Let's keep this on track so for those future readers...
mikili said:
You have to use CPW instead of MOV instruction and you can do with the time and date whatever you want...I ran on this post and shared a solution, maybe it will be useful to someone, maybe even in seven years...
Or maybe never?...
Yes, CPW-wise you can "do with the time and date whatever you want"
after the RTC has been enabled. But not before that. Out-of-the-box the MicroLogix 1100/1400 RTC may only be manually enabled via the specific user task in the software which I had outlined in my previous post.
Did you read my post? If so, do you disagree with it?
The OP specifically asked...
crawler009 said:
...Is it possible to start the real time clock on a Micrologix 1400, from ladder...
As things stand, the answer to that question is categorically no.
Let's back this up with some hard facts from the manufacturer...
21067 - Using the CPW Instruction to Access RTC Data in MicroLogix Controllers
Access Level: TechConnect
Note that the title refers to "access" and not "enable". Within the text of that technote article, we are specifically instructed to...
Technote 21067 said:
...Make sure the RTC is not disabled. Enable the RTC by clicking on the Set Date & Time button...
Again, what you are outlining is only possible after we have first manually enabled the RTC.
This technote explains what happens if you do attempt to CPW write to the RTC Function File while it is disabled, as I pointed out to Ken previously...
63733 - MicroLogix - Fault 44h - INVALID WRITE TO RTC FUNCTION FILE
Access Level: TechConnect
Technote 63733 said:
...verify the following to prevent this fault: The RTC has been set once by going to the Controller Folder--> Function Files--> RTC Tab --> SET DATE & TIME while online...
...There is a status bit in the function file labeled RTC:0.DS. This bit is for feedback only and does not enable or disable the RTC; the bit cannot be modified in ladder logic or changed manually while offline or online...
And the final hammer blow on this matter...
49250 - How to enable/disable the MicroLogix 1100 or 1400 Real-Time Clock (RTC)
Access Level: TechConnect
Technote 49250 said:
...The MicroLogix 1100 and MicroLogix1400 Real-Time Clock (RTC) can only be enabled or disabled when you are online with the MicroLogix 1100 or MicroLogix 1400. In the RSLogix 500 project, go to the Function Files and click on the RTC tab. To enable the RTC, click on the 'Set Date & Time' button. To disable the RTC, click on the 'Disable Clock' button...
I'm sorry to have "disabled" your solution, but the status quo suggests that no amount of passing time, numerologically seven-yearly or otherwise, will improve upon its "real-time" standings.
Regards,
George