PLC 5/20 and 5/40

Hello Experts;
Good day. I face a problem that the programme is wash from the PLC 5/20 while internal battery is found ok and there is no indication or alarm of the backup battery.
Please help me what are the possible reasons and how i fix it?

Regards

I've seen this serveral times...
I hope that you have a back-up of the program..
How to fix this, I've never fixed it, just reloaded the program, and run!

Goodluck..

Check ground. Make sure all inductive loads have surge protection. And install a UPS and
surge protection for the PLC's power. The UPS installation worked for me.

Hello Mickey;
The power of the PLC 5/20 is supplying by the battery charger. If mains fails its enegise.
I will check the surge detector on the power supply of the PLC. Thanks for the idea.

But can you help me or give me any video tutorials or book in which i read the PLC 5/20 or 5/40 programming, How to install the software if it is washed, How to edit the values how to read and write data, how install the firmware i.e programming structure. I have RSLogix 5.0 version 7.4 i am new one with this.
do u have any wire configration pin to pin to make the serial communication with Laptop have rslogix 5 to plc 5/20 and 5/40.
Please guide me?

Regards

http://literature.rockwellautomation.com/idc/groups/literature/documents/gr/lg5-gr002_-en-p.pdf

http://literature.rockwellautomation.com/idc/groups/literature/documents/um/1785-um001_-en-p.pdf

http://literature.rockwellautomation.com/idc/groups/literature/documents/qr/1785-qr001_-en-p.pdf

http://literature.rockwellautomation.com/idc/groups/literature/documents/rm/1785-rm001_-en-p.pdf

http://literature.rockwellautomation.com/idc/groups/literature/documents/um/1785-um012_-en-p.pdf

http://www.youtube.com/user/RonBeaufort

Guys,
do you have the version 7.4 software you can send??? i have a license but not that version. i only have version 8. thanks,