What does it do?
A Vutlan environmental monitoring system consists of a master monitoring unit (VT855G, VT825G or VT335G) and the sensors connected to it. The unit reads values such as temperature, humidity, voltage, water leakage, smoke and airflow; through dry contact inputs it monitors the status of equipment such as doors, UPS, generators and circuit breakers, and through relay outputs it drives fans, sirens or light alarms. No separate server or software is required: everything is configured in the unit's own web interface.
Analog sensors plug into the unit's RJ12 ports and are detected automatically. When ports run out, the CAN bus takes over: each VT408 extension unit adds 8 analog ports, and CAN sensors such as the VT490 are daisy-chained on the same line. A CAN line extends up to 225 m and up to 32 devices per line. Triggers, timers and logic schemes inside the unit react to events automatically; for example, when a temperature threshold is exceeded it starts a fan and switches the VT109 light tower to red.
Alarms are sent by e-mail, SMS (with the VT7670 4G modem), SNMP trap, Syslog and Telegram; SNMP v1/v2c/v3 and the MIB file allow connection to NMS software such as Zabbix. For remote outlet control inside the rack, the VT604G switched PDU uses the same interface. Where running cables is difficult, Vutlan also offers a LoRaWAN-based wireless sensor option; its suitability is assessed per project. The manufacturer, Vutlan s.r.o., is based in Bratislava (Slovakia).
Which scenarios does it fit?
The server and network room in a corporate building: VT335G or VT825G with temperature/humidity (VT490), door (VT530), smoke (VT560) and water leak detection around air conditioners (VT591 + WLC cable). When a threshold is exceeded, the on-call team is alerted by e-mail and SMS.
The compact VT335G for tight spaces: powered by 12V DC, with a VT335GDC version with 24–48V DC input for DC sites. The cabinet door, internal temperature and DC voltage (VT410) are monitored; where the site has no LAN, the VT7670 4G modem provides LTE access and SMS.
VT825G in the room housing the telephone system, UPS and rectifier: 16 dry contact inputs read the status of UPS, generator and circuit breakers, and the VT520 monitors mains voltage. Alarms are also forwarded to the existing monitoring system via SNMP trap.
VT855G: 2 CAN ports, 32 dry contact inputs, 8 isolated outputs and capacity for 150 physical sensors. VT490 sensors daisy-chained on rack fronts and backs, analog ports extended with VT408, and a VT604G switched PDU per rack.
Key features
- Sensor families: VT500 temperature, VT490 CAN temperature/humidity, VT520 AC voltage (0–246 V, 1% accuracy), VT591 water leak, VT560 smoke, VT530 door, VT580 dust
- Water leak: VT591 + WLC sensing cable; 3, 6, 10, 15, 25 and 50 m lengths can be joined, up to 100 m from the master unit, 15 s response time
- Daisy-chaining: up to 10 VT560 smoke or VT530 door sensors on one analog port; 32 devices on a CAN line (24 recommended), 225 m line length
- I/O control: 4 / 16 / 32 dry contact inputs, 2 × 240V 10A NC/NO/COM relays on VT825G and VT855G, 2 × 12V 0.25 A outputs on all units (VT109 light tower, siren, strobe)
- Notifications: e-mail (up to 20 recipients), SMS (with VT7670, up to 20 numbers), SNMP trap, Syslog, FTP log, Web-to-SMS, push and Telegram
- Integration: SNMP v1/v2c/v3 and downloadable MIB; reading data from external devices via SNMP GET; built-in Modbus TCP/IP, Modbus RTU with the VT485m extension (RS-485, 1000 m line); Zabbix template
- Automation and logging: up to 1000 elements (VT855G/VT825G) of triggers, timers and logic schemes; 1 s sampling, logs to microSD (SDXC up to 512 GB) and USB flash
- Power continuity: depending on order option, dual 230V AC, AC + 24–48V DC or dual DC inputs; 12V DC backup input; VT-ACCU rechargeable backup battery
- Network and access: Gigabit Ethernet, HTTPS/SSL, RADIUS, OpenVPN, three-level user access; failover to LTE with the VT7670 if the LAN goes down
Monitoring unit comparison
| VT855G | VT825G | VT335G | |
|---|---|---|---|
| Positioning | Corporate site, large data centre | Data centre, telecom facility, PBX room | Compact: cabinet, field cabinet, server room |
