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Catalog # 303090 - Model 4145 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: 303090
Model No: 4145
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, RS232 Serial
Auto Fallback:Carrier Detect, DCD, Port A
Pins Switched:1-8, 20
Remote Port:DB9
Local Control:Pushbutton


Shipping Terms

Shipments are made via UPS Ground, unless otherwise specified. Freight charges are prepaid and added to your invoice. We can estimate the freight costs for you.

We can ship freight collect on your account, just provide your UPS Account Number.

We can also ship via the carrier of your choice. Provide the details and your account number.

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 4145 Automatic Fallback and Recovery DB25 A/B Switch with Optional Remote Control

  • Fallback based on loss of carrier (DCD)

  • Network DCD "Watch Dog" switch keeps data flowing!


  • DATA 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 and power status.
  • REMOTE CONTROL OPTION: (1) DB9 Female connector on rear panel accepts ASCII RS232 Serial Data for Remote Control operation.
  • POWER: UL approved wall mount 100VAC / 240VAC, 50Hz / 60Hz power module supplies 12 VDC, 500 mA to the unit.
  • DIMENSIONS: Desktop configuration, 8.11"W x 2.37" H x 7.28' D (20.6 x 6.1 x 18.4 cm) 
  • WEIGHT: Approximately 1.8 lbs. (.09 kg) 

PathWay® Model 4145 Automatic Fallback Application:

  • RS232 Auto Fallback DB25 A/B Switch Application w/Optional Remote: Ideal for automatic fallback applications based on loss of carrier (DCD).

PathWay Model 4145 Automatic Fallback Application


  • Ideal for automatic fallback applications based on loss of carrier (DCD)
  • The switch ports are transparent to all data. 
  • Pins 1-8, 11, 14-21, and 24 of the DB25 interface are switched via break-before-make electromechanical relays.
  • When in Fallback Mode, Pin 8 (DCD) or port A with respect to Pin 7 (signal ground) is monitored for carrier presence.
  • The unit maintains last set position on power loss and continues to pass data.
  • Front panel pushbutton control.
  • Optional Remote RS232 ASCII commands that allow the user to, control switch position, lockout front panel operations, change switch mode, obtain switch status, as well as query firmware version number, query serial number and enable/disable autosend of switch positions.
  • Municipalities, schools, government: This product is on GSA Schedule! 
  • Fallback based on loss of carrier (DCD)

The PathWay® Model 4145 Automatic Fallback and Recovery DB25 A/B Switch with Optional RS232 Remote Control allows the user the capability of sharing a single port interface device connected to the "COMMON" port among two other devices connected to the "A" and "B" ports, with remote access functionality.  The Model 4145 is packaged in a slim desktop style enclosure.

The switch may be controlled locally by manually operating the front panel pushbutton, or remotely through the DB9 Female Serial Interface Remote port located on the rear panel of the unit. (If the Remote port has been ordered). The front panel LED display indicates the switch position, switch mode, and power status.

The unit monitors data activity on port "A" for carrier presence (DCD) signal on Primary line Port A. If the unit is in the A position and activity is lost, the unit automatically switches to the B position. When carrier is detected on Port A, the unit will automatically return to the A position.

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

This high-quality network switch is available to city, state, and federal government purchasers at a discounted price and favorable payment and shipping terms via GSA Schedule GS-35F-0286V. Click here for GSA terms.

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

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

All data switches, 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
*Prices online are subject to change and verification.

All ESL products are available for export.

Electro Standards welcomes International inquiries: commutateur de réseau, conmutador de red, switch di rete, przelacznik sieciowy, switch de rede, nätverksswitch,


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