Class COM_DEVICE

-- Current control parameters for this device

-- Handle to communications resource

-- Information about the device driver

-- Line driver status parameters

-- Current timeout properties for this device

-- Is the device open for reading and writing?

-- Close the device.

-- Open the device.

-- Configures the device according to the specifications in a_settings.

-- Configure the device using a_control_string, e.g. "9600,n,8,1"

-- Sets the timeouts parameters to those in a_timeouts

-- If the device is still open then close it

-- Read count bytes into the data buffer. Set last_read_count
-- to the number of bytes read. Set timed_out if less than count
-- bytes were read. See timeouts to determine when read will
-- be completed.

-- Write count bytes of data to the device. Set
-- last_write_count to the number of bytes written.