Comparison of Network Communication Cables for Makers: Ethernet, Serial, and Fieldbus Options

Overview: why cable choice matters for makers

Selecting the right network communication cable affects signal integrity, latency, installation ease and long-term reliability of maker and education projects. This guide compares common cable types used by makers - twisted pair Ethernet (Cat5e/Cat6/Cat6a), shielded variants, USB/serial wiring, CAN/RS-485 fieldbus cabling, and fibre - explaining where each is appropriate for hobby, lab and small industrial applications in South Africa.

Key parameters to consider

• Bandwidth and data rate (e.g., 100 Mbps vs 10 Gbps)
• Cable impedance and pair symmetry (important for Ethernet)
• Shielding (UTP vs STP/FTP) for noisy environments
• Maximum segment length and repeaters/extenders required
• Mechanical flexibility for breadboard/prototyping vs permanent installs
• Local availability, lead times and typical brands stocked

Common cable types at a glance

For readers planning purchases, check local branch stock and pick-up options to avoid project delays. See our branches and trading hours for Samrand, Pretoria and Cape Town to plan collection and VAT invoicing.

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Standards, specs and selection criteria

When choosing a cable, review electrical specs and mechanical factors. Key electrical specs include characteristic impedance (typically 100 ohms for Ethernet), capacitance per metre, and insertion loss (attenuation). For many maker projects the following quick checks help:

• Match cable impedance to the interface (e.g., 100 ohm twisted pair for standard Ethernet)
• Choose shielded cable (STP/FTP) where motors or RF modules create interference
• Use twisted pair or differential signalling for longer runs (RS-485, CAN)
• Prefer stranded conductors for flexible jumper cables and solid conductors for fixed wall runs

Simple calculations and wiring examples

Attenuation and cable run checks: for Ethernet runs, keep passive segments under 100 m to avoid excessive attenuation. For RS-485, higher speeds reduce maximum run length; a practical engineering approach is to halve the length when doubling speed to estimate behaviour.

Ohm's law can help with power-over-cable considerations when running low-voltage supplies over the same cable:

Vdrop = I x R (where R = cable resistance per metre x length). For example, a 2 A device on a 10 m run with conductor resistance 0.02 ohm/m gives Vdrop = 2 x (0.02 x 10) = 0.4 V.

Wiring diagrams (ASCII) for common maker connections

Ethernet (T568B) pinout for RJ45 patch cables - useful when making custom patch leads:

Pin: 1 2 3 4 5 6 7 8
Colour: W-O O W-G B W-B G W-BR BR
(Use a proper crimper and continuity tester)

RS-485 two-wire differential pair typical connection:

Device A      Device B
+ (A)  ---------+  + (A)
- (B)  ---------+  - (B)
Terminate ends with 120 ohm resistor across A and B for bus stability.

Troubleshooting common cable problems

• No link LEDs on Ethernet: check RJ45 pin continuity and pair order with a tester
• Intermittent serial noise: replace with shielded twisted pair and ensure proper grounding
• High error rates on long links: shorten runs or add repeaters/extenders; consider fibre for immunity

For hands-on builders, Communica stocks test & measurement tools useful for diagnostics including cable testers, multimeters and oscilloscopes. Explore product breadth by brand in the shop by brand section or view all products to compare specific cable assemblies and adapters.

See brands we stock and browse all products to match cable specs and accessories. For company background and credibility when purchasing for education or projects, read about our history and capabilities.

Practical South Africa-focused buying tips

Stock and lead times can vary. For critical student labs or prototype deadlines, use branch pickup at Samrand or Pretoria to secure parts faster and get VAT invoices for procurement. Typical on-shelf brands useful to makers include maker-favourite modules and global cable/connector brands; check current availability online before planning complex installs.

Summary recommendation: For most maker projects with short runs, Cat5e stranded patch leads are economical and flexible. For higher speed or electrically noisy installations choose Cat6/Cat6a (shielded where needed). Use twisted pair differential cabling for RS-485/CAN, and consider fibre where distance or EMI makes copper impractical.

Sources

• Communica - About Us
• Communica Collections (Cables, Connectors, Test Equipment)
• Ethernet cable (overview) - Wikipedia
• RS-485 (serial differential signalling) - Wikipedia