Open Supervised Device Protocol

Build and certify OSDP systems
with ease.

A full suite of hardware and software tools for engineering teams integrating Open Supervised Device Protocol — from bus capture and emulation to field deployment.

Explore productsLaunch Osprio View ↗Osprio DocsLibOSDP Docs ↗
osdp.dev — live bus capture
# Bus: /dev/ttyUSB0 @ 9600 baud# Secure channel: active (AES-128)────────────────────────────────────────0.301ERR CP → PD[1] POLL len=80.600CMD CP → PD[1] CAP len=8 CRC16✓0.601CMD CP → PD[1] POLL len=8 CRC16✓0.900RPL PD[1] → CP ACK len=8 CRC16✓0.901CMD CP → PD[1] POLL len=8 CRC16✓1.200RPL PD[1] → CP CCRYPT len=8 CRC16✓1.200RPL PD[1] → CP ACK len=8 CRC16✓1.500RPL PD[1] → CP ACK len=8 CRC16✓1.500CMD CP → PD[1] CAP len=8 CRC16✓──────────────────────────────────────── SOM: 0x53 Type: Reply (1) Addr: 1 Len: 8 Seq: 0 Payload: ACK Checksum: AABB ✓

Success: OSDP v2.2 Verified!
OSDPIEC 60839-11-5
Open SourceLibOSDP core
Secure ChannelWorks Out-of-the-box
CP & PDMode Support
RS-485Multi-Drop
Bare-metal & RTOSDesigned for Embedded
Rust, Go, PythonLanguage Bindings
What is OSDP

Modern access control,
on an open standard

OSDP — the Open Supervised Device Protocol — is the IEC 60839-11-5 standard for how access control panels talk to the readers, keypads, and controllers in the field. It is secure, bidirectional, and vendor-neutral: one open protocol for the whole bus.

For nearly forty years that bus spoke Wiegand — a one-way, unencrypted signaling scheme still wired into most card readers in service today. Its weaknesses are now well understood, and as encryption and line supervision become baseline security expectations, standards bodies and government procurement increasingly specify OSDP for new and upgraded installations. The changeover is gradual, but the direction is set.

CapabilityLegacy Wiegandincumbent · since the 1980sOSDPtoday's standard
CommunicationOne-way — reader to panel onlyBidirectional command and reply
Data securityUnencrypted — credentials sent in the clearAES-128 Secure Channel encryption
Line supervisionUnsupervised — a cut wire goes unnoticedContinuously supervised — tamper and line faults detected
Bus topologyPoint-to-point — one device per home runRS-485 multidrop — up to 126 devices on one bus
StandardizationProprietary, ~40-year-old wiring schemeOpen IEC 60839-11-5 standard — interoperable across vendors
scroll to compare →
Capabilities

What OSDP brings to the bus

Secure Channel

AES-128 encrypted, authenticated sessions keyed per device (SCBK) — credentials never travel in the clear.

RS-485 multidrop

A single twisted pair carries up to 126 peripheral devices over long cable runs, replacing dedicated home runs.

Supervision

The panel polls continuously, so tamper, line cuts, and lost devices surface immediately instead of going silent.

CP & PD roles

A Control Panel drives the bus while Peripheral Devices reply — a clear, deterministic communication model.

PD capabilities

Every peripheral advertises what it supports — readers, inputs, outputs, LEDs, and secure channel — so a panel can discover and adapt to each device.

File transfer support

Stream firmware images and other payloads to a device over the bus — the foundation for over-the-air updates in the field.

Open & interoperable

Published by SIA as IEC 60839-11-5, so readers and panels from different vendors work together on one bus.

More than card reads

Keypads, LEDs, buzzers, biometrics, and output control — OSDP carries far more than a single credential number.

Why Osprio

OSDP is powerful.
Osprio makes it visible, testable, certifiable, and deployable.

OSDP is an open standard, but working with it has always meant bespoke scripts, borrowed lab gear, and a lot of guesswork about what's really on the wire. Osprio replaces all of that with four focused workspaces — capture the bus, emulate any device, qualify against the spec, and provision in the field. Each one takes a part of the protocol that's traditionally slow and error-prone and turns it into a repeatable, shareable workflow you can trust all the way from the bench to the field.

01

Visible

Capture live OSDP traffic and decode every command and reply as it happens. The Capture workspace shows you exactly what's on the wire.

02

Testable

Stand in as a CP or PD in software, automate card swipes, and inject faults. The Emulator workspace validates edge cases before hardware exists.

03

Certifiable

Drive a structured conformance plan against a PD. The Conformance workspace produces a detailed, repeatable compliance report.

04

Deployable

Commission PDs on site — set address and baud, then key the secure channel. The Provisioner workspace gets devices live in the field.

Why dedicated hardware

A USB-to-RS-485 converter won't cut it.

A converter is a dumb pipe: it dumps raw bytes onto USB and walks away, leaving your host to bit-bang frames, mind microsecond timers, and babysit the bus. OSDP is a hard real-time protocol — getting it right means owning the bus, not borrowing it. Osprio is a dedicated layer with one responsibility: speak OSDP correctly and hand your application clean, high-level events, so every part of your stack stays cleanly separated and your host CPU stays free for the logic that actually matters.

