资 源 简 介
ModbusMaster is a class written in and for the Processing environment that enables you to communicate directly with a modbus RTU slave on any hardware serial port. Communication can take place simultaneously on multiple ports. All the communication is taken care of in the class and hides everything from the user.
Functions 1, 2, 3, 4, 15 & 16 are supported with broadcast functionality on function 15 and 16.
Communication is non blocking and you are able stop and start request packets easily.
Testing was done on a Lenovo X220 laptop with an FTDI (US232R-100-BST) USB to RS232 converter communicating with a GM7U LS Industrial PLC. The Duemilanove was also tested directly.
It must be noted in order to overcome the inter-character time out and the delays prevalent in the Processing/Java environment when using the serial library (RXTX-lib) the inter-character time out has been increased to 30ms diverging from the modbus standard. If needed the packet ra