I'm new to HART and have skimmed the spec but I have a couple of question with respect to HART and its usage maybe someone out there can help me with.1) What is the typical (average) aount of data transfered by most applications, I'm assuming the master side is typically minimal while the slave side may be larger. I realize the max frame size is 256 bytes, is this typically filled or is this an unused "high-end?"
2) It seems as though retransmission typically occurs at the application layer rather than at the data-link layer. Is there ANY inherent retry mechanism for handling errors at the Data Link or is it only up to the applicaiton layer to provide this capability?
3) Are there any methods in place for a slave device to notify the master if the response time for a given request is going to exceed the "slave-timeout" time?
Thanks for your help.
-Mo