Hi guys, me again.
We've been dealing with this Sunny Island system as you can probably remember, and SMA has swapped out my Sunny Island - well they sent it and I swapped it out - with almost all the bugs worked out the tech noticed something weird, and so did I. It seems my system will be snoozing right along at night with a light 8-12A load on my end, no generator, grid, or solar active, all of a sudden my Sunny Island will log battery current IN anywhere from 400A to almost 4000A. The tech at SMA suggests it is a communications error with the Classics, MODBUS/Canbus, and the Sunny Island - but for the first time in forever they all seem to be working just as they should, the Sunny Island sees the two Classic 250V's as SIC-40's, just as designed. But then the tech never heard of 'i-loop' which I initiated to solve the chronic W309 problem, so there is that. The other unit never logged anything odd like this, the replacement from SMA actually looks to be a used unit that might have been dropped and glued back together with RTV. I think it is the Sunny Island, please tell me my Classics can't do this. Nowhere in any of my mymidnite2 data do I ever see any impossibly weird numbers.
Very strange...
Where does the SMA say that current is coming from ?
They say it doesn't exist.
Where are you getting the information exactly ?
From the logs on the memory card that resides in the slot on the Sunny Island. The attached chart was done by SMA support from data from the card.
On the chart - the top line is what is actually happening, all the lines down to ~400 and around ~3500A are of course the aberrant readings.
IF it was a communications issue with the Classics just unplugging the data cable would remove that from the system while still allowing my Classics to count my Ah in the night. Right? I'm going to try to prove or disprove this as numbers that big are scaring the whee out of me... well obviously I'm not putting 175,000 watts to my battery all of a sudden.
I don't think it is because of a communications error because error detection would (or should) keep that from happening. Even if you plug in and plug out comms while it is communicating.
I dont see this being likely, The registers that hold output current on the classic are not large enough to hold those size values.
Thank you, I'll pass that along.
I pulled the comm cable from the Classic to the MODBUS/Canbus adaptor at 6:22PM on 11/09 and sent in the data from my memory card the next morning to SMA. Here is their reply:
- Hello Michael,
The current spikes stopped when the Midnite unit was disconnected. The last spike was recorded at 6:22 PM on 11/9. Based on the data, I see the Midnite device seems to stop communicating at 6:45 PM. See attached battery current graph. In my mind, this confirms that the issue has to do with the communication between the SI and Midnite.
Not sure what to say there. I guess a bad cable could be corrupting packets? I cant see the classics being responsible as they dont hold values that large
The blue cables I bought from you guys that run from the Classics to the MODBUS/Canbus are standard cables of some sort? I've got lots of Cat5E-600 cables and ends leftover from installing the RSS...
They are a standard 4 conductor phone cable.
Thank you!
Quote from: FNG on November 11, 2020, 01:58:19 PM
They are a standard 4 conductor phone cable.
Telephone 4 wire cable for RJ14 is not the same as 4 pair ethernet using RJ-45
https://en.wikipedia.org/wiki/Ethernet_over_twisted_pair
https://en.wikipedia.org/wiki/Registered_jack#RJ11,_RJ14,_RJ25_wiring
The connectors are the same style, but vary in the width and number of pairs they carry
It is true the current spikes stopped at 6:22 PM when I unplugged the data cable from the Classic to the MODBUS/Canbus adaptor - but it also appears true that they did not return after plugging it back in at 8:30 AM the next day. Several days now, I don't see the current spikes. Thanks guys, just a weird glitch it appears.
NOPE! I was WRONG! It didn't make the current spikes with the Classics unhooked but does when hooked back to the MODBUS/Canbus adaptor. SMA's solution is to 86 the MODBUS/Canbus and do DC only with the Classics doing their thing by their lonesome. I really didn't spend all this money for this to be the solution. Can you help, please? I went with all this MidNite stuff because it was supposed to work with my Sunny Island!
Unfortunately we do not have enough information about SMA's canbus communications protocol and internal software workings to have any good idea why their unit is giving you bogus current information.
What happens if you keep just the Midnite canbus interface connected but turn off the external charge controllers in the SMA Sunny Island menu ?
Do you still get the bogus information ? No Classics, just the interface as you found.
Yeah, no that is what led to the SOC issue in the first place. The only thing different between the system that works and this one was the addition of the RSS, which has issues of its own in another thread - could these be related issues?
Quote from: Trukinbear on November 21, 2020, 12:25:13 AM
Yeah, no that is what led to the SOC issue in the first place.
I do not understand regarding my question in my previous post.
Having the external charge controllers connected to the com but not turned on in the Sunny Island is what FUBAR'd the other Sunny Island.
I'm trying several combinations of configs in an effort to find my problem via the process of elimination. Tonight we've un-networked the Classics and are presenting only the primary via the MODBUS/Canbus to the SI.
Preliminary data suggests the comm errors are related to the (intermittent unused address 11) (previously mirrored display issue) 2nd networked Classic 250 which has acted wonky since around the time the repaired 1st Classic 250 came back online.
I've done the VMM both with the MNGP and the jumpers, neither of which actually reset everything. How do you wipe everything clean for real?
Maybe it's the modbus-canbus interface having some kind of issue ?
Quote from: Trukinbear on November 22, 2020, 03:07:26 PM
Preliminary data suggests the comm errors are related to the (intermittent unused address 11) (previously mirrored display issue) 2nd networked Classic 250 which has acted wonky since around the time the repaired 1st Classic 250 came back online.
I've done the VMM both with the MNGP and the jumpers, neither of which actually reset everything. How do you wipe everything clean for real?
The VMM resets all the important registers. Unfortunately that's about the best you can do. One thing you could do is pull all the registers from another classic and import them to this one but I don't see that helping.
If there is a defect with this classic causing loss of coms it wont be related to values in a register. I would suggest emailing or calling support and see what they have to say.
Ok, I've got two Trouble Tickets in, one for this and one for the (maybe related?) problem with my RSS Birdhouse. Fingers crossed! In the meantime, I've over paneled the one operating Classic as this time of year my panels never exceed 50% of nominal rated power anyway.
The replacement unit has arrived and has been installed in place of this Classic 250 - appears to be working properly and I've yet to record a current spike. Hope I'm not speaking too soon, but it appears to be - yes, my classic can be responsible for this.