Seeking help with issues related to Emerson Deltav data types
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Dear all**, we have a project that involves on-site PLC control cabinets; these cabinets use Siemens S7-200 Smart PLCs. Currently, they communicate with the client’s Emerson DCS system via Modbus-RTU. Communication is possible now, but the data transmitted appears to be garbled. In my PLC, the data is in 32-bit real format; for example, vd0 represents the temperature of the heat exchanger, and the actual value measured is 27.5 degrees Celsius. However, on Emerson’s end, the corresponding value is in the tens of thousands. I suspect that this issue is caused by different definitions of the data types, as Siemens stores 32-bit data with the lower bytes first and the higher bytes later. How should this be handled? Also, some of my values are negative; it’s probably not possible to directly swap the byte positions. How should I handle this?
Emerson’s system addresses all start with 40001; 40001 corresponds to 1. You just need to provide the address, baud rate, and other basic parameters, and communication can be configured