There are not many modular K series PLCs still in operation but it is still possible to convert the K series application to a Qn PLC as detailed below. It should be pointed out that availability of the items listed may mean that conversion is not possible.

Design Constraints

To convert from K series PLC it is first necessary to obtain a copy of the PLC application as a DOS MEDOC software file. If this is not available it can be uploaded into DOS MEDOC from the PLC but the following items are required:

  • DOS MEDOC PLC programming software version 3.11 (this supports the K PLC);
  • A PC capable of running DOS MEDOC with serial comms (for example Windows 98);
  • The K6HGPFE programming interface for the K series PLC;
  • An SC-02 powered communications cable; and
  • A K78CBL cable from the SC-02 to the RS232 port of the PC.

An alternative to the above is to remove the PROM from the PLC and use the A6GPP programmer to read the application.

Once the PLC application is in DOS MEDOC, the PLC type can be changed to an A series PLC such as an A2, and then saved.

At this point the MEDOC application can be imported into GX Developer. A new and empty A2N PLC project must first be created, and then the DOS MEDOC file imported as shown.

The final part of the conversion is to change the PLC type to Q series and save the project in GX Developer.


  1. Potentially old hardware and software items are required that may not be available.
  2. A check MUST be made at all stages of the conversion process to ensure that the application program is still valid and functions correctly.
  3. Potentially certain instructions within the application program may not be supported.
  4. Unless an original DOS MEDOC application is available, the PLC program will not be commented or have any named I/O.

Further Information

For further information, please refer to Mitsubishi support.

[et_pb_divi_related_posts_module _builder_version="3.0.106" header_text="Related Posts" posts_count="5" posts_source="tags" /]