[This is preliminary documentation and subject to change.]
Once your application has opened and configured a connection to the remote control and specified the relevant key codes for the remote control, your application can begin to send command sequences that will perform specific VCR operations. Sending command sequences consists of separately sending one or more one-byte values that either modifies the remote control or causes the VCR to perform an operation. Before sending a command, your application should first determine that it previously opened a connection to a serial port and put the remote control in automatic mode. If either one of these conditions are not met, your application will not be able to send commands that operate the VCR. Next, your application should create a pointer to a buffer and fill that buffer with the one-byte value that your application requires sending. Finally, to send the command, your application should call the WriteFile function, part of the Microsoft® Win32® application programming interface (API), and pass the handle to the serial port to be written to along with the buffer containing the one-byte value.
When your application sends a start or stop recording command, your application only requires sending a single one-byte value. When your application requires tuning the VCR to a specific channel, your application must send two or more one-byte number values that represent the channel to tune. If the channel specified in the command line is a number less than ten, the first one-byte number value your application should send is the one that represents a zero.