Envoy Application Programming Manual

BISYNC Centralized Multipoint Supervisor Protocol
Envoy Application Programming Manual—427159-001
4-28
READ Procedure
Continuation READ (Line in READ State)
All READs following the initial one are continuation READs. A continuation READ
(Example 4-8) causes Envoy, on behalf of the application process, to send the proper
acknowledgment for the preceding message, read the next message, and return the
message to the buffer of the application process. The successful receipt of a message is
indicated by a condition code of CCE upon completion of the READ.
172 Reply not proper for protocol. The data
received while waiting for a response to the poll
sequence was not proper for the BISYNC pro-
tocol.
CONTROL
173 Transmission error. The message received was
in error and a NAK sequence has been sent the
number of times specified by the retry value.
CONTROL
176 Poll sequence ended with no responder. The
specified number of passes were made through
the poll list and no message was received. This
error may also indicate that an empty poll list
was specified.
CONTROL
177 Text overrun. The length of the message
received exceeds the length specified in the
read count parameter. The READ was
attempted the number of times specified by the
retry value.
CONTROL
178 No address list has been specified. CONTROL
Example 4-8. Continuation READ (Line in READ State)
Supervisor (Local) Tributary (Remote)
line state = READ
CALL READ(...)
| ACKn -->
| <-- message n
(READ completes)
error = 0
line state = READ
CALL READ(...)
| ACKn -->
| <-- EOT
(READ completes)
error = 163
line state = CONTROL
MCW.<8:15> contains the entry number for the station
Table 4-10. Initial READ File-System Errors (page 2 of 2)
Error Number Description Resultant Line State