Internet PLC Forum

Any news on the I2C-FRTC rollout?   I see substantial documentation for implimentation, so it must be close, no?

Nano-10 webpage requires the 0.htm and N.JS  (later version has been changed to M.JS). 0.htm occupies 4K, that means you can use the space from 2.xxx to L.xxx to store your JPG file. This is 20K bytes of file space which may just fit your JPEG file.

For PLC with r78 or later firmware you can use FRAM-RTC-256 to expand another 256K bytes of file space for storing webpage for used by the PLC for storing data into files.

I see, yes I had forgotten about the N file, though I knew it was there.  I understand writing it to U would not work, I was commenting that after the described sequence, I had a weird remnant file that showed up at "U".    I'll give it a try starting at "2.xxx", though when I do the math, saving it at "A" or "C" should offer plenty of space, if the slots were actually 2k each (13x2k).  
****update- success with the 16k  jpg stored at 2.jpg****

Clarification on the use of the FRAM-RTC-256. Is it only r78 and later?  Reason I ask is the Appendix A, Extended File system gives the thumbs up to r77 and later.  Has it been discovered r77 has limited functionality since 2011 when Appendix A looks like it was written?

A topping charge for two batteries could be 14.4 x 2 = almost 29 volts.  This wouldn't be an issue for the Nano?  I agree batteries have nice smooth power, but the Nano still has to be online when the batteries are getting recharged, so there will be voltage well over the 24+5%= 25.2v referenced in the spec.

The DC-DC power supply I mentioned is less than or equal to most the SLA batteries I'm looking at, and it would likely last longer than one battery.  There is no cost argument in favor of 24 volt that I can see.

On the Nano, 1&2 outputs sinking, 3&4 relays activated, 1-4 inputs sunk to ground, and the analogs pulling the maximum allowed, how many watts will the Nano use?  If someone doesn't recall immediately, there is design and testing notes for reference, no?

There is another reason to want everything but the Nano at 12 volts. The dc-dc power supply has a 30% loss.

My goal is to have the background image on the Nano so I don't need internet connection or a server of any kind for storing the background.  I've shrunk the jpeg file to under 16K, and tried storing at ip:port/a.jpg and it doesn't seem to work.  Removed file, tried then at c.jpg.   When using a browser to go to ip:port/c.jpg, I get "The image ?http://10.0.1.60:9083/c.jpg? cannot be displayed because it contains errors." in Foxfire: Safari shows nothing.  A few more clues.   The jpeg file opens fine before transfering to the Nano.  It shows it was transfered fine (all 16K or so) in Filezilla.  However, when I bring it back from the Nano to a folder on the PC, it only shows a hair over 2K, so for some reason, it is getting clipped.  Oddly, it leaves a remnant after the transfer of "U.jpg" on the Nano.  The Nano has only the other user file 0.htm (about 3.5K) on it so I really can't think of how the Nano would be short space. The 16K I'd think would occupy A-H, no?  The Nano is r76a, RTC-0 is installed.  Using Trilogi 6.43 over ethernet.
Thanks

Clipped.


The PLC is tested to withstand the following environmental stress:

a. Storage temperature: -20 to +85 degree C
b. Running temperature: 0 to 70 degree C.

So, I'm curious about winter operations.   The FMD88 sits in a plastic Nema 4x enclosure, which to some degree insulates the internals from outside cold.  Since it operates irrigation equipment, most of the use is not during the winter.   Is low temperatures harmful, so I need to add heat or shut down the system?  Or are low temps more just a inconvenience, say they make ADC's less accurate ?   ADC temps are likely the one thing that would still be of interest in the non-irrigation season.

Thank you for the kind offer of the development team.   It sounds like it is a bigger deal than I originally thought.  The virtual screen in simulation allows at least 40 characters, I thought it might be as simple as changing the way the web page handled it.   I hadn't considered the PLC need for 20 character limit, though I think that is what I have seen.  It would appear the PLC truncates the line rather than overflows to the next.

As with most things, there is more than one method for achieving a goal.   There is some instruction on exchanging screen information with timers and a custom function.  
http://www.tri-plc.com/yabbse/index.php?board=1;action=display;threadid=1579;start=msg5159#msg5159
I'll give that a try and see what can be done.

Chapter 5 discusses the analog inputs, of which there are 2 types.  In addition, there are two analog converters, each handling 4 of the eight.  Section 5.2.2 mixes discussion of points 7&8 and 5-8.  Are points 5&6 some how different than points 1-4, other than they are on a different converter? Please explain or if it is a typo, make a note so it may be corrected in the next revision.  (I'm reading Rev 1, Nov2011).

5.2.2   A/D #7 to 8
The DC input impedance of Analog inputs #7 & 8 are all 20.00K ohms (0.1%). This is not a problem when connected to a 0-5V low impedance analog source.
However, if you need to connect to 0-10V inputs or 4-20mA analog source to A/D #5 to #8, you have to take into consideration the low A/D input impedance in your design. The following figures show how to connect 4-20mA current source signals and 0-10V signals to the A/D inputs #7 to 8.