Didactum Knowledge Base · Didactum Devices
Monitoring System 550T
Overview of the device, connections, and technical specifications of the Didactum Monitoring System 550T – the 19" rack solution for monitoring multiple racks, building management systems, and production environments.
What makes the 550T stand out
The 19" rack solution for monitoring multiple racks, data centers, and building management systems.
Up to 1000 Elements
Sensors, notifications, triggers, timers, and logic schemes in one system.
8 Analog Sensor Ports
For temperature, humidity, airflow, and other environmental parameters.
Flexible Alerting
SNMP trap, email, and optional SMS/call with an installed mobile modem.
Web-Based & SNMP
Integration with Nagios, CheckMK, or Zabbix, and custom solutions via the Web API.
I/O Control
Control of doors, fans, generators, UPS units, and circuit breakers.
Redundant Power Supply
Up to two independent power inputs (AC or DC) plus optional battery backup.
Modbus-Capable
Optional RTU expansion for up to 32 Modbus devices, daisy-chain up to 1000 m.
Made in the EU
German support included, with regular firmware updates.
Typical Use Cases
- Monitoring multiple racks in data centers and server rooms
- Collecting measurements from building management systems (BMS)
- Production monitoring with Modbus sensors and measuring devices
- Protecting sensitive data in financial institutions and cloud environments
- Automated control of cooling systems and access doors
- Disaster prevention in the event of smoke or water leaks
- Energy efficiency optimization through airflow and temperature data
- Remote monitoring of distributed sites via LTE modem
Connections & Controls
All ports, buttons, and LEDs on the front and rear of the 550T at a glance.
Front View – Connections 1–11
Front view: 19" mounting brackets, analog sensors, LAN, modem slot, CAN, USB, status LEDs.
19" Mounting Brackets
2× mounting brackets for installation in a 19" 1U rack slot.
Label Field
Free space for a label, e.g. to mark the device's IP address.
Analog Sensors A1–A8
8× RJ12 ports for analog sensors with automatic detection (AutoSense).
LAN Port
Ethernet 10/100/1000 Base-T with orange LED (network traffic) and green LED (link status, blinks during startup or connection setup, stays lit continuously when a connection is established).
Modem Slot
For the optional LTE module "VT740" – ordered separately.
CAN 1 / CAN 0
2× RJ12 ports for CAN sensors, expansions, and devices, chainable via daisy-chain. CAN status LED (green): slow blinking = nothing connected, fast blinking = configuration in progress, solid = devices connected.
USB
Micro-USB port – for USB camera recording, USB flash drive for system logs, and system recovery.
Restart Button
Hold for 2 seconds to restart the device.
Status LEDs ACT / ERR / ALARM
ACT (green): system status, blinks 2×/sec during normal operation, 4×/sec on a successful update. ERR (red): off during normal operation, solid on error, blinks 2×/sec during an update. ALARM: freely programmable via the interface.
Temperature Sensor
Built-in sensor, accuracy ±1 °C.
Status LEDs E1, E2 / R1, R2
E1/E2 indicate the status of the two 12V/0.25A outputs, R1/R2 indicate the status of the two NC/NO/COM relays.
Rear View – Connections 12–26
Rear view: dry contacts, relays, power supply, expansion slot, reset, DIP switch, SD card.
Dry Contact Inputs 1–32
Digital input terminals (type IN) for monitoring potential-free contacts.
Isolated Dry Contact Outputs 1–8
24V DC / 15 mA output terminals (type OUT).
Battery Expansion Slot
For an optional battery backup "VT-ACCU" (rechargeable) or "VT-BAT" (9V block) – only one of the two at a time, sold separately.
RESERVE (Power Input)
Reserve power input 100–240V AC, 50/60 Hz, 2A fuse (5×20 mm), type C14 – depending on the ordered variant.
MAIN (Power Input)
Main power input 100–240V AC, 50/60 Hz, 2A fuse (5×20 mm), type C14.
Relay 1, Relay 2
NC/NO/COM power relay terminals. Orange LED on = relay active, off = relay inactive (default state configurable).
