Methods of triggering a cold restart

[ChrisRCL]

Hi everybody! I apologize if I did not post this thread in it's proper location, but in my defense I am new to this forum and I have not had enough time to study the rules. I am posting this thread to seek help from anybody who has used Schneider PLCs such as TWDLCAADRF, regarding finding a way to trigger a cold restart without having to connect to the programming port. (Meaning without setting system bit %S0 to 1 ). I no longer have access to the PLC and I need to reset the program by means of cold restart. What I need is for the program to start fresh with the initial parameter values and not those already stored in RAM. From what I've read a cold restart can occur : 1-when loading a new application into RAM; 2-when power is restored with loss of application context; 3-when system bit %S0 is set to 1 by the program; 4-from the operator display when the PLC is in Stop mode. 1. First option is inapplicable for me since am no longer at the location of the PLC 2. Second option sounded promising at first, when I thought unplugging the RAM backup battery would do it for me. Then, upon a thorougher study of Twido's documentation, I found out that the internal battery is not user replaceable, so I got back to square 1. I've also found out that this battery lasts for 30 days when fully charged, but leaving the skid without power for 1 month is out of the question in my case. 3. Sure I can do this but that would mean that I need to get there and this is time and money costly and i would much prefer to avoid this. 4. This option is inapplicable for me as well. If anybody here has any ideas please let me know, any ideas would be much appreciated, Thank you!

[ChrisRCL]

Is there nobody who could give me an idea, no one at all?

[billysmithde2]

You have decided that you need a cold restart, but you have provided no information on why this is required. Perhaps if you describe what you need, rather than how to implement the solution you have decided upon already, more people could help? That looks like a Twido part number, and I have never used a Twido so do not know how to do a cold start. However, it's not obvious why you cannot code-in the parameters that you need to have changed or 'reset', rather than relying on the cold start. What is the trigger to make you want to do a cold restart?

[Goghie]

Or you can store "factory values" and restore them when you need them (look at %SW96 and %SW97). Additionally you can program digital input as "run/stop". Best regards, Vuckovic Goran. Edited June 28, 2014 by Goran Vuckovic

[ChrisRCL]

I must have not been quite clear, I'm sorry. Right now I need to reset the parameters of that specific Twido PLC. This resenting is only done when a cold restart occurs. I am currently 1200 Km away from the location the PLC is at and I can not code in the parameters remotely. Therefore I would need a procedure of some sort, which I can have a local operator over there(who does not have access to the programming port) walk through, in order to induce a hardware cold start. The basic idea is that I would very much want to avoid going back to that location. If I were there I could do it in a micro second, but I am NOT:D .

[ChrisRCL]

Yes, I know. Simply switching the PLC to STOP and then back to RUN won't solve my problem . Whenever a cold start occurs my program restores a bunch of "factory values" stored in the constants KW area during programming. I could have programmed a digital input to simply set system bit %S0 to 1 over the rising edge and now my problem would be solved by simply asking a worker over there to apply a 24V to that specific input. However at the time I wrote the software I did not foresee this problem so I did not code this feature in. The problem now is that I no longer have access to he PLC nor does anybody over at that specific location. So what I need is to find a way to trigger a cold restart of that PLC remotely.