RCA 70/700 Series Reference Manual page 107

Line Contro 1-
Command/Response
(Cont'd)
Data Transfer
Initial Conditions
Good
Message
Bad
Message
Good
Message
70/725 Data Gathering
System Buffer
Command/Response Exchange, CCM Validation
CCM
CCM
Recognizes
Generates
Buffer Action
ETX
ACKC
Transmits ACK (Tone)
Responds to SEL with END
Parity error NAKC
Inhibits Ready Awaits end
or End and (not req'd if
of carrier Transmits NAK
Error End and Error)
(Tone) Responds to SEL
with End and Error
Command/Response Exchange, Program Validation
CCM
CCM
Program
Recognizes Generates Generates
Buffer Action
ETX
TERC
-
- -
Responds with END
Write Control
followed by
Sends ACK (Tone)
ACKC or Write
Responds with END
Command fol-
lowedby ACK
ETX or End TERC
- - -
Responds with END
and Error
(Not req'd Write Control
(EER)
if EER) followed by
Sends NAK (Tone)
NAKC or Write
Responds with EER
Command fol-
lowed by NAK
(Not req'd if
EER)
• Whenever the buffer receives a SEL from the CCM, it responds with
BOP, regardless of command status or line condition. In the absence of a
command, this unit remains in the condition in which it is placed upon
termination (END) of the previous command.
It
is then conditioned to receive
a new command.
Whenever a signal appears on the Reset lead from the CCM, the buffer
is restored to its quiescent condition, the command which was present, if
any, is dropped, and Idle current is removed from the lineo This unit
responds to a subsequent SEL with BOP, only, until another command is
received.
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