problem in mapping xml data with imported RFC parameters

I am currently working on a senario in which a flat file is generated by an RFID server and placed in FTP server.

The flat file is picked up from the FTP server using XI and the contents are mapped to the corresponding imported RFC parameters.

The content of the file which is in text format is successfully converted in XML at the XI side.

File contains records of 2 fields Functional location and RFID equipment number . In the R/3 side these fields

are used as Functional location and equipment number of PM module .

The structure of the FTP message is as follows

<ns:RFID_MSG_TYPE xmlns:ns="urn://sisl:rfiddemo">

<RecordSet>

<Row>

<FL1>"f1</FL1>

<FL2>01</FL2>

<FL3>01</FL3>

<RFID_NUM>I001"</RFID_NUM>

</Row>

</RecordSet>

</ns:RFID_MSG_TYPE>

After the mapping program which maps the above structure to the imported RFC is executed the following payload document is generated

<ns:ZRFID_EQUIP xmlns:ns="urn:sap-com:document:sap:rfc:functions">

<RECORDS>

<item>

<FLOC>f1-01-01</FLOC>

<RFID_NO>I001</RFID_NO>

</item>

</RECORDS>

</ns:ZRFID_EQUIP>

The size of FLOC is 30 of type string and RFID_NO is also a string with size 18.

When the data is brought in R/3 both the fields FLOC and RFID_NO gets mapped in FLOC which is of type char30.