What is the actual transmission distance of a 4-20mA signal?
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Dear experts, the distance from my location to the PLC cabinet is over 1100 meters. The signals used are 4-20mA signals as well as digital signals. I’m using 2×1.5 mm diameter signal shielding cables for these signals, while 24VDC DC power is transmitted using 2×2.5 mm diameter shielding cables. I’ve read that this should work in theory; I was wondering if anyone has actual experience with this setup and could share some insights. Thank you all!
It’s too general; the distance is related to the load. Generally, the wire diameter needs to be increased when the distance exceeds 600 meters.
For such long distances, it is not recommended to use 4-20MA transmission even if the signal does not attenuate, unless in a few isolated monitoring points. The longer the distance, the more interference signals there are. Suggested communication.
500-600 meters? I haven’t tried it; I’m not a designer
This is related to the power of the card and the internal resistance of the instrument cable
Theoretically, a 2*1.5 cable can transmit signals for 1500 meters, with a safe distance of 1000 meters
For 1100m, it is recommended to install a dashboard on-site and run optical fibers back to the control room
It seems that the error in instrument transmission lines is minimal within 150 meters; the error increases as the distance increases. For distances of 1100 meters, it’s better to use network transmission, as the distances are too great
Thank you all for your support. I wonder if anyone has encountered situations involving distances over 1000 meters in their actual work?