{"product_id":"1771-db-allen-bradley-plc-5-basic-module","title":"1771-DB Allen-Bradley PLC-5 Basic Module","description":"\u003cp\u003eThe \u003cstrong\u003eAllen-Bradley 1771-DB\u003c\/strong\u003e, also cataloged as the \u003cstrong\u003e1771-DB\u003c\/strong\u003e Basic Module, operates as a dedicated hardware component for custom ASCII string processing and serial communication execution within PLC-5 I\/O chassis architecture.\u003c\/p\u003e\n\u003ch3\u003eSerial Interface \u0026amp; Functional Designator Breakdown\u003c\/h3\u003e\n\u003cp\u003eThe \u003cstrong\u003eAllen-Bradley 1771-DB\u003c\/strong\u003e module occupies a single slot in any 1771 I\/O chassis. It provides dedicated serial ports including DH485, PRT1, and PRT2 for direct interfacing with serial printers, ASCII terminals, and barcode readers. The internal coprocessor executes BASIC language algorithms independent of the main controller sweep, offloading ASCII manipulation tasks from the primary processor.\u003c\/p\u003e\n\u003ch3\u003eEngineering \u0026amp; Physical Parameters\u003c\/h3\u003e\n\u003cfigure\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\u003e1771-DB\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\u003e0.3 kg\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eShipping Dimensions\u003c\/td\u003e\n\u003ctd\u003e5.1 x 27.9 x 17.8 cm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOperating Temp\u003c\/td\u003e\n\u003ctd\u003e0 to 60 deg C\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003ePower Consumption\u003c\/td\u003e\n\u003ctd\u003e3.75 W (0.75 A at 5 VDC backplane current)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCommunication Ports\u003c\/td\u003e\n\u003ctd\u003eDH485, PRT1, PRT2\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBackplane Current\u003c\/td\u003e\n\u003ctd\u003e0.75 A at 5 VDC\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eChassis Compatibility\u003c\/td\u003e\n\u003ctd\u003e1771 I\/O Chassis\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003c\/figure\u003e\n\u003ch3\u003eBackplane Integration \u0026amp; Data Exchange Mechanics\u003c\/h3\u003e\n\u003cp\u003eThe module communicates with the PLC-5 processor across the 1771 backplane bus using block transfer read (BTR) and block transfer write (BTW) instructions. Communication streams bridge serial protocols with network architectures like Profinet \/ EtherNet\/IP deterministic networks via controller gateway modules. Firmware flash compatibility maintains program execution synchronization and enables flexible I\/O density scaling within legacy 1771 chassis racks.\u003c\/p\u003e\n\u003ch3\u003ePackage Delivery Contents\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e1 x Allen-Bradley 1771-DB Basic Module Assembly\u003c\/li\u003e\n\u003cli\u003e1 x Field Wiring Arm\u003c\/li\u003e\n\u003cli\u003e1 x Instruction Sheet\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eField Cabinet Installation Procedures\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eDe-energize the 1771 chassis backplane supply before inserting or removing the module from the rack slot.\u003c\/li\u003e\n\u003cli\u003eAlign the circuit board with the chassis card guides and push firmly until the locking latch engages the chassis frame.\u003c\/li\u003e\n\u003cli\u003eWire serial communication lines using shielded twisted-pair cables connected to the port screw terminals.\u003c\/li\u003e\n\u003cli\u003eConnect cable drain wires to the chassis protective earth ground terminal to suppress electromagnetic interference.\u003c\/li\u003e\n\u003cli\u003eMaintain minimum clearances around the 1771 rack to ensure ambient enclosure temperatures remain between 0 and 60 deg C.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eField Engineering FAQ\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cp\u003eWhat backplane current does the 1771-DB module draw from the 1771 chassis power supply?\u003c\/p\u003e\n\u003cp\u003eThe 1771-DB module draws a maximum current of 0.75 A at 5 VDC directly from the backplane power rail.\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eWhat communication ports are available on the front interface panel of the module?\u003c\/p\u003e\n\u003cp\u003eThe module provides three communication ports labeled DH485, PRT1, and PRT2 for serial device connectivity.\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eCan the 1771-DB module be removed or inserted while the rack power is turned on?\u003c\/p\u003e\n\u003cp\u003eNo, removing or inserting the module while the backplane is energized can cause electrical damage or system faults.\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eHow does the PLC-5 processor exchange data tables with the BASIC module coprocessor?\u003c\/p\u003e\n\u003cp\u003eData transfers between the PLC-5 processor and the 1771-DB module occur via Block Transfer Read (BTR) and Write (BTW) routines.\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eWhat function does the internal coprocessor perform relative to the main PLC-5 CPU?\u003c\/p\u003e\n\u003cp\u003eIt offloads BASIC program execution and ASCII string handling, running independently of the main controller scan cycle.\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eHow are serial cable shields grounded during field installation?\u003c\/p\u003e\n\u003cp\u003eCable shield braids must be connected to a single-point chassis ground lug to prevent ground loops and noise injection.\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eWhat operating temperature envelope applies to the 1771-DB hardware in an enclosure?\u003c\/p\u003e\n\u003cp\u003eThe hardware operates within ambient cabinet temperatures ranging from 0 deg C up to 60 deg C without external cooling.\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eHow are communication protocols aligned with system firmware updates?\u003c\/p\u003e\n\u003cp\u003ePort settings and program memory interface through system firmware flash compatibility routines managed in user logic.\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"Allen-Bradley","offers":[{"title":"Default Title","offer_id":46066442993837,"sku":"1771-DB","price":88.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0733\/1613\/9181\/files\/allen-bradley_1771-db.jpg?v=1786545106","url":"https:\/\/www.maxwellplc.com\/ga\/products\/1771-db-allen-bradley-plc-5-basic-module","provider":"Maxwell PLC Ltd","version":"1.0","type":"link"}