HA for Balance 210+310

Hi. I have Balance 310 HW revision 3 with latest firmware. I use only 2 WAN ports, 3rd is disabled.
May I use my Balance 210 same HW revision and firmware in pair to 310 in Hight Avaliability mode?
Where could i find a firmware convertor (310 -->210)?

Countryman, when you say the 3rd WAN port is disabled, that leads me to believe it is a 210. If this is the case, then you have 2 of the same device along with the same HW revision. Correct me if I am wrong, but if this is the case then setting up a HA pair will work just fine.

Unfortunatelly, my 210 doesn’t accept configuration from 310.
When I enable HA option on both of them, the both trying to be Master at the same time.
Does anybody have idea how to make them work in HA?

Sounds like my assumption was not the case. You cannot HA pair different models – please check the device “status” tab where the serial is which lists the model number and hardware revision to confirm.