FoxESS Community - Owners & Installers Forum

Hi all, this is my 1st post here but I have used this site since my system was installed last July and very useful it is.

Last week I changed to Agile Octopus tarriff and I tried the Grid Charging option but there were some issues with it and wanted to try Scheduled Modes but this was unavailable so I had the firmware updated and ended up with the following:

Master: 1.40
Slave: 1.04
Manager: 1.56
DataLogger: 2.02
BMS: 1.007

Trouble is that now I can't change settings like MinimumSoC-OnGrid or the Schedule Modes without getting a 44098-Write failure error, but I can change some settings like MaximumSetChargeCurrent.

I've contacted Fox Support but they don't work weekends, anyone here have know how to fix this please?

Schedules are good but you can't change some inverter settings whilst they are enabled or you'll get a 44098 write error (or if you use modbus it'll simply get changed back).

Main things being with schedules enabled you can't manually change workmode, or battery reserve (min soc on grid)

Schedules are enduring and run in the inverter manager so when they have completed the work mode will return to 'Self Use' but the min soc (battery reserve) will remain at it's last setting - so for example if you raise it to 80% in a feed-in schedule, when the schedule completes the inverter will return to self-use with a min soc of 80%; it's always better to set a schedule for times in between so the inverter is set to what you want as you won't be able to change them.

When you are re-writing your schedules it is best to disable scheduler, change your schedules to what you want and then re-enable it.

Thanks Dave, I'll check to see if it thinks it's on a schedule (not sure how though) but I don't think it is as I can set a Charge from Grid slot via modbus and it activates and stops OK.

I thought if it was on a schedule or even just with schedules enabled then Charge From Grid is disabled?

I set a new schedule with a duration of 15mins and it's run it's time so should not now be on one but I still can't change MinimumSoC-OnGrid unless I use modbus.

Interesting that there are 96 schedule slots available in this version

Once a schedule has run it is set to run every day, you must disable the scheduler or it will not let you change them

When I try and set my mode scheduler it sometimes says “Failed to get device timer mode settings” and then won’t let me set anything

Thanks Dave, I set-up some Schedule slots; let them run; then disabled them all - now I can change MinimumSoC-OnGrid and all the other settings.

paul@standrewswells.co.uk wrote: ↑Sun Aug 31, 2025 1:07 pm

paul@standrewswells.co.uk wrote: ↑Sun Aug 31, 2025 1:07 pm When I try and set my mode scheduler it sometimes says “Failed to get device timer mode settings” and then won’t let me set anything

Paul, just got this message myself when I went back into Mode Scheduler How do we get out of this now?

John
With me it is intermittent and if I retry later it often works

When you read/write schedules it requires real time access to the inverter - if the Fox cloud is slow in responding, or your broadband is slow, or the wifi signal at the inverter is low it often results in this error. It usually works ‘later’ but worth checking the quality of wifi signal at the inverter - in the V2 app if you click on Device and click the image of the datalogger it will show you the current signal strength.

Thanks Dave
Paul

Thanks from me as well Dave, now working again.