Didactum Knowledge Base · Didactum Devices
Monitoring System 300T
Overview of the device, connections, and technical specifications of the Didactum Monitoring System 300T – the DIN-rail monitoring and control unit with CAN bus expansion, 8 dry contact inputs, and optional LTE modem for industrial plants, control cabinets, and building automation.
What makes the 300T stand out
A compact DIN-rail solution for environmental monitoring and I/O control in industrial and electrical systems.
Built for the DIN rail
Specifically designed for mounting in control cabinets and industrial racks, and also suitable for wall mounting as an alternative.
4 analog ports + CAN bus
4 analog sensor ports directly on the device, expandable via CAN bus to up to 32 devices.
Real-time alerting
By email, SMS, SNMP trap, syslog, web-to-SMS, or push notification.
Web-based
Management via any browser as well as via SNMP, Modbus TCP/IP integration into existing monitoring systems.
I/O DIN controller
8 dry contact inputs and 2 relay outputs for controlling doors, fans, generators, UPS units, and circuit breakers.
Scalable
Up to 1000 elements – notifications, triggers, timers, logic schemes, and sensors.
Redundant power supply
12V DC main supply plus separate 12V and 24–48V DC backup inputs for maximum reliability.
LTE & expansion slot
Optional LTE modem as well as a retrofittable Modbus/RTU expansion for additional sensors and meters.
Made in the EU
Rugged plastic DIN-rail enclosure, German support included, regular firmware updates.
Typical use cases
- Environmental monitoring in control cabinets, distribution rooms, and industrial racks (temperature, humidity, voltage)
- I/O control of fans, generators, UPS systems, and circuit breakers via the dry contact inputs and outputs
- Leak detection under raised floors or on air conditioning and cooling systems
- Production halls and industrial plants: machine, fan, and voltage monitoring
- Access and door monitoring for server racks and equipment rooms
- Vibration monitoring to protect against sabotage or unauthorized access
- Remote monitoring of branch offices and remote sites, optionally via LTE modem
- Video surveillance via USB or IP camera combined with sensor alarms
Connections & Controls
All 17 ports, buttons, and slots on the 300T's housing, along with the complete wiring diagram, at a glance.
As a DIN-rail device, the 300T groups all connections on the front of its slim plastic enclosure: DIP switch, LTE modem and SD card slot, LAN, USB, CAN and analog sensor ports, reset button, 8 dry contact inputs, restart button, 2 relay outputs with status LEDs, system LEDs, and the staggered power inputs (24–48V backup, 12V backup, and 12V main supply).
Connection overview (1–17)
All connections and controls of the 300T in one view, numbered from 1 to 17.
DIP switch (N–R)
Normal mode (N): switch always set to the left. Recovery (R): switch set to the right, loads the clean system image from the SD card.
LTE modem slot
Slot for an optional, separately available LTE modem for remote monitoring without a fixed IP network.
SD card
MicroSD card slot with ejector – for data storage or system recovery.
LAN port
Ethernet 10/100 Base-T connection. Orange LED shows network traffic, green LED shows connection status (steady green = connected, blinking = connecting or system startup).
USB
USB Type-C port – for USB camera capture as well as USB flash drives for system logs and system recovery.
CAN
Digital RJ12 6P4C connection for CAN sensors, expansions, and devices on the CAN bus, cascadable. Green LED shows bus status – slow blinking: no connection, fast blinking: configuration in progress, steady light: connected to CAN devices.
Reset button (factory settings)
Hold for more than 5 seconds – the ERR LED starts blinking to indicate the recovery process has begun. After 20–60 seconds the device is reset and reachable again once the ACT LED blinks.
Analog sensors A1–A4
4× RJ12 6P4C connections for analog sensors with automatic detection (AutoSense).
Dry contact inputs 1–8
8 digital inputs, 3.5 mm pitch, 6-pin, for door, water, or other contact sensors.
