Modicon 484 reprogramming

[Sashyanth 0]

Hello we recently purchased an offset printing machine from a closed print shop which is controlled by a Modicon Gould 484 plc.  Due to the machine being disconnected from power for quite a bit the batteries had drained and the plc has lost its memory.  However along with the documentation of the machine we received a backup program for the 484 on a floppy disk in sta format.  I would like to know if anyone can help and advise me on how to reprogramme the 484 and also about the necessary software and cables required.  We have checked the machine and all systems are functional 

[Crossbow 277]

Good luck, that's an ancient PLC which only offered DOS based software.  I don't have info on the cables but Modsoft may be able to open the files you have.  Assuming the floppy disk is still any good.

[collinsd70 30]

Regarding the software..you should be able to open this via MODSOFT or ProWorxNXT.

There is a application in the ProWorx directory that will convert your code from a number of file extensions.

Accessing the CPU could be done via Modbus or Modbus Plus- I built a serial cable myself that I used to engineer code on the 484 and Quantum platforms.

If you want me to take a look at opening/ converting your code. Feel free to give me a PM.

[collinsd70 30]

Just a side note- as per Crossbows comment, MODSOFT is Dos Based and can only run on anything previous to Windows XP. 

I used Serial cables in ProWorx NXT without any issues.

[Crossbow 277]

Didn't know NXT could get online with anything older than a 984.

[Sashyanth 0]

Thanks for the info, We have replaced the 484 with a new PLC and uploaded the program using the ladder diagram. So we will not be using the 484 anymore

[Modiconbob 2]

Crossbow, you are correct! NXT will NOT communicate with a 484. A 484 is asynchronous and also needs a hardware asynchronous to serial convertor (Modicon J470).