{"product_id":"1771-obd-allen-bradley-plc-5-16-point-digital-output-module","title":"1771-OBD Allen-Bradley PLC-5 16 Point Digital Output Module","description":"\u003cp\u003eThe \u003cstrong\u003eAllen-Bradley 1771-OBD\u003c\/strong\u003e, also cataloged as the \u003cstrong\u003e1771-OBD\u003c\/strong\u003e Digital Output Module, operates as a dedicated hardware component for sourcing 16 discrete DC output signals within PLC-5 chassis backplane networks.\u003c\/p\u003e\n\u003ch3\u003eCatalog Number Matrix\u003c\/h3\u003e\n\u003cfigure\u003e\n\u003ctable\u003e\n\u003cthead\u003e\n\u003ctr\u003e\n\u003cth\u003eVariant\u003c\/th\u003e\n\u003cth\u003eDescription\u003c\/th\u003e\n\u003c\/tr\u003e\n\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003e1771-OBD\u003c\/td\u003e\n\u003ctd\u003eBase catalog number, 16-point DC output module\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e1771-OBD\/B\u003c\/td\u003e\n\u003ctd\u003eRevision B firmware hardware\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e1771-OBD\/C\u003c\/td\u003e\n\u003ctd\u003eRevision C firmware hardware\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e1771-0BD\u003c\/td\u003e\n\u003ctd\u003eAlternate spare part designation\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003c\/figure\u003e\n\u003ch3\u003eTechnical Data\u003c\/h3\u003e\n\u003cfigure\u003e\n\u003ctable\u003e\n\u003cthead\u003e\n\u003ctr\u003e\n\u003cth\u003eParameter\u003c\/th\u003e\n\u003cth\u003eSpecification\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\u003e1771-OBD\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBrand\u003c\/td\u003e\n\u003ctd\u003eAllen-Bradley\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOrigin\u003c\/td\u003e\n\u003ctd\u003eUSA\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eWeight\u003c\/td\u003e\n\u003ctd\u003e0.42 kg\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eShipping Dimensions\u003c\/td\u003e\n\u003ctd\u003e3 x 14.5 x 25.3 cm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOperating Voltage Range\u003c\/td\u003e\n\u003ctd\u003e10-60 VDC\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eNominal Output Voltage\u003c\/td\u003e\n\u003ctd\u003e48 VDC\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMax Output Current per Point\u003c\/td\u003e\n\u003ctd\u003e2 A\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMinimum Load Current\u003c\/td\u003e\n\u003ctd\u003e2.5 mA\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003ePower Dissipation\u003c\/td\u003e\n\u003ctd\u003e15.6 W\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMounting\u003c\/td\u003e\n\u003ctd\u003eRack Mountable\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTariff Code\u003c\/td\u003e\n\u003ctd\u003e8537101190\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003c\/figure\u003e\n\u003ch3\u003eBackplane Communication and I\/O Density Scaling\u003c\/h3\u003e\n\u003cp\u003eThe 1771-OBD interfaces with the PLC-5 processor via the 1771 I\/O chassis backplane. Backplane bus communication velocity licenses govern data exchange between the adapter module and the processor scan table. I\/O density scaling is constrained by chassis slot count and total backplane current budget. Each output point sources current to field devices through the chassis power supply. Firmware flash compatibility between revision B and revision C hardware permits in-chassis replacement without program modification when the processor operating system revision matches the module's electronic keying requirements.\u003c\/p\u003e\n\u003ch3\u003eOrdering Information\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e1 x 1771-OBD module (base unit)\u003c\/li\u003e\n\u003cli\u003e1 x Installation instruction sheet\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eMounting and Wiring\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eInstall module into any available 1771 I\/O chassis slot\u003c\/li\u003e\n\u003cli\u003eSecure module with chassis mounting latches\u003c\/li\u003e\n\u003cli\u003eRoute field wiring to the removable terminal block\u003c\/li\u003e\n\u003cli\u003eVerify chassis ground connection before applying power\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eFrequently Asked Questions\u003c\/h3\u003e\n\u003cp\u003e\u003cstrong\u003eDoes the 1771-OBD support hot-swap removal under load?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eNo. Remove power from the 1771 I\/O chassis before extracting or inserting the module. Backplane connectors carry live DC voltage and inductive load energy. Hot-swap operation is not supported by the PLC-5 platform hardware design.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWhat is the minimum load current requirement per output point?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eEach output circuit requires a minimum load current of 2.5 mA to maintain proper transistor saturation. Loads below this threshold may cause incomplete turn-on or erratic switching behavior at the output terminals.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eCan the 1771-OBD operate at 24 VDC nominal field supply?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eYes. The operating voltage range spans 10-60 VDC. A 24 VDC field supply is fully within specification. The nominal rating of 48 VDC represents the design center, not an exclusivity limit.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWhat is the total power dissipation at full 2 A per point load?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eTotal power dissipation is specified as 15.6 W maximum under full electrical load across all 16 points. Individual point dissipation depends on the voltage drop across the output transistor and the connected load current.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eIs the 1771-OBD\/B firmware compatible with 1771-OBD\/C chassis firmware?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eYes. Firmware flash compatibility exists between revision B and revision C hardware. The processor compares the module's electronic keying data against the I\/O configuration file. Mismatched keying triggers a fault if software keying enforcement is active.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWhat gauge wire is permitted for the terminal block connections?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eUse copper wire rated for 60 deg C or 75 deg C. Recommended gauge ranges from 14 AWG to 22 AWG stranded or solid conductor. Torque terminal screws to the manufacturer specification to prevent thermal rise at connection points.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eHow many modules can be installed in a single 1771 chassis?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eChassis are available in 4-slot, 8-slot, 12-slot, and 16-slot configurations. Total module count is limited by the chassis slot capacity and the power supply's ability to source backplane current for all installed modules simultaneously.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eDoes the module provide channel-to-channel isolation?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eNo. All 16 output points share a common internal DC supply rail. Isolation exists only between the backplane logic and the output power circuit. Field wiring must account for this common connection when interfacing with external devices.\u003c\/p\u003e","brand":"Allen-Bradley","offers":[{"title":"Default Title","offer_id":46066444009645,"sku":"1771-OBD","price":88.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0733\/1613\/9181\/files\/allen-bradley_1771-obd.jpg?v=1786890527","url":"https:\/\/www.maxwellplc.com\/ga\/products\/1771-obd-allen-bradley-plc-5-16-point-digital-output-module","provider":"Maxwell PLC Ltd","version":"1.0","type":"link"}