Data Channel with Recovery for Errors in Messages Sent to an Associated Processor
Original Publication Date: 1987-Mar-01
Included in the Prior Art Database: 2005-Feb-02
When a channel sends a message to an associated processor, it puts a sequence number in one field of the message and sets a bit in another field to signal that the message is not a duplicate. The channel makes conventional checks for data transmission errors. If an error is detected, the channel resends the message with the same sequence number and with the bit set to identify a duplicate message. From the standpoint of the associated processor, the duplicate message bit means that a subsequent message with the same sequence number is invalid. The associated processor tests the duplicate bit in each message, and if the duplicate message bit is set it discards the message with the duplicate bit set.