I have an application that has strict timing.
Inter-character delay must be no more than is 0.15s
The messages themselves are quite small. 10 - 50 chars
I don't understand what ReadTotalTimeoutMultiplier and ReadTotalTimeoutConstant actually mean in practice.
The math in this example doesn't work? http://www.lookrs232.com/com%5Fport%5Fprogramming/api%5Fcommtimeouts.htm
ReadIntervalTimeout = max time between two bytes ReadTotalTimeoutConstant = max time for a multi-byte read to complete ReadTotalTimeoutMultiplier = extra time allowed for each byte in a multi-byte read
Since you specified a strict limit on the inter-character delay, you'll want to only set ReadIntervalTimeout. Odd btw, the usual limit is a time-out on a message.