bit storing as byte

AJITnayak:
I am trying to impilment modbus RTU with read coil register.

404 Error: Page Not Found - Jewell Instruments.

I have working code till receive data upto crc check & receive response from slave. My main problem is once data being received how can read coil register & pack data & send back for CRC check

I havent used the serial of arduino i have written in embedded c on atmega controller.

What do you find lacking in any of the existing libraries for Modbus RTU?