Password Protection vs. Upload Protection: Using AFPX-MRTC to Remotely Update Programs

May 08, 2012
By Anonymous

Remotely Updating Programs

Panasonic can help companies easily make updates to a PLC program for remotely located end users. In the case of program improvements or fixes, it’s important not to give the ability to view or modify their proprietary programming logic. There are a few ways to do this, such as using a GT Series HMI SD Card slot, or FPLoader.

However, this blog post will focus on the AFPX-MRTC. This unit has functions like Realtime Clock (RTC), and RTC with master memory, while implementing either password protection, upload protection or both.


                                                                                             Figure 1

Using AFPX-MRTC For Updates

Imagine a system manufacturer in New Jersey, USA needing to update an end users located in Bangkok, Thailand. It’s not economically convenient for the manufacturer to send a field engineer across the globe to perform a program fix.  Moreover, if the PLC isn’t connected to an online network, then remote reprogramming is not an option. 

Regardless, the end user holds the manufacturer accountable if the program contains errors, or needs updating. An economical, safe, and easy way to make updates is via the AFPX-MRTC.  The MRTC is a small device that will plug into the top of any FPX series PLC, and will automatically reprogram the control unit without the need for software or technical knowledge. The MRTC supports password protection and upload protection, giving the manufacturer peace of mind regarding their proprietary code.

Password Protection

Password protection is protecting the program code from being changed/altered/modified by the programmer. This function will restrict writing and reading of ladder programs or system registers.

  • Case 1: PLC A and PLC B are password protected. The MRTC uploaded the program code from PLC A. The MRTC is then connected to PLC B. Transfer from MRTC to PLC B is restricted.
  • Case 2: PLC A is password protected, PLC B has no protection. The MRTC uploads the program code from PLC A. The MRTC is then connected to PLC B and transfer from MRTC to PLC B is performed. PLC B is now password protected and contains the program code, data, and password from PLC A. Now PLC B program now can not be edited without clearing the password.

Upload Protection

The upload protection function prohibits extracting programs and system registers by disabling the uploading on the FPX. There is no way to disable upload protection. To remove upload protection, the program must be over-written, or PLC cleared. Keeping a copy of the protected program is the responsibility of the programmer. If this function is enabled, uploading ladder programs from the PLC to the PC, or transferring programs to the MRTC, are impossible. FPX, FPSigma ver. 3.0 and up, and FP0R PLCs support this feature.

  • Case 1: Using PLC software, program A is transferred to MRTC and upload protection is selected for transfer. The MRTC now holds the PLC program A and can transfer this code to any non password protected PLC. PLC B received the transfer from MRTC and now has contents of program A and protection. PLC B is connected to PC and uploading is restricted.
  • Case 2: PLC A is upload protected. Using PLC software program or MRTC unit, upload protection is impossible.

Password protection and upload protection together will completely secure the PLC from uploading program code data or downloading a new program code to the PLC.


                                                                                                           Figure 2