12V 0.25A Outputs
Output terminals (electronic relay), status LEDs on the front panel (item 11).
Reset Button (Factory Defaults)
Hold for more than 5 seconds – the ERR LED begins to blink; after 20–60 seconds the device is reset and reachable again, indicated by the ACT LED.
DIP Switch N/R
"N" normal operation (default position, always to the left). "R" loads a clean system image from the SD card for full system recovery.
SD Card
MicroSD card slot with ejector – for data storage or system recovery.
Expansion Slot
For "VT485m" (Modbus/RTU expansion) or "VT485r" (OSDPv2 reader expansion) – only one of the two expansions at a time, sold separately.
DC 12V Backup Power
Third, independent backup power line for the main board.
Chassis Ground
Grounding connection, M4 thread – improves immunity against conducted and radiated RF interference. Connection by a qualified electrician recommended.
RESERVE INPUT 24–48V
Reserve power input 24–48V DC, 5.08 mm connector, 18–72V DC to 12V DC/0.84A – depending on the ordered variant.
MAIN INPUT 24–48V DC
Optional main power input for DC order variants.
Connection Diagram – Full Overview
Full overview of all connections on the front and rear panels in a single diagram.
What's Included
Please check the delivery contents for completeness upon receipt and report any missing or damaged parts to your supplier immediately.
- Didactum 550T Monitoring Device1 piece
- OTG USB-C Cable1 piece
- UTP Ethernet Cable, 3 m1 piece
- Micro-USB-C OTG Adapter Cable1 piece
- 19" Rack Brackets2 pieces
- M3×8mm Phillips Flat-Head Screws6 pieces
- Connection Terminal, 6-pin, 5.08 mm1 piece
- Connection Terminal, 3-pin, 3.81 mm1 piece
- Connection Terminal, 6-pin, 3.5 mm8 pieces
- Connection Terminal, 8-pin, 3.5 mm2 pieces
- Connection Terminal, 2-pin, 3.81 mm1 piece
- Connection Terminal, 2-pin, 5.08 mm1 piece
- EU Schuko Cable (C13, 0.75 mm², 230V, 10A)1 piece
- IEC Cable (C13/C14, 230V, 10A)2 pieces
- Self-Adhesive Rubber Feet4 pieces
- Quick Start Guide1 piece
Dimensions in Detail
Technical Specifications
Device Management
| Device Management | Web, SNMP |
|---|---|
| Sensor Access | Three-tier login |
Interface
| LAN | Ethernet 100 Mbit |
|---|---|
| Operating System | Linux v.6.2 |
| Interface | Any browser |
| Memory (RAM) | 128 MB |
| CPU Speed | 1 GHz |
| Total CPU Cores | 2 |
| Clock | Built-in clock |
| Timer | Built-in watchdog |
Sensors & Logic
| Max. Number of Sensors | 150 (physical sensors, dry contacts, relays) |
|---|---|
| Max. Number of Elements | 1000 (notifications, triggers, timers, logic, sensors, etc.) |
Network / Protocol Support
| LTE Gateway Mode | Optional, with LTE modem module |
|---|---|
| LTE Access Mode | Optional, with LTE modem module |
| Network Protocols | DHCP, HTTP, HTTPS, SNMP, SMTP, FTP, Syslog, TLS |
| Modbus RTU | Optional, with OSDPv2 RS485 expansion module |
| Modbus TCP/IP | Yes |
| VPN (secure data transmission) | Yes |
Power Supply
| Energy Efficiency (EU Energy Level) | Grade A |
|---|---|
| Power Input (230V AC) | Two inputs |
| Power Input (24–48V DC) | Two inputs |
| Power Input (12V DC) | One input |
| Min. Power Consumption | 1 W |
| Max. Power Consumption | 10 W |
Inputs/Outputs
| Analog Port | 8 built-in ports (6P6C for connecting analog sensors) |
|---|---|
| CAN Port | 2 ports, max. 32 devices per port |
| Dry Contact Inputs | 32 |
| Relay Outputs (240V / 10A) | 2 |
| Relay Outputs (12V / 0.25A) | 2 |
Video Support
| USB Cameras | 1 |
|---|---|
| IP Cameras | up to 4 |
Environmental Conditions
| Operating Temperature | -10 to +70 °C |
|---|---|
| Storage Temperature | -25 to +85 °C |
| Operating Humidity | 0 to 90% (non-condensing) |
Mechanics & Enclosure
| Installation | 19" 1U |
|---|---|
| Enclosure Material | Sheet steel |
| Dimensions (L × W × H) | 440 × 44 × 90 mm |
| Weight | 1.6 kg |
Frequently Asked Questions
What is the Didactum Monitoring System 550T and what is it used for?
