Prerequisites

Didactum monitoring devices are specialized rack monitoring units that provide environmental parameters such as temperature, humidity, voltage, leakage, and door contacts via SNMP. This guide describes the complete integration into Paessler PRTG Network Monitor.

Required:

• PRTG Network Monitor (version 22.x or newer) with administrator access
• Didactum monitoring device (e.g. rack monitoring) reachable on the network
• SNMP enabled on the Didactum device (default: SNMP v2c)
• Network communication: UDP port 161 (SNMP) enabled from the PRTG probe to the Didactum device
• SNMP community string known (default: public)
• MIB file of the Didactum device (available from the manufacturer or retrievable from the device)

1. Access web interface: Open a browser and enter the IP address of the Didactum device (e.g. 192.168.1.100). Default login: admin / admin.
2. Open network/SNMP settings: Navigation: Settings → Network → SNMP (or: Settings → Network → SNMP)
3. Enable and configure SNMP:
   • SNMP enabled: Yes / Enable
   • SNMP version: v2c (recommended) or v3 for enhanced security
   • Community string (v2c): public (or custom string, e.g. didactum_monitor)
   • SNMP port: 161 (default, UDP)
   • Allowed Managers: enter the IP address of the PRTG server (security)
4. Configure trap receiver (optional): SNMP trap receiver: IP of the PRTG server, port 162 (UDP). This enables proactive alarm notifications from the device to PRTG.
5. Save settings and restart the device if necessary. On some models, a restart is required for SNMP to become active.

Note: SNMP v3 provides authentication and encryption. Recommended for production environments. Protocol: SHA, encryption: AES128.

Warning: Be sure to change the default community string public in production environments to prevent unauthorized SNMP access.

Before configuring PRTG, test SNMP connectivity from the PRTG probe server:

# On Linux / from a Linux system:

snmpwalk -v2c -c public 192.168.1.100
 
# Query a specific OID (system description):

snmpget -v2c -c public 192.168.1.100 1.3.6.1.2.1.1.1.0
 
Windows: Use the built-in PRTG SNMP tester:

On the Paessler website:

Setup → Downloads → PRTG Tools → SNMP Tester

By importing the Didactum MIB file, PRTG can automatically translate OID numbers into readable names and enables the convenient SNMP MIB Import sensor.

3.1 Obtain MIB file

• Direct download from the device: <DEVICE-IP>/mib/ (if available)
• Typical file name: DIDACTUM.mib

3.2 Import MIB file into PRTG

1. Copy the MIB file to the PRTG Core server:
   • Windows: C:\\Program Files (x86)\\PRTG Network Monitor\\snmpmibs\\
   • Linux probe: /usr/local/prtg/snmpmibs/
2. Open the PRTG web interface: Log in as administrator.
3. Upload the MIB file (from PRTG 22.x): Navigation: Setup → System Administration → SNMP MIBs → Upload MIB file. Button “Upload MIB File" → select .mib file → confirm.
4. Restart PRTG services: Setup → System Administration → Restart Core Server so that the MIB is loaded.
5. Verify MIB import: When creating an “SNMP Custom Table" sensor, check whether the Didactum OIDs are displayed with readable names.

3.3 MIB configuration reference (main OID ranges)

-- DIDACTUM-RACKMONI2-MIB configuration reference
-- OID root: 1.3.6.1.4.1.3854 (Didactum enterprise OID)
 
-- System information:
   sysDescr          1.3.6.1.2.1.1.1.0        -- Device description
   sysName           1.3.6.1.2.1.1.5.0        -- Device name
   sysUpTime         1.3.6.1.2.1.1.3.0        -- Uptime (hundredths of seconds)
 
-- Temperature sensors (sensor 1–8, {n} = sensor index):
   tempValue         1.3.6.1.4.1.3854.1.2.2.1.16.1.3.{n}  -- Value × 10
   tempStatus        1.3.6.1.4.1.3854.1.2.2.1.16.1.4.{n}  -- 0=OK, 1=Warn, 2=Alarm
   tempHighAlarm     1.3.6.1.4.1.3854.1.2.2.1.16.1.7.{n}  -- Upper threshold
   tempLowAlarm      1.3.6.1.4.1.3854.1.2.2.1.16.1.8.{n}  -- Lower threshold
 
-- Leakage sensors:
   leakStatus        1.3.6.1.4.1.3854.1.2.2.1.18.1.4.{n}  -- 0=OK, 1=Leakage
   leakName          1.3.6.1.4.1.3854.1.2.2.1.18.1.2.{n}  -- Sensor name
 
-- Humidity sensors:
   humValue          1.3.6.1.4.1.3854.1.2.2.1.17.1.3.{n}  -- Value in % RH
   humStatus         1.3.6.1.4.1.3854.1.2.2.1.17.1.4.{n}  -- 0=OK, 1=Warn, 2=Alarm
 
-- Voltage sensors:
   voltValue         1.3.6.1.4.1.3854.1.2.2.1.15.1.3.{n}  -- Value in V × 10
   voltStatus        1.3.6.1.4.1.3854.1.2.2.1.15.1.4.{n}  -- 0=OK, 1=Warn, 2=Alarm

All OIDs listed below are based on the Didactum enterprise OID base 1.3.6.1.4.1.3854. The placeholder {n} represents the sensor index (1 = first sensor, 2 = second sensor, etc.).

