Sending with RDW and Receiving with RDW

When the Send file is in variable-length record format, you can retain the record descriptor word (RDW) when you carry out binary transfer of the file.

In addition, when the Send file from which you create the Receive file is in variable-length record format, you can retain the same format as the Send file.

Sending with RDW

The Sending with RDW function is available for transfer of variable-length format files. When you send files in variable-length format via binary transfer, you can use the function to add the record length information, called a record descriptor word (RDW), to the transferred data.

The Sending with RDW is available only when 'B' (BINARY) is specified for the Transfer Type (TRANSTYPE) in the Send Management Information. Also, the Send file must be in variable-length record format.

To use the Sending with RDW, specify 'Y' (Yes) for the Sending with RDW in the Send Management Information.

Note

  • An added record descriptor word (RDW) is 4 bytes long per record. The transfer data size includes the length of the record descriptor word (RDW).

  • Since HULFT adds a 4-byte record descriptor word (RDW) to each record to be transferred, the maximum length of a record will be 32752 bytes, as the below calculation shows. Therefore, the Sending with RDW is not available for files whose record length is 32753 bytes or more.

    a-b

    Table 3.23 Assignment Value in Calculation of Maximum Length of Single Record for Sending with RDW

     

    Description

    Value

    a

    Maximum record length of variable-length format file

    32756 bytes

    b

    RDW length

    4 bytes

Receiving with RDW

The Receiving with RDW function is available for receiving variable-length format files. Using the Receiving with RDW to receive files sent via binary transfer allows HULFT to read the record length information from the record descriptor word (RDW), which is added to the transferred data. Then, HULFT writes the data to the Receive file, based on the obtained record length.

The Receiving with RDW is available only when 'V' (Var) is specified for the Record Format (RECFM) in the Receive Management Information.

To use the Receiving with RDW, specify 'Y' (Yes) for the Receiving with RDW in the Receive Management Information.

Note

  • A record descriptor word (RDW) is 4 bytes long per record. The transfer data size includes the length of the record descriptor word (RDW).

  • An error occurs when records to be received exceed the record length of the Receive file.

  • Do not specify 'F' (Fix) for the Record Format (RECFM) in the Receive Management Information.

    For binary transfer in which data is received as fixed-length format files, if there is not sufficient data to fill to the last record, the record will be padded with NULL data. In this case, the receiving data differs from the sending data, and the Receiving with RDW cannot restore the receiving data.

  • If transferred data does not include a record descriptor word (RDW), the Receiving with RDW function is unavailable.