The Didactum Monitoring System 550T is a standalone 19" 1U monitoring and control unit for data centers, multiple racks, server rooms, and building management systems. It monitors environmental parameters such as temperature, humidity, voltage, leakage, smoke, and airflow, while also functioning as an I/O controller for doors, fans, generators, UPS systems, and circuit breakers – all without an external server or additional software.
What power supply variants are available and how do they differ?
The 550T is available in five variants: with a single 230V AC input, a redundant 230V AC input (2×), a single 24–48V DC input, a redundant 24–48V DC input (2×), and a hybrid variant with 230V AC + 24–48V DC. For redundant variants, the device automatically selects the line with the highest applied voltage; if one line fails, the remaining line takes over the supply without interruption. Optional battery backup can also be added as a third, independent level of protection.
What sensors can be connected to the system?
The 8 analog sensor ports and the two CAN bus ports support numerous Didactum sensors – including for temperature, humidity, smoke, water/leakage, vibration, door and window contacts, motion detectors, and current and voltage sensors. CAN expansion units can be used to further increase the number of sensors.
How does the 550T differ from the smaller Didactum systems (100T, 300T)?
The 550T offers significantly more capacity (up to 150 sensors, 1000 system elements) and more connections (8 analog ports, 2 CAN ports, 32 dry contacts, isolated dry contact outputs) than the more compact 100T and 300T models. It is also designed in a 19" 1U format for rack mounting and supports redundant or hybrid power supply – ideal for data centers with multiple racks rather than single smaller rooms.
How are alerts and notifications sent?
Notifications are sent via email, SNMP trap, syslog, FTP log, and web-to-SMS. With an LTE modem installed, SMS and voice calls are also possible. Alert thresholds, escalation levels, and recipients can be individually configured in the web interface.
Can the system be integrated into existing IT infrastructure?
Yes. The 550T supports SNMP v1/v2c/v3, Modbus TCP/IP (with an expansion, also Modbus RTU), and a Web API, allowing seamless integration into network management systems such as Nagios, CheckMK, or Zabbix.
What do the expansion and battery slots do?
The expansion slot accepts either the Modbus/RTU expansion or the OSDPv2 reader expansion (each sold separately, only one of the two at a time). The battery slot allows a rechargeable battery backup to be added as an additional, independent power reserve in case all power inputs fail.
Questions about the 550T?
Our support team in Germany provides free advice on selection, power supply, and setup.
Scope of delivery
- 1 x Didactum 550T monitoring device
- 1 x OTG USB-C cable
- 1 x UTP 3m Ethernet cable
- 1 x Micro USB-C OTG adapter cable
- 2 x 19" rack mounts
- 6 x M3 x 8mm Phillips flat head screws
- 1 x terminal 6P 5, 08mm
- 1 x terminal 3P 3.81 mm
- 8 x terminal 6P 3.5 mm
- 2 x terminal 8P 3.5 mm
- 1 x terminal 2P 3.81 mm
- 1 x terminal 2P 5.08 mm
- 1 x EU Schuko C13 0.75 мм2 . 230V 10A cable
- 2 x IEC C13/C14 230V 10A cable
- 4 x self-adhesive rubber feet
- 1 x quick start guide
Manufacturer information:
Didactum® Security GmbH
Im Mühlenfeld 4
48163 Münster
Germany
Phone: (+49) 2501 92 90 160
Email: info@didactum-security.de
