Today I tried to figure out why our Symmetra was not seeing the AP9612TH environmental card that was installed over the Christmas shutdown at work. I did read a document about what order the cards must be installed based on slot number. Unfortunately with the cards installed there is no slot numbering visible. So after a few quick emails with APC/MGE tech support I found out the following.
On our Symmetra one slot is by itself to the left. The other two are stacked vertically on the right. This orientation is based on facing the back of the unit where the slots are. According to support the slot by itself to the left is the third slot, so that makes the top right the first slot. They also told me thankfully that the symmetra card slots are hot swappable. Normally on UPS Smart UPS units they are not and you had best power down the unit first before tampering with any smartslot cards.
So, tomorrow we shall see if this works. I just have to swap the 9617 Management card and the 9612TH environmental card. After a minute for the management card to reboot I should then be able to see the environmental sensor and setup our temperature and humidity alerts.