Access Control

Access_Control Proposal for the new virtual device: access request

General
As Access request device are all devices named, which deliver similar data information and do not need interaction. Part of that devices are e. g.:
 * RFID reader (transponder cards)
 * Chip card, smart card
 * Barcode reader
 * Fingerprint sensor
 * Voice detector

This devices can read different media. Every media is assigned one channel or every transponder type is assigned one channel.

There are two kinds of operating modes:


 * 1) Continuous reading: It is tried to search for a media continuously. If there is one found this event is signalized with a PDO and the data is provided in the data object. At the same time the timer for the upload timeout is running. At this time the searching for a media is stopped. After releasing the data object the searching is started again.
 * 2) One time read: It is only tried to search for a media only one times. The upload timeout does not have any meaning at this mode (the timeout is infinite).

The processing of the data from the device is not part of the specification (e. g. data base, signals to lift controller).

Message from device (PDO - same like a virtual input)
Upload request: Device has detected media (e. g. transponder card found):

Upload-Timeout has expired or data object was cleared:

Messages to device (PDO - same like virtual output)
Upload acknowledgement:

Data:

With a set acknowledge bit the data object is cleared.

Property:

Device Configuration
Object description

Entry description

Value definition

An upload timeout of zero means timer disabled. The timer is only used in continuous mode.

Channel Type ID
Object description

Entry description

Value definition

Main Type definition

Sub Type definition if Main Type = 1 (RFID)

Features

Optional

Manufacture specific

Channel Type Info
Object description

Entry description

Channel Activation And Commands
Object description

Entry description

Value definition

Channel Data
Object description

Entry description

Value definition

Is there no data available the length of the object is zero.

The object is cleared when:

- the acknowledge bit in the upload acknowledgement PDO is set, or - the channel is deactivated, or - the upload timeout is expired, or - in the channel command bit 2 is set

Channel Data Read/Write Start Address (optional)
Object description

Entry description

Value definition

With this object an offset in bytes to the beginning of the data can be set for reading or writing.

Channel Data Read/Write Length (optional)
Object description

Entry description

Value definition

With this object the length in bytes can be set for reading or writing the data object.

A data read/write length value of zero means all available bytes.

The first proposal of RSbySCHAEFER could be found here:

Access_Control_(RSbySCHAEFER-2009)