Thank you very much for your help, Argun. I understand that it is better to connect it honestly. I don't want to make it the wrong way either, so I am very grateful that you pointed that out.

I apologize for sending multiple comments in succession due to a communication error. I would like to delete the comment, but I can't find the action, so please understand that it was not intentional.

The requirements are as follows: ・A graph app to see changes in data ・measured data is about 2 bytes. ・measurement time is more than 24 hours. ・I want to obtain samples as finely as possible. Let me ask again, taking the above into consideration. ①Is iBeacon possible even if the app is in the background? ＞If I were trying to make a data logger, I'd log on the device... ②Does "log on the device" mean a connection via GATT communication? Also, does this refer to "b.", which ssmith_c answered?

The requirements are as follows: ・A graph app to see changes in data ・measured data is about 2 bytes. ・measurement time is more than 24 hours. ・I want to obtain samples as finely as possible. Let me ask again, taking the above into consideration. ①Is iBeacon possible even if the app is in the background? ＞If I were trying to make a data logger, I'd log on the device... ②Does "log on the device" mean a connection via GATT communication? Also, does this refer to "b.", which ssmith_c answered?

The requirements are as follows: ・A graph app to see changes in data. ・measured data is about 2 bytes. ・measurement time is more than 24 hours. ・I want to obtain samples as finely as possible. Let me ask again based on the above. Is it possible with iBeacon? In the background? ＞If I were trying to make a data logger, I'd log on the device and have an explicit... Does "log on the device" mean a GATT communication connection? Does this refer to "b.", which ssmith_c mentioned in his answer?