User`s guide

2: DDCMP DLI Functions
DC 900-1343D 51
defines the type of circuit exception received as shown in Table 2–13. Section 2.6.2.2
through Section 2.6.2.10 give details.
Circuit exceptions are messages generated by the ICP in response to unexpected proto-
col events. For circuit exceptions, the
pOptArgs.iProtModifier field values are greater
than 128 (decimal) to differentiate them from responses to client commands.
Odd-numbered circuit exceptions are non-fatal; that is, they do not automatically cause
the ICP to shut down DDCMP operations on the line. Even-numbered circuit excep-
tions are fatal; if any of these occur, DDCMP protocol on the specific line is halted,
requiring a Start Link command from the client before the line is restarted. See
Table 2–13 for the possible circuit exceptions.
2.6.2.1 Retry Limit Exceeded [129]
This exception is generated when the DDCMP retry limit has been exceeded.
Table 2–13: Circuit Exceptions:
pOptArgs.iProtModifier Field Values
Type of Received Data (Circuit Exception)
Value of Field
pOptArgs.
iProtModifier Reference Section
Retry Limit Exceeded 129 Section 2.6.2.1
Receiving Computer not Responding 131 Section 2.6.2.2
Receive Message Lost due to Buffer Unavailability 133 Section 2.6.2.3
Carrier Restored 134 Section 2.6.2.4
Disconnect (No DCD) 135 Section 2.6.2.5
DDCMP Start Received in RUN State 136 Section 2.6.2.6
Received Message Too Large 138 Section 2.6.2.7
DDCMP Maintenance Message Received 140 Section 2.6.2.8
Control Message Received in Maintenance Mode 200 Section 2.6.2.9
Data Message Received in Maintenance Mode 201 Section 2.6.2.10