Documentation

PD Capabilities

This section documents the structure of the OSDP capability response(REPLY_PDCAP).

Message Structure ​

The REPLY_PDCAP response consists of 3-byte tuples with the followingmeaning:

ByteNameMeaningValue
0Function CodeFunction/feature codeSee below
1Compliance LevelLevel of compliance with above functionSee below
2Number of UnitsNumber of objects of this typeSee below

Function Code 1 — Contact Status Monitoring ​

Indicates the ability to monitor the status of a switch using a two-wireelectrical connection between the PD and the switch.

Compliance Levels:

  • 01 — PD monitors and reports circuit state without supervision, encoding per default interpretation of contact state.
  • 02 — Like 01, plus: PD accepts configuration of the encoding of open/closed circuit status to active/inactive status.
  • 03 — Like 02, plus: PD supports supervised monitoring. Operating mode per circuit is determined by configuration settings.
  • 04 — Like 03, plus: PD supports custom End-Of-Line settings within manufacturer guidelines.

Number of Units: Number of inputs.

Function Code 2 — Output Control ​

Provides a switched output, typically a relay, with active/inactive states.The CP can set the output state directly or specify a timed activation.

Compliance Levels:

  • 01 — PD can activate and deactivate the output per CP command.
  • 02 — Like 01, plus: PD accepts configuration of the output driver to set the inactive state (supports fail-safe/fail-secure modes).
  • 03 — Like 01, plus: PD accepts timed commands specifying output state for a duration.
  • 04 — Like 02 and 03 combined.

Number of Units: Number of outputs.

Function Code 3 — Card Data Format ​

Indicates the form in which card data is presented to the CP.

Compliance Levels:

  • 01 — PD sends card data as a raw bit array, up to 1024 bits.
  • 02 — PD sends card data as a BCD character array, up to 256 characters.
  • 03 — PD can send card data as either a bit array or BCD character array.

Number of Units: N/A, set to 0.

Function Code 4 — Reader LED Control ​

Indicates the presence and type of LEDs.

Compliance Levels:

  • 01 — PD supports on/off control only.
  • 02 — PD supports timed commands.
  • 03 — Like 02, plus bi-color LEDs.
  • 04 — Like 02, plus tri-color LEDs.

Number of Units: Number of LEDs per reader.

Function Code 5 — Reader Audible Output ​

Indicates the presence and type of an audible annunciator (buzzer or tonegenerator).

Compliance Levels:

  • 01 — PD supports on/off control only.
  • 02 — PD supports timed commands.

Number of Units: Number of audible annunciators per reader.

Function Code 6 — Reader Text Output ​

Indicates that the PD supports a character-based text display.

Compliance Levels:

  • 00 — No text display support.
  • 01 — PD supports 1 row of 16 characters.
  • 02 — PD supports 2 rows of 16 characters.
  • 03 — PD supports 4 rows of 16 characters.
  • 04 — TBD.

Number of Units: Number of textual displays per reader.

Function Code 7 — Time Keeping ​

Indicates date and time awareness or time-keeping ability.

Compliance Levels:

  • 00 — PD does not support time/date functionality.
  • 01 — PD understands time/date settings via osdp_TDSET.
  • 02 — PD can locally update the time and date.

Number of Units: N/A, set to 0.

Function Code 8 — Check Character Support ​

Indicates CRC-16 capability. All PDs must support checksum mode.

Compliance Levels:

  • 00 — PD does not support CRC-16; checksum only.
  • 01 — PD supports 16-bit CRC-16.

Number of Units: N/A, set to 0.

Function Code 9 — Communication Security ​

Indicates the extent of Secure Channel Communication support.

Compliance Levels (bit map):

  • 0x01 — (Bit 0) AES128 support.
  • 0x02 — (Bit 1) to be defined.

Number of Units (bit map):

  • 0x01 — (Bit 0) Default AES128 key, as defined in APPENDIX D.
  • 0x02 — (Bit 1) to be defined.

Function Code 10 — Receive Buffer Size ​

Indicates the maximum size of a single message the PD can receive.

Compliance Level: LSB of the buffer size.

Number of Units: MSB of the buffer size.

Function Code 11 — Largest Combined Message Size ​

Indicates the maximum size of a multi-part message the PD can handle.

Compliance Level: LSB of the combined buffer size.

Number of Units: MSB of the combined buffer size.

Function Code 12 — Smart Card Support ​

Indicates whether the PD supports transparent mode for communicating directlywith a smart card.

Compliance Levels:

  • 0 — PD does not support transparent reader mode.
  • 1 — PD supports transparent reader mode.

Number of Units: Unused, send 0x00.

Function Code 13 — Readers ​

Indicates the number of credential reader devices present.

Compliance Levels (bit fields): 0x01 (Bit 0), 0x02 (Bit 1).

Number of Units: Number of readers.

Function Code 14 — Biometrics ​

Indicates the ability of the reader to handle biometric input.

Compliance Levels:

  • 0 — No biometric support.
  • 1 — Fingerprint, Template 1.
  • 2 — Fingerprint, Template 2.
  • 3 — Iris, Template 1.

Number of Units: Number of readers.