Restart button
Hold for 2 seconds and release to restart the system.
Chassis ground
Increases immunity to conducted and radiated RF interference. Connection should be made by a qualified electrician.
Expansion slot
Housing for the optional Modbus/RTU expansion to connect additional Modbus sensors and meters.
Outputs 12V / 0.25A
Terminal blocks (electronic relay) for each output, 3.81 mm pitch, 3-pin, with individual status LEDs (E1/E2).
Status LEDs (ACT, ALARM, ERR)
ACT (green) shows system status (operation: 2 Hz blinking, successful update: 4 Hz blinking). ALARM is freely programmable via the interface. ERR (red) indicates errors and data traffic.
DC 24–48V backup power
Alternative power supply, 5.08 mm pitch, with voltage reserve for redundant operation.
DC 12V backup power
Alternative power supply, 12V DC / 2A, barrel connector (2 mm inner contact, 6.3 mm outer contact).
DC 12V power
Main power input, 12V DC / 2A, 3.81 mm pitch, 2-pin.
Wiring diagram
Complete wiring diagram of all ports, outputs, and expansion options of the 300T at a glance.
Dimensions in detail
Technical Specifications
Device management
| Device management | Web, SNMP |
|---|---|
| Sensor access | Three-tier login (user management) |
Interface
| LAN | Ethernet 10 / 100 Mbit |
|---|---|
| Operating system | Linux v.6.2 |
| Interface | Any browser |
| Memory (RAM) | 128 MB |
| CPU speed | 720 MHz |
| Total CPU cores | 2 |
| Clock | Built-in clock |
| Timer | Built-in watchdog |
| USB | 1× USB Type-C 2.0 |
Sensors & Logic
| Max. number of sensors | 100 (physical sensors, dry contacts, relays) |
|---|---|
| Max. number of elements | 1000 (notifications, triggers, timers, logic, sensors, etc.) |
| Virtual functions | Ping monitoring, SNMP GET, logic schemes, triggers, timers, virtual calculations (math element), up to 4 IP cameras |
Network / Protocol support
| LTE gateway mode | Yes, via optional LTE modem |
|---|---|
| LTE access mode | Yes, via optional LTE modem (incl. web-to-SMS) |
| Network protocols | DHCP, HTTP, HTTPS, SNMP (v1/v2c/v3), SMTP, FTP, Syslog, TLS, RADIUS, DynDNS |
| Modbus RTU | Optional, with OSDPv2 RS485 expansion module |
| Modbus TCP/IP | Yes |
| VPN (secure data transmission) | Supported (incl. OpenVPN/SSL) |
Notifications
| Alarm types | Email, FTP, Syslog, SMTP, SNMP traps, web-to-SMS, push |
|---|---|
| Max. email recipients | 20 |
| Max. SMS recipients | 20 |
Power supply
| Energy efficiency (EU Energy Level) | Grade A |
|---|---|
| Power input (230V AC) | No |
| Power input (24–48V DC) | Yes (backup input, 5.08 mm pitch) |
| Power input (12V DC) | Two inputs (main and backup supply) |
| Redundant power supply | DC/DC, with voltage reservation |
| Min. power consumption | 1 W |
| Max. power consumption | 10 W |
Inputs/Outputs
| Analog port | 4 built-in ports (RJ12 6P4C), expandable via CAN bus |
|---|---|
| CAN port | 1 port, up to 32 devices |
| Dry contact inputs | 8, 3.5 mm pitch, 6-pin |
| Relay outputs (240V / 10A) | No |
| Relay outputs (12V / 0.25A) | 2, 3.81 mm pitch, 3-pin |
Video support
| USB cameras | 1 |
|---|---|
| IP cameras | up to 4 (display only) |
Storage & Logs
| MicroSD slot | For data storage and system recovery |
|---|---|
| USB export | Logs, sensor data, settings |
| Log delivery | Syslog, FTP, email |
Environmental conditions
| Operating temperature | -10 to +70 °C |
|---|---|
| Storage temperature | -25 to +85 °C |
| Operating humidity | 0 to 90% (non-condensing) |
Mechanics & Housing
| Installation | DIN rail, alternatively wall mounting |
|---|---|
| Housing material | Plastic |
| Dimensions (L × W × H) | 212.5 × 90.1 × 32.2 mm |
| Weight | approx. 0.5 kg |
| Reset/recovery switch | Present |
Frequently Asked Questions
What is the Didactum Monitoring System 300T and what is it used for?