Important: 

Didactum returns temperature values with a factor of 10 (e.g. 235 = 23.5°C). In PRTG, enter the value 0.1 under “Factor" in the channel configuration!

4.1 Temperature sensors

4.2 Leakage sensors

4.3 Humidity sensors

4.4 Additional sensor OIDs

4.5 Status code meaning (enum values)

5.1 Add Device in PRTG

1. In PRTG, navigate to the desired group under which the Didactum device should appear.
2. Click on Add Device. Enter hostname or IP address.
3. Settings: SNMP version v2c, community string, port 161.
4. Save the device. PRTG will now attempt to reach the device via SNMP.

5.2 SNMP Custom Value Sensor (single value)

A separate SNMP Custom Value sensor is created for each sensor value:

1. On the Didactum device in PRTG: + → Add Sensor → SNMP Custom Value.
2. Configuration:
   • Sensor name: e.g. Temperature Rack Front
   • OID: 1.3.6.1.4.1.3854.1.2.2.1.16.1.3.1
   • SNMP Data Type: Integer
3. Channel settings (important for temperature sensors!):
   • Unit: Custom → Unit: °C
   • Factor: 0.1 (value ÷ 10, since Didactum outputs × 10)
   • Decimal Places: 1
4. Limits:
   • Warning limit (upper): 35 °C
   • Error limit (upper): 40 °C
   • Warning limit (lower): 5 °C
5. Save the sensor. PRTG will begin data acquisition according to the configured scan interval.

5.3 SNMP Custom Table Sensor (all sensors at once)

With the SNMP Custom Table Sensor, all channels can be queried using a single table OID – particularly efficient for devices with many sensors.

1. On the device: + → Add Sensor → SNMP Custom Table.
2. Enter table OID:
   • Temperatures: 1.3.6.1.4.1.3854.1.2.2.1.16.1
   • Leakage: 1.3.6.1.4.1.3854.1.2.2.1.18.1
3. Configure columns:
   • Column .2 → Sensor name
   • Column .3 → Measured value (Integer, factor 0.1)
   • Column .4 → Status code (0/1/2)
4. Automatically adopt sensor channel names from MIB column .2.
5. Configure limits and notifications, then save the sensor.

Hint: The SNMP Custom Table Sensor significantly reduces the number of required sensors and puts less load on the device.

SNMP traps allow the Didactum device to immediately send a notification to PRTG in the event of alarms – without PRTG having to actively poll. Ideal for time-critical events such as leakage alarms.

6.1 Enable SNMP Trap Receiver in PRTG

1. In PRTG: Setup → System Administration → Core & Probes → Probe Settings.
2. Enable option SNMP Trap Receiver. UDP port 162 must be opened in the firewall.
3. Create sensor: + → Add Sensor → SNMP Trap Receiver.
4. Trap filter: OID 1.3.6.1.4.1.3854 (all Didactum traps), source IP: IP of the Didactum device.
5. On the Didactum device: enter SNMP Trap Receiver = IP of the PRTG server, port 162.

6.2 Important Didactum Trap OIDs

1. PRTG: Setup → Notifications → Create new notification.
2. Trigger: Sensor in Down or Error state → Immediately (0 minutes delay).
3. Method: Email to administrator distribution list AND SMS to on-call number.
4. Subject template: [ALARM] Leakage detected: %sensorname on %device (%datetime)
5. Sensor filter: Only notify sensors with tag leakage or didactum-leak.
6. Assign notification to the leakage sensor: Sensor → Settings → Notifications.

7.2 Recommended thresholds for rack monitoring

Diagnostic commands

# SNMP Walk – list all available OIDs of the Didactum device:


snmpwalk -v2c -c public 192.168.1.100 1.3.6.1.4.1.3854
 
# Query single OID (sensor 1 temperature):


snmpget -v2c -c public 192.168.1.100 1.3.6.1.4.1.3854.1.2.2.1.16.1.3.1
 
# SNMP v3 query:


snmpget -v3 -l authPriv -u snmpuser -a SHA -A passwort123 \\ 
        -x AES -X encryptpw 192.168.1.100 1.3.6.1.4.1.3854.1.2.2.1.16.1.3.1

Appendix: OID quick reference