Software Reference Manual - NetEx

mod
BUF
BUFLEN
BFUBIT
BDTMOD
This parameter is the name of the block module.
This parameter defines the start of the block. For a receiving block module, the block information
will start at the beginning of the BUF array. For a sending block module, the block to be sent over
NETEX should be placed starting at the beginning of the BUF array.
This parameter specifies the length of the block in bytes. When the block module is called for the
first time, BUFLEN will have the maximum logical block length permissible with the user’s BLOCK
parameter. If the block module dislikes this value it can change the value of BUFLEN (and hence the
BFX buffer size) before returning to the control module. On subsequent calls, the receiving block
module will obtain the physical block length in this parameter; sending block modules should specify
the length of the outgoing block with this variable.
This parameter is the NETEX unused bit count. This value is principally used for sending or receiving
precise amounts of file information to systems whose word sizes are not a multiple of eight bits.
If the block module is a sending block module, then this value will be zero when the module is called.
If it wants to use the unused bit count facility, then it should place a nonzero value in the field.
NETEX will perform algebra on the datamode and total number of useful bits sent and will provide a
resultant length and unused bit count to be delivered to the receiving block module.
The receiving block module will have this value set on entry. It may use this field or ignore it.
This parameter is the DATAMODE field that is used to support the optional code conversion and assembly/disassembly
features of NETEX. Each time a transmitting block module is called, the
BDTMOD field will contain the DATAMODE that was negotiated at connection time based on the
system types and the MODE= parameters specified by both BFX implementations. The block module
may leave this value unchanged, or it may supply a DATAMODE in this field that will be used to
transfer the data buffer supplied by this call.
A receiving block module will have this value set to the incoming DATAMODE of the block that is
delivered to the block module.
BUFLEV
This parameter is the same as the BUFLEV parameter for record modules.
MSG
This parameter specifies an area that allows alphabetic information to be returned to the calling control
module. If the block module wants to return a message, it should place a string of EBCDIC character
information in this parameter. The maximum length of the message is 128 bytes. Unlike the record
module, this message will only be logged locally; messages sent between BFX programs must
be accommodated in the protocol implemented by the block modules.
MSGLEN
MSGLEV
This parameter indicates the length of the message returned by the block module. The length passed
to the block module is zero; if a zero MSGLEN is returned, it is assumed that no message is present.
Page 72 Appendix A: User Modules MAN-REF-H211-05