What is the difference between active wiring and passive wiring?
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I want to know the difference between active wiring and passive wiring? This post was last edited by marry on 2009-3-26 13:44 ]
Could you please clarify, where are the active and passive connections? Where is it used?
Active wiring means that the meter itself has a separate power supply, and its signal is an active signal, so there is no need to provide additional power to the meter. Passive wiring means that the instrument must be powered by power wiring.
There is no difference for the signal line, but there is a difference for the instrument and the card. The active instrument is a four-wire system. In addition to the signal line, there is also a power line, and the corresponding card does not provide power. The passive one is a two-wire system, the instrument is not connected to a separate power supply, and the corresponding card has a power supply.
Haha. No factory can learn from the master* If people are different, they will learn from the master * There are a lot of unique terms... Passive wiring, and active wiring... are connected from the field instrument to the DCS or the display on the secondary instrument. If the primary instrument (field instrument) is a four-wire system, it has a separate power supply circuit. Passive wiring does not need to be accompanied by a power supply on the signal line... Other two-wire instruments require active wiring. Add a 24v power supply to the signal line for the instrument to use... It's a bit confusing. Let's take a look. Haha...
If the transmitter has power, signal 2 line, then this signal is an active signal； If the power supply and signal of the transmitter are on the same route, that is, a two-wire transmitter, this signal is a passive signal. In fact, the power signal is merged together. This post was last edited by zhaohh3211 on 2009-3-26 09:15 ]
Passive: A typical example is a pressure transmitter. The instrument itself has no power supply and needs to be provided by DCS. ； active: For example, a 4-wire (220V.AC Power, 4-20mA) electromagnetic flowmeter has a 24V.DC power supply inside the instrument itself and does not need to be provided by a DCS. ； E+H electromagnetic flowmeter (Promag 10P 220V.AC power supply): The description of the output current is: Active: 4...20 mA, RL < 700 Ω Explanation in wikipedia: Depending on the source of current for the loop, devices may be classified as active (supplying power) or passive (relying on loop power).