PDF Electric and Supply



Buy Now1771-DCM
1771-DCM Wiring

Rated 4.8/5 based on 10 ratings.
  • 1771-DCM
  • 1771-DCM Wiring
PDF Electric & Supply Company is not an authorized distributor, reseller or representative of the products featured on this website. All product names, trademarks, brands and logos used on this site are the property of their respective owners. The depiction, description or sale of products featuring these names, trademarks, brands and logos is for identification purposes only and is not intended to indicate any affiliation with or authorization by any rights holder.

The Allen Bradley 1771-DCM is a Direct Communication Module for the PLC-5 system. This module occupies a single slot in the I/O chassis. The 1771-DCM moderates communication between local processors, which are mounted on the I/O chassis and the supervisory processor. Additionally, the 1771-DCM enables direct communication between a remotely configured processor and a supervisory processor. The 1771-DCM can accommodate a discrete data transfer mode with 8 words and a block data transfer mode that has 64 words, plus a single status word. The 1771-DCM uses the backplane to communicate with the processor. The processor then regards the 1771-DCM as an intelligent Input/Output module. The scanner adapter link is used by a remote processor to initiate communication to the 1771-DCM through the backplane using block transfer.


The 1771-DCM is connected to other remote I/O chassis using the trunkline or the daisy chain hook-up. When connected using the daisy chain, each I/O chassis is spliced into the serial I/O channel using a 150 Ohm resistor for termination. When the trunkline hookup is used, a dropline not exceeding 100 feet in length is used to connect the 1771-DCM to the serial Input Output channel. The 1771-XG T-connector is used to interface the dropline with the trunkline. The open ends of the trunkline are terminated using the 1770-XF terminator set. The 1771-DCM has a mechanism in place to detect invalid data, insufficient data available, excessive data available, no data available, scanner communication errors, backplane errors, backplane resets, inactive outputs, and old data. The 1771-DCM has 4 indicators (PWR, SER COM, BPLN COM and DCM FLT) that help in monitoring and troubleshooting of the module. The 1771-DCM also has communication rates of 57.6k and 115.2k for 10,000 and 5,000 feet of cable, respectively. The 1771-DCM draws a current of 1.2A from the backplane. This module has a rack size setting and an I/O rack address for discrete data transfers.


Other Automation PLC-5

SKU 2170269  UPC 0799705798328

AB Direct Comm. Mod. 1771D 1771DC

Troubleshooting and Product Information for 1771-DCM

Download product information, troubleshooting guides and operation manuals to get your PLC operational.

Other Automation
PLC-5 1771-DCM
Weight: 2 Lbs
Dimensions: 10"x12"x2"In
Call Now
Ships Today In Stock, Ships Today
In Stock
Call Now 1-800-360-6802
Weight: 2 Lbs
Dimensions: 10"x12"x2"In
In Stock
Ships Today
FAST Quote

Other 1771-DCM

Available Revisions:

1771-DCM , CIM1771-DCM

    Need To Order A Specific Revision?

    Give us a call at 1-800-360-6802 or 1-919-535-3180.

    We can help you with your Revision specific needs.

    Free Overnight delivery on orders over $500!

    What is New Surplus?

    These “New Surplus” units are a great cost saving alternative. This product is sealed in the original manufacturer’s packaging with all sub-assemblies and documentation. May indicate older date code. Comes with a PDF Supply 3-year warranty.

    Free Overnight delivery on orders over $500!

    What is Surplus New?

    Surplus New - New unused and includes all sub-assemblies and documentation. Product may ship in manufacturer or PDF Supply packaging. May indicate older date code. Includes a PDF Supply 3 Year Warranty.

    Free Overnight delivery on orders over $500!

    What is Reconditioned?

    Reconditioned products from PDF Supply are a cost-effective alternative to new and obsoleted PLC products. Every part is reconditioned down to the circuit board level and updated to the latest revision. All parts are thoroughly inspected and hand-cleaned before being functionally tested in a fully configured system.

    Our Reconditioned Products always come with a PDF Supply 2-Year Warranty.

    Free Overnight delivery on orders over $500!

    What is a Verified Substitute?

    A verified substitute new product is a "drop in" replacement designed with identical specifications as the OEM product. It will meet all electrical and dimensional charactertics at a substanstially reduced price.

    Free Overnight delivery on orders over $500!

    Download Lastest Documentation

    Please visit this manufacturer's website to download the lastest manuals and datasheets.

    Lowest Price Guarantee

    We stand behind our prices with a lowest price guarantee. If you find a legacy GE PLC part advertised for less on an authorized GE PLC distributor website, simply contact us and send us a link to the lower advertised price. We will match that price and ship overnight FREE. The item must be in stock, in similar condition and be able to ship same day.

    Free Shipping

    FREE Overnight Delivery for Continental US orders over $500!

    FREE Ground Delivery for Continental US orders under $500!

    US orders placed Monday - Friday before 5pm EST will ship same day.

    Canada/Mexico orders placed Monday - Friday before 3:30pm EST will ship same day.

    International orders will ship the following business day.