I want to connect all the burned instruments to a single line using HART communication; I wonder if that’s possible
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A fire has broken out at a location in the factory where cables pass through, and many of the instrument cables have been damaged. It will take 3 days to repair these cables, but only one day’s time has been allocated for this task. I’m wondering if it’s possible to connect all the damaged instruments to a single cable using HART communication; all the points that were damaged are those that use the HART protocol, and the cards used also support HART
The Hart protocol supports a bus architecture; up to 15 instruments per loop (addresses: 1–15)
Hart can carry a maximum of 16
Due to the quantity limits on Harts, it is recommended to use junction boxes on-site. First, lay the cables in the cable trays and connect them to the junction boxes. One day should be allocated for wiring the instruments
I can say with certainty that 90% of them won’t work! You’ll know if you try it. The Hart protocol supports serial bus communication. They can be connected in series on an RS485 network, with differentiation based on addresses. But have you seen current signals of 4-20mA being connected in series in a similar manner to RS485?
The instruments mentioned by the poster all support the Hart protocol, and the cards as well support this protocol; a single cable is used to connect 15 instruments in a bus-based configuration. Theoretically, it seems feasible, but in my experience, with cables that are too long (about 200 meters), it’s impossible to connect the field instrumentation devices to the DCS side using a 375 connection; either there is no connection at all or the connection is intermittent. Therefore, from a perspective of safety and reliability, it’s safer to use hardwired connections. http://bbs.hcbbs.com/thread-385585-1-3.html The second floor has covered everything quite thoroughly; these issues must be taken into consideration.
The Hart method is not feasible. Two terminal boxes are installed at both ends of the burned cable, which greatly reduces the workload involved in handling the cable.
HART communication is generally used for debugging, and it is rarely seen being used for process control. Estimation is quite challenging.
We usually use HART communication for debugging purposes; we have not used it for process control. If the original poster is successful, please share the experience with us.