receive ready (HDLC) (RR)

Receive Ready (RR) is a control field in the HDLC protocol that indicates that a successful data transmission has taken place and that further data can be sent. With Receive Ready the last N frames are positively acknowledged. Since counting is done according to modulo 8, a maximum of 7 frames can be acknowledged at the same time. If a Receive Ready is received, then it indicates that the previously received frames were received without errors. The RR command is also used to query the status of the link layer.

Receive Ready is also transmitted from the receiving data station to the sending data station after a congestion resolution and indicates that the previous congestion situation indicated by Receive not Ready( RNR) has been cleared.