Serial port is enabled in BIOS.
The same device with the same cable successfully connected to another motherboad (asus z97-a), so device problem is excluded. Tried Win2012,Win2008R2,Win8.1
Should I change something else on this motherboard to make it work with UPS by serial port?
The settings that can be changed at a BIOS level for the serial port are under Advanced> Serial Port Configuration:
Serial A Enable
Serial A Address
Serial A IRQ
In order to know how to configure these settings we strongly recommend checking with APC directly.
On asus Z97-A I have next settings:
Serial port Enable
IO = 3F8h
IRQ = 4
and device is working fine
On s1200spl I have next settings:
Serial A Enable = Enable
Serial A Address = 3F8h
Serial A IRQ = 4
and no responce from device
Do you really think that connection problem is on the UPS side?
As far as I understand you are following settings for an Asus* board and these settings will vary from manufacturer. We can confirm that from our side there is no specific documentation explaining how to configure this specific APC device; reason why we recommend contacting the manufacturer directly. There is also the chance of incompatibility since we have not tested this UPS and you can confirm that with the manufacturer as well.