Modbus RTU .NET Expert

Hello, We have a device and related RTU document for accessing the registers using Modbus. We are doing this first time hence looking for someone who is familiar and can guide us. It should not take more than 1 hr for someone who understands it. We will show you everything using images/screenshots/TeamViewer. And then you will be awarded the work Easy Modbus RTU .NET application in C# or VB.NET. where my Autonics TM4-N2SB unit connect via RS485 and i can sent each ch1 - 4 and read each ch1-4. i want simple application where ( connect via RS485 selecting port and all.) WRITING / SETTING CHANNEL Ex. i want to set channel 1 temperature as 250 degree Celsius i will press button. it will sent. likewise other channel also set or single press it will set all 4 channel. READING like above writing / setting. i will press button it will show me / give channel 1 preset temperature. likewise other channel also i can read. Autonics has there own software called DAQMaster where i can connect and set temperature and read each channel preset value also. but i dont know about ModBus Communication Protocol and CRC. so need simple application. Autonics TM4-N2SB communication Manual is attached.