User`s guide

58 DC 900-1340I
BSC Programmer’s Guide
specify the CU. If the LSB of the field is not set to ‘1,’ the overall link statistics are not
cleared. Use CU number 32 to clear statistics for all control units.
An unsuccessful Clear Statistics command can return the following error code in the
dlRead pOptArgs.iICPStatus field (see Appendix D for error handling):
DLI_ICP_ERR_BAD_MODE
The function request is not available for the requested
access mode.
3.4.1.3 Set ICP Message Buffer Size Command
The ICP message buffer size applies to all links on the ICP. The DLI sets the ICP mes-
sage buffer size as part of the configuration process during the
dlOpen command. The
default ICP message buffer size of 1024 is used in the following situations:
• If the buffer size is not changed after the very first dlOpen is issued, immediately
after the BSC 3270 software is downloaded. (The
dlOpen function uses the value
specified in the
msgBlkSize parameter value, page 190.)
• If you specify an invalid buffer size for the Set ICP Message Buffer Size command
If your application must set the ICP message buffer size itself (see the caution previously
mentioned in Section 3.1.4), it must set the
cfgLink and enable DLI configuration
parameters to “no” and perform the following procedure:
First, download the BSC 3270 software and send a dlOpen request for one link on the
BSC 3270 ICP. Second, send a
dlWrite function with the pOptArgs.usProtCommand field
set to
DLI_PROT_SET_BUF_SIZE. Set the iBufLen parameter to 2, and set the write buffer to
the maximum data size (in bytes) for any single transfer to or from the BSC 3270 ICP.
The valid range is 256 to 8192 bytes and must be less than or equal to the
maxBufSize
parameter in the TSI configuration file (the default value is 1024).
An unsuccessful Set ICP Message Buffer Size command can return one of the following
error codes in the
dlRead pOptArgs.iICPStatus field (see Appendix D for error handling):