Epson TM-P60II Technical Reference Manual page 107

The iOS application receives the same data from the printer multiple times
Situation
Although the printer only sends data (such as the status) once to the iOS device, the application on the iOS
device may receive the data multiple times.
Conditions
If no data is sent between the printer and the iOS device for at least 30 seconds during Bluetooth connection, the
iOS device switches to power-saving mode. This problem occurs if the printer sends data to the iOS device
while it is in power-saving mode.
The following are examples of when this occurs.
 When the printer performs status communication with a command (DLE EOT, GS I, and so on)
 When the printer sends an ASB
In the following situations, this does not occur.
 When the iOS device sends data to the printer
 When data is sent to the iOS device before it switches to power-saving mode (less than approx. 30 seconds)
after the printer has received data from the iOS device
 When using the SDK from Epson (however, this may occur when receiving data from a printer using a com-
mand transmission/reception API)
Solution
If no data is sent between the printer and the iOS device for at least 30 seconds, use the following steps to send
data.
1) Before sending data, send 100 bytes of dummy data to the printer. As long as it is not related to printing or
commands, anything can be used as the dummy data, however we recommend using 00h.
2) Set a waiting time of 100 milliseconds.
3) Send the data.
The iOS application cannot receive the data sent from the printer
Situation
Although the printer sends data to the iOS device and the data is received by the iOS device, depending on the
combination of the iOS version and the iOS device, the iOS application may not be able to receive the data.
Conditions
This may occur in combinations of the following conditions.
 iOS version: 7.1, 7.1.1
 iOS device: iPhone 5s, iPhone 5c, iPhone 5, iPad Air, iPad mini with Retina display, iPad (4th generation),
iPad mini, iPod touch (5th generation), iPhone 4s, iPhone 4, iPad (3rd generation), iPad 2
 Printer firmware version: 6.11 ESC/POS or earlier
 Application processing: If the Bluetooth port is closed and then reopened while the application is running.
Appendix
107