#POLL HCE sub instruction
Use this command to poll the status of the Host-based Card Emulation subsystem, and to retrieve the incoming C-APDUs (commands sent by the remote reader once the NFC channel is open).
See CONTROL_HCE instruction on how-to start HCE.
#Command format
| Field |
Value |
Remark |
| CLA |
FF |
|
| INS |
F7 |
HCE instruction |
| P1 |
00 |
POLL HCE sub instruction |
| P2 |
Timeout |
See table below |
| Lc |
Absent |
|
| DataIn |
Absent |
|
| Le |
00 |
|
#Timeout (P2)
| Bits |
Remark |
| 7 |
RFU must be 0 |
| 6 |
RFU must be 0 |
| 5-0 |
Timeout in seconds
000000 : no timeout, the device returns the current status immediately
000001 to 111111 : timeout between 1 and 63 seconds. The device waits until the status changes or the timeout occurs |
#Response
| Field |
Value |
Remark |
| DataOut |
C-APDU |
The command received for the remote NFC reader, if some
The Host shall then construct a response (R-APDU) and send it to the remote reader as soon as possible, using PUSH HCE |
| SW |
HCE status |
See table below |
#HCE status (SW)
| SW1 |
SW2 |
Meaning |
6F |
38 |
HCE not started |
6F |
xx |
Other fatal error |
91 |
00 |
HCE started, no external RF field |
91 |
01 |
HCE started, external RF field present, card not selected |
91 |
03 |
HCE started, external RF field present, card selected (ATS sent) |
91 |
07 |
HCE started, external RF field present, card de-selected (DESELECT or RF off/on) then selected again (ATS sent) since last call |