AI828 226 Comm protocol description 072023 EN

Optimus Drive V9.X and above single-loop measurement and control instruments can support two communication protocols, AIBUS and MODBUS . Among them, AIBUS can realize comprehensive functions with simple instructions. Its characteristic is to write parameters At the same time, the reading function can also be completed, so the cycle time of reading will not be destroyed when writing parameters, and it is allowed to connect up to 80 instruments on one RS485 communication interface . The general-purpose MODBUS protocol has wider compatibility. The MODBUS protocol read command of V9.X or above can read up to 20 characters of data at a time, and its communication efficiency is greatly improved compared with the previous version of our company. The average time for the host computer to access a V9.X version of the V9.X version of the new generation of AI series meters is only 20About mS , when the data transmission time is not considered, the maximum delay time of the instrument after receiving the command from the host computer is only 10mS , and the average delay time is only 2~3mS , which is much faster than the previous version of the company, and can easily build a large-scale process control system. All V9.X versions of the new generation of AI instruments allow the host computer to write more than 2 billion times, ensuring that the internal memory of the instrument will not be damaged due to frequent writing by the host computer , and the host computer can be used to form a complex adjustment system for the instrument. AI series instruments can use PC , touch screen and PLC as the upper computer, and various configuration software resources are abundant in the market. The upper computer software based on PC widely adopts WINDOWS as the operating environment, which is not only intuitive and convenient to operate, but also powerful. The application of the latest industrial flat panel touch screen brings easy-to-use, rich-featured and cheap-priced options to industrial automation . This makes the price of the measurement and control system using the instrument + host computer structure much lower than the traditional DCS system,Its distributed structure also has high reliability . Except for some newly launched models, the V9.XX version communication protocol is fully compatible with the company's V8.XX communication protocol while improving performance and functions. The customer's original host computer software can be used directly without modification. Compared with the previous V9.0X version, the latest V9.1 version adds functions such as even parity mode, S6/S7 communication module address compatibility mode, and parameter writing restrictions. The parameter writing restriction function allows specific or all instrument parameters to be modified only when Loc is set to a specific value, which can reduce the situation where the instrument works abnormally due to communication software programming errors. The new communication protocol also supports the use of EP parameters to customize the parameters that allow continuous address reading and writing, which allows users to arbitrarily select up to 8 commonly used parameters to read in batches, thus greatly improving the operational flexibility.11. Interface specificationsAI series instruments use asynchronous serial communication interface, and the interface level complies with the provisions of RS232C or RS485 standard. The data format is 1 start bit, 8 data bits, no parity bit or even parity bit , 1 or 2 stop bits. The baud rate of communication transmission data can be adjusted to 48 00~ 288 00 bps , usually 9600 bps , if you need a faster refresh rate, you can also try to use 19200 or 28800 bps , when the communication distance is very long or the communication is unreliable and often interrupted, Optional 4800 bps . The communication distance of the RS485 communication interface is more than 1KM (some practical applications have reached 3-4KM ), and only two wires are needed to enable multiple AI instruments to communicate with the computer. Ordinary computers can use RS232/RS485 or USB/RS485 communication interface converters to convert the RS232