Every Transaction is independent of every other Transaction and can only be initiated by the Host computer.
A valid Response Packet must be received by the Host computer to complete a Transaction before the next Request Packet is sent.
If an error is encountered during a Transaction, the entire Transaction (i.e., Request Packet and Response Packet) must be repeated.
The Zebra printer does not provide for system time-outs and has no responsibility for insuring that its Response Packets are received by the Host computer.
The Host computer must provide time-outs for all of the Transactions and insure that communication continues.
If any part of a Transaction is lost or received incorrectly, it is the responsibility of the Host computer to retry the whole Transaction.