd\u003eRS-422 \/ RS-485 (4-wire)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTransmission Speed\u003c\/td\u003e\n\u003ctd\u003e1200 to 38400 bps\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eConnection Mode\u003c\/td\u003e\n\u003ctd\u003eHalf-duplex\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003c\/figure\u003e\n\u003ch3\u003ePLC\/DCS Integration and Communication Characteristics\u003c\/h3\u003e\n\u003cp\u003eThe ALR121 module is engineered to provide deterministic serial data bridging between the field control station (FCS) or safety control station (SCS) and external subsystems. It supports both point-to-point (RS-422) and multipoint (RS-485) configurations, allowing for integration with diverse industrial devices, including PLCs and third-party instrumentation. The module manages frame timing with a fixed 1 ms lag after transmission to ensure bus stability, and it supports dual-redundant communication configurations when paired with an adjacent module in the I\/O chassis to maintain high availability in critical process loops.\u003c\/p\u003e\n\u003ch3\u003eFrequently Asked Questions\u003c\/h3\u003e\n\u003cp\u003eQ: Can the two ports on the ALR121 module be configured with different communication functions?\u003c\/p\u003e\n\u003cp\u003eA: No. The two serial ports on a single ALR121 module must be configured with identical communication functions and parameters.\u003c\/p\u003e\n\u003cp\u003eQ: Is this module capable of performing hot-swaps during system operation?\u003c\/p\u003e\n\u003cp\u003eA: Yes, hot-swap replacement is supported when the module is installed in a redundant configuration; however, standard safety protocols should be followed to isolate the communication link before physical removal.\u003c\/p\u003e\n\u003ch3\u003eField Installation Guidelines\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eEnsure the control station is powered down before seating the ALR121 into the base plate to prevent electrical short-circuits on the backplane bus.\u003c\/li\u003e\n\u003cli\u003eUse shielded, twisted-pair cabling for all serial runs; terminate cable shields only at the specified system grounding points to avoid ground loops.\u003c\/li\u003e\n\u003cli\u003eFor RS-485 multipoint networks, ensure that 120 ohm termination resistors are installed at both physical ends of the transmission line to suppress signal reflections.\u003c\/li\u003e\n\u003cli\u003eVerify that the transmission distance does not exceed 1200 m for RS-485 segments to maintain signal integrity and meet data throughput specifications.\u003c\/li\u003e\n\u003cli\u003eConfirm that the module locking mechanism is fully engaged after installation to ensure low-resistance contact with the backplane connectors.\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"Yokogawa","offers":[{"title":"Default Title","offer_id":49797378048252,"sku":"ALR121","price":99.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0787\/9983\/1292\/files\/ALR1211.jpg?v=1783993710","url":"https:\/\/www.electronicplc.com\/es\/products\/serial-communication-module-yokogawa-alr121","provider":"Electronic PLC","version":"1.0","type":"link"}