I've attached a new build of the code. It should resolve issues with serial RTU related to corrupted packets resulting in error 56. It also includes a more flexible timing value for RTU.
The serial code now works in such a way that even if it guesses wrong about packet size (based on RTU 3.5 char silence times), it will re-use the old data. That is, lets say the driver tells us we've had 64 bytes on the bus for more than 3.5 char times--this means we should attempt to process the packet. If CRC fails, we put that data in a buffer and listen again. This time we have 34 bytes on the bus. Once we actually perform the read, we'll have two arrays--data1[64+34] and data2[34]. If neither data1 nor data2 is valid and timeout has not elapsed, we listen some more...lets say we get data3[21], and this is the actual end of the packet. The processor looks at data1[64+34+21], sees that this is actually a complete packet (CRC=0) and passes this to the rest of the system. In this way we can still ignore noise or invalid packets and we have a bit more leeway on how well the serial driver handles the background transfer.
xtabi2
While fixing the above issues I think we should be in a state where you don't need the ability to change how long the code waits, but I added it in anyway. New behavior is to take the normal 3.5 char times, multiply by a factor (defaults to 1) and use that. While buffer size=0, it will poll at a rate of 6 or more ms, depending on baud rate. (For example 3.5 char times at 9600 baud is 4 ms, so the code polls at 6 ms until it sees any data on the line, and then will wait at least an additional 4 ms for silence on the line). You can set this factor. However, I compromised and did not expose this on the main API constructor functions. While I was writing the code I realized this was RTU-only, while the serial master/slave functions can work with both ASCII and RTU. Rather than including something that most users won't need to touch, I decided to simply put it inside of the constructor. Then, for people like yourself who need this feature, you can make a copy of the constructor for your own use and expose the properties you need. I've included an example for the master side, which defaults to dividing the time in 2.
joz
Please try this version of the code. Let me know if it fixes your issues.
