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Catalog # 303143 - Model 4143 DB25 Automatic Fallback A/B Switch

    DB25 Automatic Fallback A/B SwitchDB25 Automatic Fallback A/B SwitchDB25 Automatic Fallback A/B SwitchDB25 Automatic Fallback A/B Switch
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    • DB25 Automatic Fallback A/B Switch
    • DB25 Automatic Fallback A/B Switch
    • DB25 Automatic Fallback A/B Switch
    • DB25 Automatic Fallback A/B Switch
Base Price:
Catalog No: 303143
Model No: 4143
Product Type:Switches: Copper
Cable Type/Port Connector:DB25 Switch Ports
Channels per Switch Chassis:1
Electronic Switches/Power Required:PathWay® Copper
Remote Control:Auto Fallback
Auto Fallback:DB25 COMMON, Pin 9
Pins Switched:Pins 1-8 and 10-25
Local Control:Pushbutton
Protocol:Transition signals on pin 9


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Products shall be shipped F.O.B. Electro Standards' facility. Title to and risk of loss or damage to the products shall pass to you upon Electro Standards delivery of the products to a carrier for shipment. Title to software will remain with the applicable licensor. Electro Standards' prices do not include shipping and handling charges. Electro Standards reserves the right to use its own discretion in the manner and routing of shipments. Electro Standards shall be permitted to deliver products in separate lots.

Shipping Return Policy

  • To return an item, contact Electro Standards at 401-943-1164 to obtain a Return Material Authorization (RMA) number. RMA numbers are valid for 30 days after the date of the shipment and cannot be extended or re-issued. We are unable to accept returns without an RMA number.
  • All returns except those of defective product are subject to a 15% restocking fee, and additional charges for handling or freight are refunded only in cases of defective products.
  • Return freight must be shipped prepaid. We recommend that you insure the package as you are responsible for risk of loss on all returned packages. We recommend that all cartons are properly packed as Electro Standards is not responsible for product damaged en route. We do not issue call tags for product returns.
  • Returned product must be clean, undamaged, and complete with all manuals, accessories, documents and packaging. The items must be in a resalable condition.
  • The product must have with it a copy of the original invoice or packing slip and the appropriate RMA paperwork.
  • If your item is not working properly, please contact Electro Standards at 401-943-1164 for help in trouble-shooting your application.
  • If the product is defective, Electro Standards will repair or replace that item (at our discretion) upon receipt and evaluation of the original product.
  • Electro Standards reserves the right to authorize product returns after 30 days from the invoice date in some cases. If the product is accepted after 30 days, credit will be issued toward future pruchases only and some additional restocking charges may be applied.
  • All credits from RMAs must be used within one calendar year of issue.

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Path Way® Model 4143 Automatic Fallback RS232 DB25 A/B Switch with Remote Access


  • PORT CONNECTORS: (3) DB25 female connectors labeled A, B, and COMMON. 
  • FRONT PANEL CONTROL: (1) Manual pushbutton allows local switching.
  • DISPLAY: (2) Front panel LEDs display switch position, mode and power status.
  • REMOTE CONTROL: Transition signals on pin 9 of the DB25 COMMON port will trigger a change of switch position.
  • POWER: UL approved 100VAC/240VAC 50 Hz/60Hz wall mount power module supplies 12VDC, 500 mA to the unit. Has 2-prong, US, non-polarized plug.
  • DIMENSIONS: Desktop configuration 8.1" W x 2.41" H x 7.30" D (20.8 x 6.2 x 18.6 cm) 
  • WEIGHT:  Approximately 1.9 lbs. (0.9 kg) 

Model 4143 Automatic Fallback RS232 DB25 A/B Switch w/Remote Access

DB25 AUTO FALLBACK APPLICATION: The application drawing illustrates a COMMON device or Network connected to the DB25 COMMON port with access to two other DB25 interface devices, connected to the DB25 A and B ports. respectively. Pin 9 of the DB25 COMMON port is used for Remote Control operation via transition signals.


  • The switch ports are transparent to data.
  • Pins 1-8, and 10-25 of the DB25 interface are switched via break-before-make electromechanical relays.
  • Pin 9 of the Common port is used for Remote Control and does not pass through the switch. 
  • The unit maintains last set position on power loss and continues to pass data.
  • Front panel pushbutton control.
  • Manual Mode is achieved by pressing the front panel pushbutton for 5 seconds or alternately pressing for 5 seconds to exit Manual Mode.
  • Automatic Fallback Mode is controlled by Pin 9 of the DB25 COMMON port. 
  • A transition from 5VDC to 0VDC on Pin 9 of the DB25 COMMON port triggers the unit to switch positions.
  • Custom length DB25 cables available for your switch installation. 

The PathWay® Model 4143 Automatic Fallback DB25 A/B Switch with Remote Access allows the user the capability of sharing a single DB25 interface device connected to the "COMMON" port among two other devices connected to the "A" and "B" ports with remote access functionality.  The Model 4143 is packaged in a slim desktop style enclosure.

The switch may be controlled locally by manually operating the front panel pushbutton, or remote access through Pin 9 of the DB25 COMMON port located on the rear of the unit. The front panel LED display indicates the switch position, switch mode, and power status.

Wide Range Power Option Available: (Cat No 517277) CE, RoHS, and UL listed table mount power module, 100VAC/240VAC, 50/60Hz for use in place of the standard power module that is included with the unit.  Has IEC 60320 C14 inlet. Ideal for international applications.

 For custom network switches call our friendly customer support staff at 401-943-1164, email eslab@electrostandards.com, or complete our online form.

 EElectro Standards can supply all of your Network Cable requirements. Click here to reach our Copper Cable Assemblies Webpage.

All ESL products are available for export. Electro Standards welcomes inquiries from International accounts: commutateur de réseau, conmutador de red, switch di rete, przelacznik sieciowy , switch de rede, nätverksswitch.

All data switch boxes, data communication products, and data acquisition products are subject to a one year warranty against manufacturing defects.  The limit of ESL liability is limited to the cost of the ESL product provided.

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