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
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


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