“Safety automation that gets rid of hardwired stops, but the cable market accelerates anyway because now you need cables devoted to this new technology.”
Nabrotsky adds another reason for softwire’s growth is that the National Fire Protection Association (NFPA) revised its rules in 2002 to allow higher-voltage power, typically 30 A and 600 V, to be supplied via softwiring with factory-applied, molded connectors. Again, this design simplification reduces labor and potential errors, but it also fits with how cables and connectors have evolved in recent decades.
“Simple tool cords began to be used in the 1970s, and these branched into networking in the 1990s and softwired power in 2002,” says Nabrotzky. “Next, we’re seeing safety automation that gets rid of hardwired stops. This means you no longer need cables for that task, but the cable market accelerates anyway because you do need new cables devoted to the new safety automation.”
Nabrotzky adds that future developments also will include more data and power combined in the same system, especially when a Power over Ethernet (PoE) standard is completed. He also expects DeviceNet and AS-i to tie power and data onto the same cable.
Connector Methods for Networks
Most industrial networks use one or more of the following three connector technologies:
- Mini: These connectors are based on a 7/8-in wide barrel with a 16 pitch. They usually consist of two through seven-pin connectors.
- Euro or Micro (DC): These are based on M12 threads, and have a coupling unit that’s about 14 mm wide. They include two through six-pin connectors.
- 9DB: These include D-shell, subminiature connectors typically with nine pins.
Cable and Connector Glossary
The following terms are some the basic instruction included in Belden CDT’s Cable 101: The Basics of Wire & Cable.
- Attenuation: A measure of a cable’s loss of electrical energy; expressed in dB/unit length
- Breaking strength: The pulling force, in pounds, that will cause a conductor to fracture.
- Capacitance: A measure of insulation’s ability to store electrical energy; expressed in picofarads per foot.
- Dielectric constant: Electrical property that determines capacitance, propagation velocity, impedance, and insulation performance.
- Dielectric strength: Material’s ability to withstand voltage breakdown; expressed in volts (V) or kilovolts (KV).
- Flexibility: Ease with which a conductor can be bent.
- Flex life: Ability of the conductor to bend repeatedly without breaking.
- Insulation: Substances that electrically and physically separate conductors in a cable.
- Length of lay: The number of twists in a conductor.
- Propagation velocity: Transmission speed of an electrical signal through a length of cable; compared to light speed in a vacuum.
- Skin effect: As its frequency increases, the flow of electrons move to the surface or skin of the conductor.
- Working voltage: Maximum voltage allowable by UL to be applied to cable; expressed as AC Volts (V) or kilovolts (KV).
- Shielding: Contains electrical energy so signal on cable doesn’t radiate and interfere with other nearby signals.