Operational Overview


At the heart of the DMX range are the converters; programmes which transform information to and from the specialised EDI syntax. DMXCONST will convert from application created intermediary files to files containing EDI interchanges. DMXTRANS will convert from files containing EDI interchanges to files for import to an application. 

Session Logging

DMXERRAN is used to translate logged information on partners and messages processed, files used and moved, profiles invoked, physical positions of messages and interchanges in files, data values nominated for logging, and detailed information about any errors detected into readable form. 

Table Maintenance

The creation and maintenance of tables, the format definition files govern how the converters manipulate information. DMXTLIST will display the structure and contents of a table in a form ideal for overview; DMXTDUMP will produce a comprehensive plain text file which completely defines the table. This text file can then be edited by the user 

Control Files

These are the text files which define the operational environment for the converters during a session. At their most basic they merely specify which input and output files are to be used, and which table should be read to govern the session. Most control files use little more than this plus a few specifications for file formats. You can specify where you want processed files moved to based on the results of the conversion, semaphore files for multitasking environments, code and character conversion definition files, a profile for data-driven context changes, constant data to be used during the session, and a number of other more exotic options


A profile is a potentially a complete specification for your EDI processing requirements for either construction or translation. You can relate any combination of trading partner and/or message type to the control file to be used for processing that combination. Since the control file specifies the session completely this gives you great flexibility. The control file information can be included directly into the profile if required. When running under a profile the converters match every partner and message type encountered in their input data against those specified in the profile. If a match is found then the existing control file information will be modified by the control file information specified for that match in the profile. This can include changing output files, tables and processing options.

This is easier in practice than it sounds, since the majority of your EDI processing will not require special context changes. Profiles always contain a default specification which is obeyed unless some more specific match can be found, and your profile normally only has to specify exceptions to the default processing.

A DMX converter is always supplied with the DMXPCOMP utility, which can convert plain text profile descriptions into the binary form required by the converters and will provide validation of the profile and identification of any potential problems involved in its use.


The majority of users do not have special requirements for an EDI converter above the functionality described so far. Occasionally the need does occur for special processing and in the past this normally required bespoke programs to massage the incoming or outgoing converter information. The DMX converters contain a script interpreter which can be invoked at most significant points in the conversion process to perform special processing (including links to external programs). The script language is specially designed for EDI processing, and plain text scripts in this language can be compiled into a table by use of the DMXSCOMP utility.

Use of such scripts is normally more advanced than the general user requires and the facility is intended for use by DMX vendors to customise the converters if required. One of the script language commands can however be used to implement code conversion and the DMXSCOMP script compiler is therefore supplied as part of a DMX converter purchase, since this is (regrettably) something which users do ask for.

Character Conversion

One aspect of EDI which is ignored by most converters is the potential problem in international traffic which occurs when the character sets used by sender and recipient do not match. This is most marked with vowels which can occur in foreign languages which will often appear as obscure characters when printed out or displayed using the English or American character sets. The DMX converters can, at the interchange interface, perform character substitution based on the character set which the interchange header identifies for the messages in it. The DMXMKTRN utility can be used both for incorporating a single conversion matrix in a table, and creating an external character conversion file for more sophisticated, syntax type, conversions. This facility can also be used for EBCDIC / ASCII conversion if required.