NET/MASTER Network Control Language (NCL) Reference Manual

CNMREAD
Verbs
3–28 106126 Tandem Computers Incorporated
CNMREAD The CNMREAD verb requests that the next communications network management
(CNM) record be made available to an NCL process. This verb allows you to read any
record that was solicited by, or was the response to, a CNM request.
Using this verb requires an understanding of IBM System Network Architecture
(SNA) networks.
CNMREAD [ ARGS [ RANGE=( start , end ) ] [ SEGMENT= n ] |
VARS={ input-vars-list | variable * }
[ RANGE=( start , end ) ] [ SEGMENT= n ] |
SET ]
[ TYPE={ SEG | VECTOR | BOTH | RESP } ]
[ WAIT={ NO | YES | nnnn } ]
When control is returned to the NCL procedure after a CNMREAD verb, the
&SYS.RETCODE system variable is set to one of the following values:
Return
Code Meaning
0 For a CNMREAD request other than TYPE=RESP, return code specifies that data has
arrived and is now placed in the variables as described for the CNMREAD verb.
4 Specifies that no data is outstanding. This return code can be expected if:
All reply data solicited using CNMSEND has been processed by previous CNMREAD
verbs.
No reply data was returned after a CNMSEND and a previous CNMREAD
TYPE=RESP has been issued.
No CNMSEND has been issued that specified that the results be returned to the
soliciting user, or no CNMSEND has been issued since the last CNMCLEAR verb.
8 Specifies that some error, such as a negative response, has been encountered. The
&SYSMSG variable is set; it contains text explaining the actual error. An implicit clear is
performed when the CNMREAD completes, obviating the need for an explicit CNMCLEAR.
12 Specifies that the time interval specified (by the WAIT=nnnn operand) expired before any
data satisfying the particular request arrived.
If multiple CNMSEND requests are performed before issuing a CNMREAD verb, each
CNMREAD request for data is satisfied by a request unit (RU) until all RUs from all
requests have been processed. All RUs are presented, in the order of their arrival, by
the first CNMREAD request, before any are returned for the next request. After all
RUs from all requests have been processed in this manner, a subsequent CNMREAD
completes with the &SYS.RETCODE system variable set to 4.
Note RU is IBM SNA terminology for a request or response unit. For the CNMREAD verb it is a response unit.
While one or more RUs related to a particular request are still available (that is, they
have not yet been processed by a CNMREAD request), a CNMREAD TYPE=RESP
always returns the response information for that request, even when subsequent