Custom DB9 to RJ45 Cable
- DB9 male or female to 8P8C plug or jack
- Separate console, RS232, RS485, RS422, CAN, and adapter groups
- Rollover, straight, crossed, 2-wire, 4-wire, or custom routing by drawing
- Project-defined pairs, shield, termination, labels, and length
- Point-to-point and polarity verification to the approved specification
Custom DB9 to RJ45 Cables for Console and Industrial Serial Interfaces
A DB9-to-RJ45 cable can connect a D-sub serial interface to an 8P8C console or field interface, but it is not automatically Ethernet, and no universal DB9-to-8P8C pinout exists. Console, RS232, RS485, RS422, and CAN builds use different electrical definitions, pair allocations, and mappings.
BespokeCable produces the twelve cable and adapter cards represented on this page. Each build follows the target equipment documentation; a passive cable cannot translate RS232 into RS485, CAN, or Ethernet.
For a 25-position equipment port, see the DB25-to-RJ45 family; its passive wiring also requires an equipment-specific map.
DB9 to RJ45 Cable Specifications
| Parameter | Available Choices | Confirmation Needed |
| Interface | Console, RS232, RS485, RS422, CAN, proprietary | Electrical standard and device models |
| Ends | DB9 male/female; 8P8C plug/jack | Gender, orientation, retention |
| Wiring | Rollover, straight, crossed, 2-/4-wire, custom | Full pin map and polarity |
| Components | None by default; project-defined parts | Value, location, rating, schematic |
| Cable | Project-defined conductor/pair/shield | Length, route, ground plan, environment |
| Verification | Continuity/polarity to approved drawing | Functional-test scope if required |
Click here to learn more about what a DB9-to-RJ45 cable is.
1# Console Cables
P/N: BC-CBD016-MC
Male DB9 console cable for a documented 8P8C console mapping; identify the equipment family and rollover/straight arrangement.
P/N: BC-CBD016-FC
Female DB9 console build for the approved device map. “Cisco-style” must be tied to a documented product family.
2# RS232 Serial Bridge Cables
P/N: BC-CBD016-M-RS232
Male DB9 passive RS232 cable with equipment-defined TX/RX, ground, and optional handshake routing.
P/N: BC-CBD016-F-RS232
Female DB9 RS232-to-8P8C assembly; specify DTE/DCE roles and the actual crossover rather than relying on gender.
3# RS485 Cables
P/N: BC-CBD016-M-RS485
Male DB9 RS485 assembly with project-defined two-wire or four-wire pairs, polarity, reference, shield, and termination.
P/N: BC-CBD016-F-RS485
Female DB9 RS485 build for a verified device mapping; termination is included only when the bus design specifies it.
4# RS422 Cables
P/N: BC-CBD016-M-RS422
Male DB9 RS422 cable with separate transmit and receive pairs, polarity, reference, and shield defined by the equipment.
P/N: BC-CBD016-F-RS422
Female DB9 RS422 assembly with transmit/receive pair polarity, reference, shield, and any receive termination controlled by the drawing.
5# CAN Cables
P/N: BC-CBD016-M-CAN
Male DB9 CAN assembly with CAN_H/CAN_L pair, reference, optional power, shield, and termination defined by the network design.
P/N: BC-CBD016-F-CAN
Female DB9 CAN build for a documented CAN_H/CAN_L map, with reference, optional power, shield, and termination specified by the network design.
6# Inline Adaptersr
P/N: BC-CBD016-MA
Male DB9 to 8P8C jack adapter for a separately verified patch cord and passive device-specific map.
P/N: BC-CBD016-FA
Female DB9 inline adapter; label it with a serial number and document the patch-cord conductor order to prevent LAN misconnection.
Distinguish a Serial Modular Port From Ethernet
An RJ45-style 8P8C connector can carry a console or equipment-specific serial interface. Its shape does not make the connection Ethernet. These passive DB9-to-RJ45 assemblies route defined signals and do not perform serial-to-network conversion.
Confirm the function of both ports before mating them, especially around network switches and PoE equipment. A console cable approved for one device is not automatically suitable for another device’s identical-looking socket. The equipment model and interface specification are useful starting points.
Select RS232 Wiring by Port Role
For an RS-232 or console connection, identify the transmit, receive, and ground paths together with any handshaking signals. Port role and equipment-specific mapping determine whether you need a crossover or another arrangement. “Rollover” should describe a verified wiring pattern, not substitute for a complete connection table.
Specify the exact equipment ends and modular numbering view. A DB9 male or female option only changes what mates mechanically unless the wiring is also defined. This prevents connector gender from becoming an unreliable proxy for electrical compatibility.
Define Pairs and Bus Requirements for Differential Interfaces
RS-422, RS-485, and CAN configurations require interface-specific signal assignments. Pair identity, polarity, reference connections, and the system’s termination arrangement matter. A passive cable cannot convert one interface into another, even when the connector combination is the same.
Use the equipment documents and network design to define the harness. Specify whether any termination component belongs in the cable or elsewhere; do not assume it is included. Clearly mark each protocol-specific assembly so visually similar leads remain distinguishable during installation and service.
Include Every Adapter and Patch Lead in the Definition
The range includes finished cables and inline adapters. With an adapter, the separate modular lead becomes part of the electrical path and may change the end-to-end contact order. Include it in the approved configuration and replacement instructions.
Review the physical installation too. A rigid adapter can project from a port, while a cable requires routing and support. For cabinet or field applications, describe the length, environment, and shield-bonding plan so the mechanical format and conductor construction can be evaluated together.
Yes. Use separate customer part numbers and revisions for console, RS232, RS485, RS422, and CAN builds, even when the housings look identical.
Yes, but the approved patch-cord type and conductor order should remain on the drawing and packaging instructions.
They can if the purchase order defines individual bag labels, quantities, color coding, carton segregation, and inspection rules.
Related Products
Qualifying Several DB9-to-RJ45 Variants for One Equipment Program
Keep interface families separate at the planning stage
Build a variant list that identifies the equipment pair, interface, and wiring revision for each assembly. Do not group RS-232 console, RS-485, and CAN versions under one generic cable description just because their external connectors match.
Record the equipment documentation used for each map. When one model changes, this lets you review the affected variant without reopening every cable in the program.
Test a representative installation of each map
Verify the complete contact path before the functional test. Include the intended patch lead, adapter, and any termination specified by the system design. Then exercise the actual application with its normal settings and connected equipment.
A successful test of one protocol version does not qualify another. For networked differential interfaces, the installed topology and other nodes can affect the result, so a two-device bench arrangement may not represent the intended deployment.
Control the handoff to installation and purchasing
Give each accepted variant a clear part identity and equipment-end description. Define how mixed orders will be separated and how replacement staff will recognize the correct version. This reduces dependence on plug appearance or memory.
If equipment hardware or firmware changes, review the interface definition and previous test scope before assuming the cable remains approved. Where nothing electrical changes, that review can be brief; where the map or required behavior changes, revise and requalify the affected assembly.
