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Figure 34 Storage Modbus Gateway
As shown in figure 34: ordinary Modbus TCP data flow direction
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1
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2
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3
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4
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. In other words, Modbus TCP instruction is first converted into
corresponding Modbus RTU instruction, and then the device responds Modbus
RTU instruction to Modbus gateway, which is then converted into Modbus TCP
again and sent to the monitoring host computer.
As we know, Modbus TCP is a network communication with a fast transmission
speed, which can be answered within 3ms, while Modbus RTU is RS485 with a
speed of only 9600bps. Generally, it takes at least 30ms to send and return an
instruction. Such a common non-storage Modbus gateway has a relatively long
query response time. In addition, if there are many upper computers to query data
