Programmable slave I/O unit with Modbus protocol
Modbus is very wide known protocol in the industrial manufacturing and environment monitoring fields. It is suit master-slave or query-response distributed I/O applications. The unit is pre-installed a Modbus firmware. Therefore PC, HMI or PLC can use Modbus/TCP and Modbus/RTU protocol to communicate with I/O modules in the unit via the RS-232/485 or Ethernet interface.
Besides the slave I/O functionality, it is also a c language based programmable controller that equipped a DOS-like OS (MiniOS7). Users can use C compilers that can create 16 bit executable file (*.exe) to develop a program then download it to the controller. That let the controller work stand alone. There are two free charge version compilers (Turbo C 2.0 and Turbo C++ 1.01), we suggest users to use the Turbo C++ 1.01.
Using the software development toolkits that we provide can customize the firmware. The SDK provides rich functions for Modbus communication, such as Modbus/TCP master/slave, Modbus/RTU master/salve, Modbus/ASCII master, etc.
Note1: RS-232: RXD, TXD, GND
Signal lines are RXD, TXD and GND
Program download port
Note2: RS-485: Data+, Data-; Self-tuner inside
Note3: RS RS-232: RXD, TXD, CTS, RTS, GND
or RS-485: Data+, Data-; Self-tuner inside
Note4: RS-232: RXD, TXD, CTS, RTS, DSR, DTR, DCD, RI, GND