What is the expected delay on a dali ballast from actioning a Direct Arc Power command

Question

I am sending toggling Direct arc power commands to a LED driver. ( OFF / ON ) at an equal interval of 500mS. I am monitoring the dali bus commands with a Lunatone USB interface and I can see that the Led driver sometimes missed the ON - interestingly it never missed the off command. The interval between commands was then extended to 1500mS. This then showed that there it was not missing the command but in fact a notable delay happening occasionaly with the ON command.

There is only the one Dali device on the bus. I'm wondering what the specification is for this.

Edit: Looking at the Dali Specification ( Standards titles ONLY ) What is the difference between : 1) BS EN 62386-102:2014 CONTROL GEAR 2) BS EN 62386-103:2014 CONTROL DEVICES

(one wonders why they would not be in the same standard as probably much is duplicated)

Answer 1

The specification requires the command to be handled immediately after the stop condition which is 2.4ms from the last edge of the message. We can see this from the requirement to measure the fade time from the stop condition that triggers it.

Part 102 is Control Gear - This is the IEC term for equipment that is connected directly to lamps, commonly called ballasts or drivers. Part 103 is Control Devices - These are such items as controllers which send message to gear to change their state and level. There is very little commonality between 102 and 103 because the common requirements are now gathered in the expanded part 101.