The Didactum Monitoring System 300T is a DIN-rail monitoring and control unit developed for industrial plants, electrical installations, and control cabinets. It monitors environmental parameters such as temperature, humidity, voltage, leaks, smoke, and vibration, while also functioning as an I/O DIN controller for controlling doors, fans, generators, UPS systems, and circuit breakers.
Which sensors can be connected to the system?
The Monitoring System 300T has 4 analog sensor ports directly on the device as well as 8 dry contact inputs, and can be expanded via the CAN bus with up to 32 additional devices – including temperature, humidity, smoke, PIR motion, door, vibration, water, and voltage sensors. In total, up to 100 physical sensors, contacts, and relays can be managed simultaneously.
How does the 300T differ from other Didactum monitoring systems such as the 100T?
While the Monitoring System 100T is designed as a desktop device in a metal enclosure for server rooms, the 300T was specifically developed for DIN-rail mounting in control cabinets and industrial installations. It also adds 8 dry contact inputs instead of 4, along with staggered 12V and 24–48V DC power inputs for redundant power supply, but comes in a lighter plastic enclosure instead.
How are alarms and notifications sent?
The system offers various alerting methods: email notifications to up to 20 recipients, SMS or web-to-SMS (optional via LTE modem), SNMP traps for network management systems, syslog messages, FTP transfer, and push notifications. In addition, external sirens or beacon lights can be connected via the relay outputs.
Can the system be integrated into existing IT and automation infrastructures?
Yes. The system supports SNMP v1/v2c/v3, Modbus TCP/IP, and, via the optional VT485m expansion, Modbus RTU, and can be integrated into common monitoring platforms such as Nagios, PRTG, Zabbix, or Check_MK. It connects via Ethernet and can be managed both through the web interface and via network management tools.
What do the LTE modem and expansion slots do?
The LTE modem slot accommodates an optional, separately available LTE modem, enabling remote monitoring and the sending of alarm messages even without a fixed IP network. The expansion slot accommodates the optional Modbus/RTU expansion, which allows additional Modbus sensors and meters to be connected.
What power supply does the system require and how fail-safe is it?
The Monitoring System 300T is powered via a 12V DC main input and also has two separate backup power inputs – 12V DC and 24–48V DC – for a redundant power supply with voltage reservation. A built-in watchdog ensures automatic restarts in the event of system errors, and all events are logged and can be exported via syslog, FTP, or email.
Questions about the 300T?
Our support team in Germany provides free advice on selection, setup, and sensors.
Scope of delivery
- 1 x Didactum 300T monitoring device
- 1 x DIN rail holder
- 1 x RJ-45 3m power cable
- 1 x OTG USB cable
- 1 x Terminal 10P adapter, 3.81 mm
- 2 x Terminal 6P adapter, 3.50 mm
- 1 x Terminal 3P adapter, 3.50 mm
- 1 x Terminal 3P adapter, 3.81 mm
- 1 x Terminal adapter, 5.08 mm
- 1 x Power supply 12 VDC 1A, 5.5 x 2.1 mm
- 1 x Quick start guide
Manufacturer information:
Didactum® Security GmbH
Im Mühlenfeld 4
48163 Münster
Germany
Phone: +49 - 171 - 33 11 577
Email: info@didactum-security.de
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