{"product_id":"allen-bradley-1745-e156-i-o-expansion-unit","title":"Allen Bradley 1745-E156 I\/O Expansion Unit","description":"\u003cp\u003eThe \u003cstrong\u003eAllen-Bradley 1745-E156\u003c\/strong\u003e, also cataloged as the \u003cstrong\u003e1745-E156\u003c\/strong\u003e I\/O Expansion Unit, operates as a dedicated hardware component for discrete signal extension within SLC 150 architecture systems.\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\u003e1745-E156\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\u003e4.00 lbs\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eDimensions\u003c\/td\u003e\n\u003ctd\u003e10.0 x 6.5 x 4.0 inches\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\u003e15 VA maximum\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eController Series\u003c\/td\u003e\n\u003ctd\u003eSLC 150 Programmable Logic Controller\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eModule Category\u003c\/td\u003e\n\u003ctd\u003ePLC Expansion Unit \/ Rack\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eInterconnect Interface\u003c\/td\u003e\n\u003ctd\u003eRibbon Expansion Bus\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003c\/figure\u003e\n\u003ch3\u003eBackplane Bus Interconnect \u0026amp; I\/O Density Scaling\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eDeterminism \u0026amp; Bus Execution\u003c\/strong\u003e: The 1745-E156 expansion unit connects to the primary SLC 150 controller via a ribbon cable bus, extending system I\/O point capacity while executing logic scans synchronously with the main CPU.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFirmware Flash Compatibility \u0026amp; Addressing\u003c\/strong\u003e: Hardware registers map directly into the base controller memory tables, allowing firmware execution without additional network protocol configuration overhead.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eGalvanic Isolation \u0026amp; Noise Suppression\u003c\/strong\u003e: Integrated channel optocouplers isolate backplane logic circuits from transient field noise and line surges across field terminals.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eFrequently Asked Questions\u003c\/h3\u003e\n\u003cp\u003eQ: Can the 1745-E156 expansion unit be connected or removed while the main processor is powered?\u003c\/p\u003e\n\u003cp\u003eA: No. Hot-swapping is prohibited. Master AC or DC power to the controller base unit must be disconnected before connecting or disconnecting the expansion bus ribbon cable.\u003c\/p\u003e\n\u003cp\u003eQ: How is synchronization maintained between the primary SLC 150 unit and the 1745-E156 module?\u003c\/p\u003e\n\u003cp\u003eA: Bus clock and frame timing pass directly through the dedicated ribbon interconnect cable, maintaining deterministic I\/O updates during each processor scan cycle.\u003c\/p\u003e\n\u003ch3\u003eField Installation Guidelines\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003ePhysical Mounting \u0026amp; Spacing\u003c\/strong\u003e: Mount the chassis securely to the control enclosure panel using standard mounting hardware. Maintain a minimum vertical clearance of 50 mm (2 inches) above and below the housing for unhindered air convection.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eInterconnect Cable Setup\u003c\/strong\u003e: Ensure the multi-conductor ribbon bus cable is locked into the expansion headers on both the main processor and the 1745-E156 chassis prior to applying circuit power.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eGrounding \u0026amp; Cable Separation\u003c\/strong\u003e: Attach a low-impedance copper ground wire from the frame ground terminal directly to the central cabinet earth bus. Separate low-voltage DC lines from high-voltage AC lines by at least 200 mm to avoid inductive noise coupling.\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"Allen-Bradley","offers":[{"title":"Default Title","offer_id":45340469854323,"sku":"1745-E156","price":88.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0644\/4348\/2227\/files\/screenshot_2026-08-11_09-14-49_263fe103-d20a-4ec5-ae5f-b790d5eeba3a.png?v=1786411661","url":"https:\/\/www.dcssupplier.com\/products\/allen-bradley-1745-e156-i-o-expansion-unit","provider":"DcsSupplier Limited","version":"1.0","type":"link"}