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What can be better than OSDP?

What can be better than OSDP?

How do you think, what level of security your office or production facility is at? Are your key cards and your corporate access secure? What if I say that most modern security systems are even easier to break than a regular door lock?

Despite the existing problems of ensuring the safety of information, progress does not stand still, including the development of security technologies. But there is one global problem - it is going very slowly. For example, although the Wiegand interface is used almost everywhere now and it provides the ability to work with protected data on Mifare cards, many continue to use EM Marine cards due to their cheapness and availability.

This approach can be explained when used at small facilities, but a similar situation exists in many large enterprises, where security is not just a formality. And if we look deeper?

Wiegand was developed over 25 years ago and at the same time has certain shortcomings and limitations, it does not meet many requirements of modern technologies in terms of security.

Wiegand allows to use Mifare cards in protected mode instead of reading the standard UID, but this is still not the best option. There is an alternative option on the market - the OSDP interface, which, although slowly, is now gaining popularity.


OSDP (Open Supervised Device Protocol) is an open bi-directional protocol that can be modified and expanded with additional functions. OSDP was developed by the SIA, and continues to develop through the efforts of the companies that are members of this organization.

What is happening now? The Wiegand standard cannot ensure the security of today's enterprise organizations fully, and OSDP is still a long way from global integration. In this regard, companies constantly face threats that create problems to ensure comprehensive security of data transmission.

The use of OSDP, especially at facilities with increased security requirements, is a necessity today. Ease of installation, two-way communication with readers, simplicity of hardware configuration, the use of cryptography to protect data - all these factors contribute to optimizing work, saving money and improving the security of objects.

Function Wiegand OSDP
no yes
Traffic encryption no yes
Expansion of
no possibly
Line range up to 150 meters up to 1200 meters
Cost of cabling high installation costs average installation cost
Indication control limited control of indication flexible configuration with a wide range of possibilities, including text displays
Readers’ monitoring monitoring and configuration of readers is not supported constant monitoring and the possibility of flexible and centralized configuration of readers


The physical basis of the OSDP protocol is the RS-485 interface, which in some implementations allows to connect more than 100 devices per interface line. If the device does not need additional power, then only one twisted pair is sufficient for connection.

Example of connecting devices to the RS-485 interface

An illustrative example of OSDP features is the ability to connect multiple readers in one line. It is convenient and economical, as you do not need to occupy separate ports on the controller and spend energy and resources on laying cables for each of the readers. But this scheme also has its drawbacks: as it is a serial connection, when the circuit is broken, the entire bus will cease to function completely after the break point.

OSDP adopts a standard byte transfer format: 8-N-1 at 9600 baud. This option is quite slow and can impose its own limitations, but at distances of about 1 km you can set it to work at a speed of 57600 baud, and at shorter distances - even higher.

interesting facts: indication

Now let's speak about the pleasant bonuses, specifically about the sound and light indication of readers. It also has its advantages over Wiegand. Bidirectional OSDP allows not only transmitting data from the reader to the controller, but also receiving feedback from the reader, as well as controlling its indication without increasing the number of control inputs.

When using Wiegand, several additional lines are used to control the indication. In turn, within the framework of the OSDP protocol, both data about the card and a command to control the indication are transmitted over one wire. It is also possible to connect LCD displays to show text messages on them.

Thus, the advantage of OSDP lies not only in significant expanding the functionality, but also in simplifying the setup procedure and saving the cable during connection.

What can be better than OSDP

OSDP is a protocol that is open to all vendors. It allows to make custom modifications and has the ability to expand with additional functions.

Sigur has improved the standard protocol by developing its own version - SSDP (Sigur Supervised Device Protocol). SSDP is a convenient and intuitive interface for quick integration and work with ACS without restrictions.

Advantages of SSDP:

  • Updating encryption keys on readers directly from the server (for example, when centralized configuration during commissioning or when changing encryption keys promptly if they are compromised);
  • Centralized and remote change of the reader's operating parameters (for example, changing the BLE operating mode);
  • Centralized firmware's update for end devices;
  • Centralized monitoring of the reader's status: receiving data on supply voltage, temperature, firmware version, current reader's settings;
  •  Flexible, easy-to-use and understandable indication with a large number of settings - the system is as clear and predictable as possible. Depending on the event of the system, the controller issues an appropriate command to the reader, which, in turn, provides the employee with explicit feedback.

It is planned to support the development of the SSDP protocol by optimizing existing functions and adding new ones in the future.

SSDP is a tool that allows to solve remotely most of the emerging problems in access control and management systems. And, just as important, it facilitates quick troubleshooting. For example, by monitoring the state of the reader, it determines where its malfunction is, minimizing user's participation.

The benefits of switching to SSDP are for everyone. The end user will be able to save money on the purchase of basic and peripheral equipment, while receiving more functionality for daily use and settings. For representatives of installation organizations, the use of SSDP means a decrease in the number of wires and simplification of the equipment installation process: there is no need to bypass each reader physically, which there can be very many at one site, with a master card for reprogramming. Flexible adjustment of the indication allows to identify the essence of the problem quickly and, accordingly, also find ways to solve it quickly.


Many users are switching to OSDP gradually, which will inevitably become widespread on the security market. In order for this to happen faster, active participation of representatives of this sphere is necessary, namely: manufacturers who will highlight new opportunities and system integrators who will broadcast this information to end customers in an understandable, well-reasoned language.

The standardization of the OSDP protocol obliges manufacturers of access control systems to follow certain rules. It excludes the concept of Vendor Lock, when the equipment of one vendor works only as part of his own system. In the case of OSDP, you can use a controller from one manufacturer and the reader from another. However, this framework of the standard is not so strict, which provides a significant range of opportunities for manufacturers to develop and compete with each other by implementing interesting logics based on an extension of the standard protocol, which Sigur experts did by developing their own SSDP protocol.