Showing posts with label RS-485. Show all posts
Showing posts with label RS-485. Show all posts

Thursday, October 10, 2019

OSDP an Access Control Protocol by SIA

OSDP an Access Control Protocol by SIA

ACCESS CONTROL WIEGAND PROTOCOL

In access control world we used Wiegand Protocol (Invented by John Wiegand in 1970). The communication protocol used in the Wiegand interface is called the Wiegand protocol. This protocol talks reader to controller. Basically Wiegand interface is a wiring standard used for interconnecting peripherals like fingerprint readers, card swipers or iris recognition devices. Initially created by HID Corporation, the Wiegand devices gained popularity thanks to the popularity of the Wiegand effect card readers of the 1980s. The Wiegand interface is considered a de facto wiring standard for card swipe mechanisms, especially for electronic data entry. Wiegand devices were originally developed by HID Corporation.
The Wiegand interface consists of three wires in the physical layer, the first wire is for ground and other two for data transmission, known as Data low/DATA0 and Data high/DATA1. The wires are composed of an alloy with magnetic properties. DATA0 and DATA1 are pulled up to high voltage, when no data is sent. When "0" is transmitted, the DATA0 wire is pulled to a low voltage while the DATA1 stays at high voltage. When "1" is transmitted, DATA0 stays at high voltage, whereas the DATA1 is pulled to a low voltage.

The most popular Wiegand interface is 26. It could be 3 bytes (Wiegand-26), 5 bytes (Wiegand-42) and even 7 bytes. Cable runs are limited to 500 feet. The Wiegand interface is unidirectional. It means that data is transferred in one direction only: from reader to the access panel. So access panel waits for a code on the line. If code is absent it means that there is no card near the reader or the reader is dead or the line is corrupted. To solve this problem in this way I asked one vendor to make a new firmware for its reader and now it sends each half an hour a "heart beat" code.
Given such limitations it has become increasingly clear that for reader technology and capabilities to progress, a bi-directional connection between the reader and access control system is a necessity. Some access control and reader manufacturers have recognized this need and developed proprietary bidirectional solutions. The OSDP a nonpriority interface specification that can be implemented without restriction. The protocol was originally developed by HID Global and Mercury Security Corp. in 2008 and adopted by SIA as a standard in 2011. SIA formed OSDP working groups, open to all members, and subsequent contributions have been provided by those participants.

What is OSDP
Open Supervised Device Protocol (OSDP) is an access control communications standard developed by the Security Industry Association (SIA) to improve interoperability among access control and security products. OSDP v2.1.7 is currently in-process to become a standard recognized by the American National Standards Institute (ANSI), and OSDP is in constant refinement to retain its industry-leading position. Open Supervised Device Protocol (OSDP) v.2.1.7 is a communications protocol that allows peripheral devices such as card readers and biometric readers to interface with control panels or other security management systems. It adds sophistication and security benefits through features such as bi-directional communication and read/write capabilities. The OSDP standard with Secure Channel Protocol (SCP) will support both IP communications and point-to-point serial interfaces, such as RS-485.

BI-DIRECTIONAL COMMUNICATION

The access control industry’s move to open standards is cultivating a broad range of interoperable products with enhanced features and security. Open standards also ensure that solutions can be easily upgraded to support changes in technology and applications, and give users the confidence that investments in today’s technologies can be leveraged in the future. OSDP with SCP specification provides bi-directional communications and security features for connecting card readers to control panels or other security management systems.
Bi-directional communication is particularly beneficial for enabling users to change configurations and to poll and query readers from a central system, which reduces costs while speeding, and simplifying configuration and improving the ability to service readers.

Unlike earlier unidirectional protocols, including the Wiegand interface and the clock-and-data signal approach used with magnetic stripe readers, OSDP enables continuous reader status monitoring. It can also immediately indicate a failed, missing or malfunctioning reader, as well as provide tamper detection and indication capabilities. All signaling is done over two data lines, providing the ability to use four-conductor cable to both power the reader and send and receive data. This lowers installation cost compared to the 6 to 10 conductors typically used for Wiegand.

HID Global is one of the first manufacturers to support OSDP with SCP in its reader portfolio as part of its iCLASS SE platform. iCLASS SE platform readers with OSDP enable central management, which lowers operational costs by making them faster and easier to configure and service.

SYSTEM INTEGRATION
OSDP gives Higher Security, Advanced Functionality, Ease of Use, More Interoperability. OSDP provides continuous monitoring of reader status, and can immediately indicate a failed, missing or malfunctioning reader. OSDP can also provide tamper indication for readers with onboard tamper detection capabilities. OSDP protocol for control panels to send messages for display to a cardholder via a screen embedded within or connected to the reader. The OSDP standard is particularly important for government installations because it supports high-end AES-128 encryption (required in federal government applications). And it meets the requirements of the Federal Identity, Credential and Access Management (FICAM) guidelines. OSDP also works with biometrics – Weigand does not.

SYSTEM ARCHITECHURE

Replacing legacy access control panels while maintaining operation with legacy card readers and other field devices.
When the need arises to replace or upgrade a card access or security control panel and if the new panel is OSDP compliant, it may be advantageous or necessary to convert the field devices to OSDP compatibility. This normally means replacing all readers, sensors, contacts, relays, and door control equipment to OSDP compliant versions as well. If this is not an immediate option due to time or cost constraints, the Cypress OSDP-1000 can provide an effective solution.

