Documentation

Command and Reply Codes

Reference for OSDP commands and replies — the full message set exchanged between a control panel (CP) and peripheral device (PD) on the OSDP bus.

The following commands and replies are reserved by the protocol for various actions. The tables below show their descriptions and support status in this implementation.

The secure-channel commands — CMD_KEYSET, CMD_CHLNG, and CMD_SCRYPT — are described in Secure Channel.

Commands ​

CommandValueDescriptionSupport
CMD_POLL0x60Poll✓
CMD_ID0x61ID Report Request✓
CMD_CAP0x62Peripheral Device Capabilities Request✓
CMD_DIAG0x63Diagnostic Function–
CMD_LSTAT0x64Local Status Report Request✓
CMD_ISTAT0x65Input Status Report Request✓
CMD_OSTAT0x66Output Status Report Request✓
CMD_RSTAT0x67Reader Status Tamper Report Request✓
CMD_OUT0x68Output Control Command✓
CMD_LED0x69Reader LED Control Command✓
CMD_BUZ0x6AReader Buzzer Control Command✓
CMD_TEXT0x6BReader Text Output Command✓
CMD_RMODE0x6CReader Mode Set✕
CMD_TDSET0x6DTime and Date Set✕
CMD_COMSET0x6ECommunication Configuration Command✓
CMD_BIOREAD0x73Scan and send biometric data✓
CMD_BIOMATCH0x74Scan and match biometric data✓
CMD_KEYSET0x75Encryption Key Set✓
CMD_CHLNG0x76Challenge and Secure Session Initialization Request✓
CMD_SCRYPT0x77Server's Random Number and Server Cryptogram✓
CMD_ACURXSIZE0x7BMaximum Acceptable Reply Size✓
CMD_FILETRANSFER0x7CFile transfer command✓
CMD_MFG0x80Manufacturer Specific Command✓
CMD_XWR0xA1Extended write data✕
CMD_ABORT0xA2Abort PD operation✓
CMD_PIVDATA0xA3Get PIV Data✕
CMD_GENAUTH0xA4Request Authenticate✕
CMD_CRAUTH0xA5Request Crypto Response✕
CMD_KEEPACTIVE0xA7Keep secure channel active✓

Responses ​

ResponseValueDescriptionSupport
REPLY_ACK0x40General Acknowledge, Nothing to Report✓
REPLY_NAK0x41Negative Acknowledge – SIO Comm Handler Error Response✓
REPLY_PDID0x45Device Identification Report✓
REPLY_PDCAP0x46Device Capabilities Report✓
REPLY_LSTATR0x48Local Status Report✓
REPLY_ISTATR0x49Input Status Report✓
REPLY_OSTATR0x4AOutput Status Report✓
REPLY_RSTATR0x4BReader Status Tamper Report✓
REPLY_RAW0x50Card Data Report, Raw Bit Array✓
REPLY_FMT0x51Card Data Report, Character Array✓
REPLY_KEYPAD0x53Keypad Data Report✓
REPLY_COM0x54Communication Configuration Report✓
REPLY_BIOREADR0x57Biometric Data✓
REPLY_BIOMATCHR0x58Biometric Match Result✓
REPLY_CCRYPT0x76Client's ID and Client's Random Number✓
REPLY_RMAC_I0x78Client Cryptogram Packet and the Initial R-MAC✓
REPLY_BUSY0x79PD Is Busy Reply✓
REPLY_FTSTAT0x7AFile transfer status✓
REPLY_PIVDATAR0x80PIV data reply✕
REPLY_GENAUTHR0x81Authentication response✕
REPLY_CRAUTHR0x82Response to challenge✕
REPLY_MFGSTATR0x83Manufacturer specific status✕
REPLY_MFGERRR0x84Manufacturer specific error✕
REPLY_MFGREP0x90Manufacturer specific reply✓
REPLY_XRD0xB1Extended read response✕

LibOSDP Behavior Note ​

For CMD_MFG, immediate command response follows normal callback ACK/NAK rules: callback return < 0 yields REPLY_NAK, callback return >= 0 yields REPLY_ACK. If the application wants to send REPLY_MFGREP, it must do so asynchronously by submitting an OSDP_EVENT_MFGREP event, which is then delivered on a subsequent CMD_POLL cycle.