PD Capabilities

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

Message Structure

The REPLY_PDCAP response is a set of 3 bytes, with the following positional meaning.

Byte	Name	Meaning	Value
0	Function Code	Function/feature code	See Below
1	Compliance Level	Level of compliance with above function	See Below
2	Number of Units	Number of objects of this type	See Below

Function Code 1 - Contact Status Monitoring

This function indicates the ability to monitor the status of a switch using a two-wire electrical connection between the PD and the switch. The on/off position of the switch indicates the state of an external device.

The PD may simply resolve all circuit states to an open/closed status, or it may implement supervision of the monitoring circuit. A supervised circuit is able to indicate circuit fault status in addition to open/closed status.

Compliance Levels:

01 - PD monitors and reports the state of the circuit without any supervision. The PD encodes the circuit status per its default interpretation of contact state to active/inactive status.
02 - Like 01, plus: The PD accepts configuration of the encoding of the open/closed circuit status to the reported active/inactive status. (User may configure each circuit as “normally closed” or “normally open”.)
03 - Like 02, plus: PD supports supervised monitoring. The operating mode for each circuit is determined by configuration settings.
04 - Like 03, plus: the PD supports custom End-Of-Line settings within the Manufacturer’s guidelines.

The End-Of-Line circuit parameters are defined by the manufacturer of the PD.

Number of Units:

The number of Inputs.

Function Code 2 - Output Control

This function provides a switched output, typically in the form of a relay. The Output has two states: active or inactive. The Control Panel (CP) can directly set the Output’s state, or, if the PD supports timed operations, the CP can specify a time period for the activation of the Output.

Compliance Levels:

01 - The PD is able to activate and deactivate the Output per direct command from the CP.
02 - Like 01, plus: The PD is able to accept configuration of the Output driver to set the inactive state of the Output. The typical state of an inactive Output is the state of the Output when no power is applied to the PD and the Output device (relay) is not energized. The inverted drive setting causes the PD to energize the Output during the inactive state and de-energize the Output during the active state. This feature allows the support of “fail-safe/fail-secure” operating modes.
03 - Like 01, plus: The PD is able to accept timed commands to the Output. A timed command specifies the state of the Output for the specified duration.
04 - Like 02 and 03 - normal/inverted drive and timed operation.

Number of Units:

The number of Outputs.

Function Code 3 - Card Data Format

This capability indicates the form of the card data is presented to the Control Panel.

Compliance Levels:

01 - the PD sends card data to the CP as array of bits, not exceeding 1024 bits.
02 - the PD sends card data to the CP as array of BCD characters, not exceeding 256 characters.
03 - the PD can send card data to the CP as array of bits, or as an array of BCD characters.

Number of Units:

N/A, set to 0.

Function Code 4 - Reader LED Control

This capability indicates the presence of and type of LEDs.

Compliance Levels:

01 - the PD support on/off control only
02 - the PD supports timed commands
03 - like 02, plus bi-color LEDs
04 - like 02, plus tri-color LEDs

Number of Units:

The number of LEDs per reader.

Function Code 5 - Reader Audible Output

This capability indicates the presence of and type of an Audible Annunciator (buzzer or similar tone generator)

Compliance Levels:

01 - the PD support on/off control only
02 - the PD supports timed commands

Number of Units:

The number of audible annunciators per reader

Function Code 6 - Reader Text Output

This capability indicates that the PD supports a text display emulating character-based display terminals.

Compliance Levels:

00 - The PD has no text display support
01 - The PD supports 1 row of 16 characters
02 - the PD supports 2 rows of 16 characters
03 - the PD supports 4 rows of 16 characters
04 TBD.

Number of Units:

Number of textual displays per reader.

Function Code 7 - Time Keeping

This capability indicates that the type of date and time awareness or time keeping ability of the PD.

Compliance Levels:

00 - The PD does not support time/date functionality
01 - The PD understands time/date settings per Command osdp_TDSET
02 - The PD is able to locally update the time and date

Number of Units:

N/A, set to 0.

Function Code 8 - Check Character Support

All PDs must be able to support the checksum mode. This capability indicates if the PD is capable of supporting CRC mode.

Compliance Levels:

00 - The PD does not support CRC-16, only checksum mode.
01 - The PD supports the 16-bit CRC-16 mode.

Number of Units:

N/A, set to 0.

Function Code 9 - Communication Security

This capability indicates the extent to which the PD supports communication security (Secure Channel Communication)

Compliance Levels:

This field is a bit map of the supported encryption algorithms

0x01 - (Bit-0) AES128 support
0x02 - (Bit-1) to be defined

Number of Units:

This field is encoded to represent the key exchange capabilities

0x01 - (Bit-0) default AES128 key, as defined in APPENDIX D
0x02 - (Bit-1) to be defined

Function Code 10 - Receive BufferSize

This capability indicates the maximum size single message the PD can receive.

Compliance Levels:

This field is the LSB of the buffer size

Number of Units:

This field is the MSB of the buffer size

Function Code 11 - Largest Combined Message Size

This capability indicates the maximum size multi-part message which the PD can handle.

Compliance Levels:

This field is the LSB of the combined buffer size

Number of Units:

This field is the MSB of the combined buffer size

Function Code 12 - Smart Card Support

This capability indicates whether the PD supports the transparent mode used for communicating directly with a smart card.

Compliance Levels:

0 - PD does not support transparent reader mode
1 - PD does support transparent reader mode

Number of Units:

unused, send 0x00

Function Code 13 - Readers

This capability indicates the number of credential reader devices present. Compliance levels are bit fields to be assigned as needed.

Compliance Levels:

0x01 - (Bit-0) 0X02 - (Bit-1)

Number of Units:

Number of readers

Function Code 14 – Biometrics

This capability indicates the ability of the reader to handle biometric input

Compliance Levels:

0 - No Biometric
1 – Fingerprint, Template 1
2 – Fingerprint, Template 2
3 – Iris, Template 1

Number of Units:

Number of readers