{"product_id":"allen-bradley-plc-5-1775-ka-communication-adaptor-module","title":"Allen-Bradley PLC-5 1775-KA COMMUNICATION ADAPTOR MODULE","description":"\u003cp\u003eThe \u003cstrong\u003eAllen-Bradley 1775-KA\u003c\/strong\u003e, also cataloged as the \u003cstrong\u003e1775\u003c\/strong\u003e communication adaptor module, operates as a dedicated hardware component for bridging PLC-3 processors onto the Allen-Bradley Data Highway peer-polled network within legacy 1775 chassis systems.\u003c\/p\u003e\n\u003ch3\u003eCatalog Number Decoding\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003e1775-\u003c\/strong\u003e: PLC-3 family chassis and interface module series\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eKA\u003c\/strong\u003e: Data Highway (DH) communication adaptor, PLC-3 to DH link, standalone 115\/230 VAC powered\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eHardware Specifications\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\u003e1775-KA\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\u003e1.8 kg\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eShipping Dimensions\u003c\/td\u003e\n\u003ctd\u003e40.6 x 5.1 x 27.9 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\u003eStorage Temp\u003c\/td\u003e\n\u003ctd\u003e-40 to 85 deg C\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eHumidity\u003c\/td\u003e\n\u003ctd\u003e5-95 % RH non-condensing\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003ePower Requirement\u003c\/td\u003e\n\u003ctd\u003e115\/230 VAC +\/-15 %, 50\/60 Hz\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003ePower Consumption\u003c\/td\u003e\n\u003ctd\u003e35 W\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eIsolation Voltage\u003c\/td\u003e\n\u003ctd\u003e1500 VAC\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eNetwork Interface\u003c\/td\u003e\n\u003ctd\u003eData Highway (DH), 57 kbps peer-polled trunk\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCable Termination\u003c\/td\u003e\n\u003ctd\u003e75 ohm resistor network at physical ends of DH coax (1770-CD)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eStatus Indicators\u003c\/td\u003e\n\u003ctd\u003eModule OK, DH active, PLC-3 link LEDs\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003c\/figure\u003e\n\u003ch3\u003ePLC-3 Backplane Coupling and Protocol Translation\u003c\/h3\u003e\n\u003cp\u003eThe 1775-KA is not a rack-plugged PLC-5 module; it mounts in a 1775 PLC-3 chassis bay and draws its own 115\/230 VAC from a separate feed, not from the 1775 backplane DC bus. It performs asynchronous framing conversion between the PLC-3 peripheral bus and the DH half-duplex 57 kbps tokenless peer-poll protocol. There is no firmware flash path—personality is mask-ROM fixed per revision tape label. I\/O density scaling does not apply; one 1775-KA services exactly one PLC-3 processor node on the DH trunk. EtherNet\/IP or Profinet licences are absent; this is pre-ControlLogix legacy serial networking. Backplane bus velocity licence is irrelevant—the module talks DH coax, not a backplane.\u003c\/p\u003e\n\u003ch3\u003eOrdering Info\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e1 x 1775-KA communication adaptor module (discontinued, surplus sealed unit)\u003c\/li\u003e\n\u003cli\u003e1 x 1770-CD DH coax interconnect lead set (sold separately, not included)\u003c\/li\u003e\n\u003cli\u003e2 x 75 ohm termination resistors (field-supplied per DH segment end rule)\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003ePanel and Coax Installation Rules\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eBolt module into 1775 chassis slot with factory mounting ears; torque 2.3 N·m, do not cantilever without bottom bracket.