HP 262SA - Page 153

Data Communications
Table
7-7. Summary of Block Protocol Control Characters (Continued)
TEXT-IN TEXT-OUT
RECEIVED TRANSMITTED
RECEIVED TRANSMITTED
Sent by CPU as a response
Sent by terminal as a
to
an ACK received from
response to an ACK
terminal.
received from CPU.
CPU
has no moreTEXT to
Terminal has detected
CPU has decided to abort Term has no moreTEXT to
xmit to terminal.
data overrun. This is a terminal xmission.
send to CPU
or has just
permanent condition, as
received an ttRVI".
the size of the transmis-
sion exceeds
the size of the
terminal input buffer.
CPU requests terminal
Term requests CPU
send last TEXT response.
retransmit last response
to TEXT.
Terminal acknowledges
CPU acknowledges last
last text block and re- TEXT block & requests
quests the CPU to stop
term send ttEOT".
sending ( .).
Terminal tells CPU that
CPU tells term that last
last TEXT block was
TEXT that term sent was
received OK.
OK.
Term acknowledges last
CPU acknowledges last
TEXT block received is
TEXT b~
.k sent by term,
OK,
but now term has no
but tells term to wait be-
more buffers
& cannot ac-
cause CPU does not have
cept more TEXT.
any more buffs.
Term detected
error in last
CPU detected error in last
TEXT block CPU sent. In-
TEXT block
term sent. In-
valid VRC/BCC, etc. This
valid VRC/BCC, etc.
includes temporary buffer
overrun, where size of
transmission does not ex-
ceed size of terminal input
buffer.
CPU is temporarily
out of
Term is temporarily
out of
text.
The terminal must
data.
respond with a NAK.
7-41