DALI error detection command
First check your physical layer setup before attempting to get the right query. Check that you are using an appropriate power supply (DALI requires a 11.5V to 20.5V d.c. power supply current limited to less than 250mA) which connects to your control device and the control gear (ballast).

Then send queries which you know will always get a response, such as 144 Query Status, or 153 Query Device Type. Check that your forward frame meets the timing requirements such as pulse width, start bit, stop bits, Manchester encoding and that your transmitter circuit is capable of pulling the power supply down to 4.5V at least during the low pulses.

When all this works, you are ready to try Command 146 Query Lamp Failure. If the gear has detected a failed or missing lamp, you should get a Yes response of 0xFF. In DALI, the No response is no response, the line stays in the high idle state. Bear in mind lamp failure can usually only be detected when the gear is driving the lamp to the on state, i.e it is looking for a lack of current when there should be current. So use Direct Arc Power with value 254 to set the lamp on full before Command 146 Query Lamp Failure.

It is unusual to state DALI commands as one hex byte. which makes me think you might be sending an 8 bit rather than 16 bit frame (bits counted before Manchester encoding). 8 bit frames are backwards frames, from the gear to the control device, produced in response to a query only. So make sure your first byte in the 16 bit forward frame is the address, start by using the broadcast address with only one gear (ballast) connected. If you have several gear connected, you need to either be able to handle collisions in the responses (which is normal and expected part of the way DALI works) or have software to set up the short addresses, which is quite a complex process involving randomisation and binary search.


0x92 = 146 Query Lamp Failure - this is the one you want. 
0x93 = 147 Query Lamp Power On - tell you if the lamp is currently on (ie the
gear is driving the lamp to the on state). However, the lamp might
have failed. 
0x9B = 155 Query Power Failure - tells you if the gear
has just been powered on and has not yet recieved any commands which
change its level from the default power on level.