01

One job, done well

A converter forces your host to juggle framing, timers, and bus arbitration on top of its real work. Osprio owns the OSDP layer end to end, so each part of your stack keeps a single, clean responsibility.

02

Real-time bus timing

OSDP lives and dies by inter-character gaps and turnaround windows measured in microseconds. A dedicated MCU meets them deterministically — host USB scheduling and OS jitter never could.

03

Hardware packet detection

At high baud rates the start of a frame flies past in microseconds. Osprio detects packet boundaries in hardware, so nothing is missed or misframed even when the bus is saturated.

04

Distilled, high-level events

Instead of a firehose of raw bytes, Osprio hands your host decoded, validated events. Your CPU spends its cycles on business logic, not on parsing and CRC-checking every frame.

05

Identical on every host

Because the protocol runs on the device, behavior is the same across Windows, macOS and Linux — and even phones and tablets that could never bit-bang RS-485 timing themselves. No driver quirks, no per-OS USB latency to chase.

06

A proper RS-485 line

Correct biasing, termination, fail-safe and ESD protection keep the bus reliable and shield your host from faults — the electrical details a bare dongle leaves to chance.

Products

The Osprio product line

Professional OSDP workflows, from bench to field

Two hardware platforms sit underneath one universal software product, with workspaces nested inside that software layer.

Hardware
OsprioMiniRoad Testing

The compact OSDP bench companion

Compact host-powered hardware for running one Osprio View workspace at a time over USB-C and RS-485.

One workspaceUSB-CRS-485Field upgrades
Learn more →
OsprioProActive Development

The field-carry OSDP workstation

Battery-backed field hardware for running every Osprio View workspace, offline jobs, Bluetooth sessions, and secure provisioning flows.

Multi-workspaceBluetoothOffline modeSecure element
Learn more →

Weighing the options? Compare the hardware platforms →

Software
Osprio View - Capture WorkspaceLive

See the bus. Decode the truth

The OSDP protocol analyzer and bus sniffer: watch live OSDP traffic on the wire, decode every command and reply, and reopen saved captures offline.

Protocol analyzerSecure channelOffline replay
Explore the OSDP protocol analyzer →
Osprio View - Emulator WorkspaceLive

Test the device you have against the device you need

The OSDP emulator: stand in as a CP or PD on the bus, send commands and events from the UI, and automate them with reusable action cards.

CP + PD rolesFault injectionScripted flows
Explore the OSDP emulator →
Osprio View - Provisioner WorkspaceLive

Secure-channel commissioning without the field pain

The OSDP provisioning and commissioning tool: set address and baud, then key the SCBK in install mode — live one at a time or as a batch.

Address + baudSCBK keyingInstall mode
Explore the OSDP provisioning tool →
Osprio View - Conformance WorkspaceComing Soon

Compliance claims become repeatable evidence

OSDP conformance testing: drive a structured conformance plan against a PD and take away a detailed, repeatable compliance report.

Semi-automatedCommand coverageCompliance report
Explore OSDP conformance testing →

Weighing the options? Compare the software plans →

Open Source Core

Built on LibOSDP — the most popular OSDP implementation

Every Osprio product is built on top of LibOSDP, a battle-tested open-source library that handles the full SIA OSDP v2.2 protocol surface — secure channel, file transfer, multi-drop, and more.

  • Full CP and PD mode support
  • Secure channel with AES-128 and key management
  • OSDP file transfer (FT) for OTA firmware
  • Runs on Linux, RTOS, and bare-metal targets
  • Non-blocking, event-driven architecture
GitHub ↗libosdp guide ↗
osdp_cp_setup.c
#include <osdp.h>

osdp_pd_info_t pd_info[] = {
    { .address = 1, .baud_rate = 9600 }
};

int command_handler(void *data, int pd_idx,
                    struct osdp_cmd *cmd) {
    // react to PD commands here
    return 0;
}

int main() {
    osdp_t *ctx = osdp_cp_setup(1, pd_info);
    osdp_cp_set_command_callback(ctx, command_handler, NULL);
    while (1) {
        osdp_cp_refresh(ctx);
    }
}
Professional Services

Built by OSDP experts. Integrated into your product.

From bare-metal firmware porting to architecture reviews, our consulting services bring our OSDP expertise directly into your products.

01

Firmware & RTOS Integration

Porting LibOSDP to bare-metal, FreeRTOS, Zephyr, or custom embedded Linux with tight memory and timing budgets.

  • Board bring-up and transport layer adaptation
  • Deterministic timing and memory optimisation
  • Production-ready integration handoff
Learn more →
02

Custom Feature Development

Vendor-specific commands, secure-channel extensions, and interoperability hardening for production edge cases.

  • Proprietary command set design
  • Secure channel hardening and key rotation
  • Cross-vendor interoperability testing
Learn more →
03

Architecture Advising

Hands-on review of your OSDP system design before it solidifies — cheaper to fix on paper than in silicon.

  • CP/PD topology and reliability strategy
  • Rollout and provisioning playbooks
  • Team enablement sessions
Learn more →
04

Zephyr SDK for OSDP

A ready-to-ship Zephyr SDK with LibOSDP integrated and a dedicated OSDP driver layer — skip months of setup work.

  • Latest LibOSDP pre-integrated
  • Custom OSDP driver layer included
  • Accelerated PD firmware development
Learn more →