Control cables and computer cables
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I just started working, and I’m a bit confused about cable selection in design firms. For the 4-20mA signals from transmitters, should control cables be used or computer cables? Should the solenoid valve signal and the on/off feedback signal on the valve be transmitted using a computer cable or a control cable? I’m completely confused; please ask an expert to explain it in detail!
Generally, computer cables are used for analog signals, while control cables are used for digital signals.
Do you all still remember that years ago, the safety barrier manual included a specific note indicating which models of instruments could be used together with this safety barrier for certification, as well as which types of safety barriers were compatible? Standards are important; anything else that is not based on standards is nonsense.
The regulatory standards have specific requirements; just purchase according to the design specifications. The actual difference is not significant; it’s even smaller when the cable isn’t long. Substitutes generally don’t have much of an impact.
It is recommended to consult GB/T9330.1~3-2008 and TICW/06-2009: 1. Control cables are non-intrinsic safety (normal type) and do not have screen separation. Used in non-explosion-proof and flameproof instruments. 2. Computer cables are divided into intrinsically safe cables and regular cables; there are master screens as well as master screens with sub-screens. Non-explosion-proof, flameproof, and intrinsically safe types are all useful. Note that there are also criteria such as fire resistance, flame-retardant ABC grades, PVC sheath, and cross-linked PVC sheath.
It seems simple, but it’s not easy to understand unless someone who knows explains it to you.
Follow the design specifications; other cables can also be used in non-special environments
Computer cables are specialized signal cables and low-voltage cables – generally made of twin or multi-twin twisted pairs, and their price is relatively high； Control cables: such as motor control wires used in the high-voltage electrical field, including unshielded and shielded types; those with shielding can also be used as instrument signal cables.