Credential Reader - Any Wiegand (Data 0 / Data 1), Strobed (Clock/Data), F/2F, or Serial interface can be handled by the OSDP-1000 when configured in "Reader Interface Mode". Since the format of the data is reported by the OSDP-1000 to the new control panel as an array of bits or characters, the panel's software must be configured to process the raw bit stream or character string. The reader type is configured by either on-board DIP switch or via OSDP configuration command from the panel.

Door Strike / Gate Operator - If the panel has provisions for multiple, dry-contact relay outputs and the panel's power supply is capable of driving the door or gate operator, then the 2 wires already in place to provide this function can continue to be used. Otherwise, since the OSDP-1000 is mounted in a secure location (not accessible from the un-secure side of the door or gate), it can be used to control the door or gate via OSDP command from control panel. If the control current is 1amp or less (at 12 to 24Vdc), the OSDP-1000's on-board, form C relay can be used. The new control panel will simply command the OSDP-1000 to turn the relay on or off. If higher currents are required, an external relay can be added. The power for the door strike, mag lock, or gate operator can be supplied from the panel (centralized power) or a local power supply near the door or gate (distributed power).
Sensors, Contacts, Switches, EOL Devices - Since the OSDP-1000 is mounted on the secure side of the door or gate, all remaining field wiring can be terminated at the OSDP1000. The new control panel will request data via protocol command/response and use it to determine the status of the door position switch, request-to-exit button, or motion detector. The OSDP-1000 has 2 Supervised alarm inputs to accomodate end-of-line resistor configurations. These can also be used as digital inputs.
Power Considerations - The OSDP-1000 does not magically create power for itself, the reader, or door strike from the twisted pair communication wires (but we might be working on it). The legacy panel or other power supply provided enough power to operate the reader, sensors, and door or gate operator. If the new control panel does not provide this power, then a suitable power supply must be installed at the panel location or at the door or gate. The OSDP-1000 only requires about 50ma and accepts a wide range of voltage (7 to 24Vdc). The reader, door strike, and any powered end-of-line device typically dictate what voltage to use (12 or 24Vdc).


All Devices - As mentioned earlier, converting all devices at the door or gate is recommended since this adds supervision of all signals. It also sets up the site for migration to an OSDP Control Panel in the future. Since the OSDP-1000 is mounted in a secure enclosure not vulnerable to tamper from the un-secure side of the door or gate, all signals can be terminated to it and supervised. The OSDP Reader has it's own polling address as does the second OSDP-1000 module configured for "Remote Interface Mode".
There still are many Weigand-base legacy systems in place and due to limited resources, it may take time to replace them all, but the migration is underway. Many organizations are taking a step-by-step approach replacing perimeter readers first and moving to interior readers as funding and time allow.


Future-proof your access control strategy today. Meet Signo, the signature line of access control readers from HID Global. This new reader line provides performance, versatility and security meet in a sleek, modern design. HID Signo™ Readers deliver mobile access capabilities, ensure easy migration from Wiegand to OSDP and support the widest range of credential technology so organizations can to upgrade at their own pace.

GROW YOUR BUSINESS
Integrators can differentiate from the competition by promoting open standard protocols, which can help build new customer relationships and win more projects by providing new found PACS features. With OSDP only four conductors are ever needed, two for power and two for all communication.
Wiegand does not allow for remote configuration or upgrade of a reader. OSDP enables a customer to remotely change the configuration of a reader (i.e. security keys or LED color) from any network-connected location.

BENEFITS OF OSDP
Compared to common low-security legacy protocols, the emerging OSDP standard offers:
Higher Security
·  OSDP is more secure than the most common access control communications protocol.
·     OSDP Secure Channel supports high-end AES-128 encryption (required in federal government applications).
·     OSDP constantly monitors wiring to protect against attack threats.
Advanced Functionality
·         Supports advance smartcard technology applications, including PKI/FICAM and biometrics.
·         Supports bi-directional communications among devices.
·         OSDP supports advanced user interface, including welcome messages and text prompts.
·         OSDP’s use of 2 wires instead of 12+ allows for multi-drop installation, supervised connections to indicate reader malfunctions, and scalability to connect more field devices.
Ease of Use
·         Audio-visual user feedback mechanisms provide a rich, user-centric access control environment.
·         Guesswork is eliminated since encryption and authentication are predefined.
·         Low cost of implementation on an embedded device.
More Interoperability
·         Using OSDP enables communication among different manufacturers' devices and solutions.
·         The standard applies to peripheral devices (PDs) such as card readers and other devices at secured access doors/gates and their control panels (CPs).
·         SIA promotes the standard at regular “plugfests” among manufacturers and at InteropFest – an annual interoperability event held at ISC West tradeshow every spring in Las Vegas, Nevada.
·         The OSDP specification is currently recommended when TCP/IP, USB, or other common protocols do not lend themselves to the application.
·         The OSDP specification is extensible to IP environments and the OSDP WG is working on deploying OSDP over IP soon.

Ref:
https://ipvm.com/reports/osdp-access