Envoy ACP/XF Application Programming Manual

System Procedure Call Specifics for EnvoyACP/XF
EnvoyACP/XF Application Programming Manual–132179
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READ[X] Procedure
addr^ab35,2 * [0] ]; ! Station AB35 entry
CALL DEFINELIST (fnum,station^list,entry^size,num^entries,
polling^count,polling^type);
Condition Codes
READ[X] Procedure
A call to the READ[X] procedure accepts one incoming frame and returns data and/or a
two-byte Message Control Word (MCW) to the specified application buffer. READ is
intended for use with 16-bit addresses, while READX is intended for use with 32-bit
extended addresses. Therefore, the data buffer for READX can be either the caller’s
stack segment or an extended data segment.
After opening a communications line, always have at least one incomplete READ[X]
call to make certain that if something unexpected comes down the line, you receive it.
For NRM configurations, READ initiates polling if there are currently no received
frames in the input queue associated with the particular line and no WRITE requests
pending for that line.
The form of the READ[X] procedure is:
filenum input
INT:value (Use with both READ and READX)
is the number returned by the OPEN call that opened the line. In a READ[X] call,
you supply this variable to EnvoyACP/XF.
buffer output
INT:ref:* (Use with READ)
STRING .EXT:ref:* (Use with READX)
is the name of the integer array within the application process where the incoming
data is to be placed.
Note. Even though EnvoyACP/XF allows you to specify an extended address field for all
protocols, be aware that the SDLC protocol standard does not support the extended address
field. See the IBM Synchronous Data Link Control General Information Manual.
= (CCE) indicates that the DEFINELIST procedure was executed successfully.
< (CCL) indicates that an error occurred (call FILEINFO).
CALL READ[X] ( filenum !i
, buffer !o
, read-count !i
,[count-read] !o
,[tag]); !i