\u003c\/li\u003e\n\u003cli\u003eFeed 115 VAC or 230 VAC (select via rear voltage selector) from isolated control transformer, 35 W minimum, separate from 24 VDC sensor supply.\u003c\/li\u003e\n\u003cli\u003eRun DH coax (1770-CD) with 75 ohm characteristic impedance; terminate both physical ends with 75 ohm resistors, no mid-span taps beyond 32 nodes.\u003c\/li\u003e\n\u003cli\u003eKeep DH coax 200 mm from 480 VAC power trays; cross at 90 deg only.\u003c\/li\u003e\n\u003cli\u003eBond module chassis ground to PLC-3 cabinet ground bus with 4 mm² green\/yellow, single point, no shield daisy-chain.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eFrequently Asked Questions\u003c\/h3\u003e\n\u003cp\u003eQ: Can the 1775-KA be installed into a PLC-5 1785 chassis?\u003c\/p\u003e\n\u003cp\u003eA: No. Physical card height and edge connector differ. PLC-5 uses 1785-KA or 1771-KF\/KE for DH+. Forcing 1775-KA into 1785 backplane misaligns the 115 VAC power tab and bends the DH header pins.\u003c\/p\u003e\n\u003cp\u003eQ: Is the module hot-swappable on a live PLC-3?\u003c\/p\u003e\n\u003cp\u003eA: No. The 1775-KA carries line voltage on the rear connector. Removing under power arcs the 115\/230 VAC tabs and corrupts the DH peer table; PLC-3 logs node loss F61. De-energize chassis first.\u003c\/p\u003e\n\u003cp\u003eQ: What happens if 75 ohm terminators are omitted on DH coax?\u003c\/p\u003e\n\u003cp\u003eA: Signal reflects at 57 kbps; peer-poll collisions rise, CRC errors climb, PLC-3 DH read\/write times out at 750 ms. Both ends must be terminated, mid-trunk tee joints are not substitutes.\u003c\/p\u003e\n\u003cp\u003eQ: Does 1775-KA support DH+ (Data Highway Plus)?\u003c\/p\u003e\n\u003cp\u003eA: No. It speaks original DH (57 kbps, half-duplex). DH+ uses 1785-KA in PLC-5 or 1770-KF2 bridges. Mixing DH and DH+ coax on one 1775-KA port produces no link LED and silent timeout.\u003c\/p\u003e\n\u003cp\u003eQ: Power draw when idle vs active?\u003c\/p\u003e\n\u003cp\u003eA: 35 W max at 230 VAC full DH traffic. Idle (PLC-3 stopped, DH quiet) draws approx 18 W from the 115 VAC rail. Undersizing feed transformer below 50 VA causes brownout reset at power-on surge.\u003c\/p\u003e\n\u003cp\u003eQ: Can firmware be updated in field?\u003c\/p\u003e\n\u003cp\u003eA: No. Mask-ROM locked, no flash socket. Revision changes require factory board swap. Surplus units carry the tape label revision (typically Rev B\/C); mixing revisions on one DH trunk is allowed but config file must match node table.\u003c\/p\u003e\n\u003cp\u003eQ: Maximum DH trunk length with 1775-KA?\u003c\/p\u003e\n\u003cp\u003eA: 7000 cable-feet (2133 m) using 1770-CD coax, 57 kbps, 75 ohm terminated, 32 nodes max. Exceeding length degrades poll margin; repeaters (1770-KF2) required beyond that, not another 1775-KA.\u003c\/p\u003e\n\u003cp\u003eQ: Isolation rating between DH coax and AC mains?\u003c\/p\u003e\n\u003cp\u003eA: 1500 VAC dielectric withstand for 1 minute per Allen-Bradley 1775 bulletin. DH shield is capacitively coupled to chassis ground; do not tie DH shield to both cabinet ground and remote end shield simultaneously (ground loop).\u003c\/p\u003e","brand":"Allen-Bradley","offers":[{"title":"Default Title","offer_id":46066445516973,"sku":"1775-KA","price":88.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0733\/1613\/9181\/files\/1775-KA_2-1.jpg?v=1786347794","url":"https:\/\/www.maxwellplc.com\/ru\/products\/allen-bradley-plc-5-1775-ka-communication-adaptor-module","provider":"Maxwell PLC Ltd","version":"1.0","type":"link"}