Ricoh A250 Service Manual page 439

FAX COMMUNICATION FEATURES
Two-step Shift-down from the Sending Terminal
The diagram shows the protocol used by this model acting as the sending terminal.
If this machine has received four PPRs for one ECM block, it will request the
receiving terminal to accept a two-step shift-down in the next control channel.
A250
TX
33.6kbps
Fax data
33.6kbps Fax data
33.6kbps Fax data
33.6kbps Fax data
33.6kbps Fax data
Shiftdown M P h
28.8kbps Fax data
2-18
RX
P P R 1
2
P P R
P P R 3
P P R 4
M P h
M C F /
P P R
M C F
A891D533.WMF
SM