How does Modbus ASCII encode data for transmission over serial lines?
Answer
Using human-readable ASCII characters
Modbus ASCII mandates that data be transmitted using human-readable ASCII characters. This method offers the advantage of easier debugging using simple terminal viewing equipment, as the transmitted data can be directly read by a person. However, this readability comes at the cost of efficiency. Each byte of actual data requires two ASCII characters for representation, leading to higher overhead compared to the binary packing used in Modbus RTU. Furthermore, ASCII mode relies on specific start (colon) and end (carriage return/line feed) characters for synchronization, rather than just silent time gaps.
Related Questions
What company conceived the Modbus protocol, which was introduced in 1979?What specific error checking mechanism does Modbus RTU employ for transmission integrity?How does Modbus ASCII encode data for transmission over serial lines?What is the access characteristic for Modbus 'Coils' register type?What fundamental element did Modbus TCP/IP eliminate the need for regarding error checking in serial communication?Why is Modbus ASCII transmission inherently less efficient than Modbus RTU?What is the definition and access type for 'Input Registers' in the Modbus data structure?What attribute of Modbus is considered the single biggest factor explaining its continued relevance despite its age?What critical limitation exists in the original Modbus specification concerning data security?What synchronization mechanism does Modbus RTU rely upon for message boundary definition?What is the purpose of consulting a 'device profile document' in modern Modbus deployments?