| Form and mounting | 19" 1U, sheet metal, 440 × 44 × 90 mm, 1.6 kg | 19" 1U, sheet metal, 440 × 44 × 90 mm, 1.5 kg | Desktop, sheet metal, 180 × 35 × 80 mm, 0.7 kg; 19" 1U, wall or DIN rail with accessories |
| CPU / RAM | 1 GHz, 2 cores / 128 MB | 720 MHz, 2 cores / 128 MB | 720 MHz, 2 cores / 128 MB |
| Ethernet | 10/100/1000 Mbit | 10/100/1000 Mbit | 10/100/1000 Mbit |
| Analog sensor ports | 8 (extendable with VT408) | 8 (extendable with VT408) | 4 (extendable with VT408) |
| CAN bus | 2 ports, 32 devices in total (24 recommended) | 1 port, 32 devices (24 recommended) | 1 port, 32 devices (24 recommended) |
| Dry contact inputs | 32 | 16 | 4 |
| Dry contact outputs | 8 isolated, 24V DC / 15 mA | — | — |
| Power relays (NC/NO/COM) | 2 × 240V 10A | 2 × 240V 10A | — |
| 12V outputs | 2 × 0.25 A | 2 × 0.25 A | 2 × 0.25 A |
| Max. physical sensors / elements | 150 / 1000 | 130 / 1000 | 100 / 700 ¹ |
| Power input | 100–240V AC; by option dual AC, AC + 24–48V DC or dual 24–48V DC; 12V DC backup | 100–240V AC; by option dual AC, AC + 24–48V DC or dual 24–48V DC; 12V DC backup | 12V DC main + 12V DC backup; VT335GDC for 24–48V DC |
| Backup battery slot | VT-ACCU or VT-BAT | VT-ACCU or VT-BAT | — |
| 4G modem / extension slot | VT7670 / VT485m or VT485r | VT7670 / VT485m or VT485r | VT7670 / VT485m or VT485r |
| Max. power consumption | 10 W | 10 W | 10 W |
Source: Vutlan Confluence DEN, "Comparison chart: Master modules" (last updated 15.06.2026) and the VT855G, VT825G (v5.0) and VT335G product pages. ¹ The VT335G product page states 1000 elements; the table uses the comparison chart value of 700. Modem, extension and battery modules are ordered separately; the exact configuration is settled in the BOM.
Scaling the system
When analog ports run out: VT408
The VT408 extension unit adds 8 analog ports over the CAN bus; connected sensors are detected automatically. If no other CAN devices are on the line, up to 24 VT408 units can be chained on one CAN line. Two VT408 units fit into a single 1U space with the VT125t bracket.
Long and busy CAN lines
A CAN line extends up to 225 m and carries 32 devices; Vutlan recommends 24. If the line will carry more than about 12 CAN devices, a CAN-12V-1A power module is added. The TR termination switch must be on at the last device of the line; the cable type (copper AWG24) is checked during the survey.
More dry contacts
If many alarm outputs such as UPS, generator or fire panel need to be read, a VT440 dry contacts unit is added to the CAN bus; each unit brings 32 or 64 contacts.
Modbus devices on site
Modbus TCP/IP is built into all units. For meters and devices speaking Modbus RTU over RS-485, a VT485m is fitted into the unit's extension slot; the RS-485 line extends up to 1000 m.
Vutlan environmental monitoring or NMS alarms?
- Measures the physical environment: temperature, humidity, water leaks, smoke, doors, mains voltage
- Connects on site to UPS, generators, fans and alarm devices through dry contacts and relays
- Reacts on site with its own logic schemes; can send SMS via the VT7670 even if the LAN is down
- Forwards readings to the NMS via SNMP and traps
- Monitors IT components such as servers, switches and virtual machines via agents or SNMP
- Provides central dashboards, maps, incident management and escalation
- Does not itself measure room temperature or water leaks; it needs a sensor source for that
- A ready-made SNMP template exists for Vutlan; the two systems work together
Promark's scope of services
- Survey: room/cabinet dimensions, risk points (air conditioning, pipes, doors), existing UPS and rectifier alarm outputs
- Datasheet-based design: unit selection, sensor placement, CAN line and WLC cable routing; BOM within 24–48 hours
- Installation: rack/wall mounting, sensor and dry contact cabling, VT604G PDU placement
- Commissioning: thresholds, logic schemes, e-mail/SMS recipients, SNMP and Zabbix integration
- Maintenance: firmware updates, sensor tests, configuration backup
- Field service across Türkiye and in Turkmenistan
Sectors
Related catalog products
Frequently asked questions
How do I choose between VT855G, VT825G and VT335G?
The VT335G is the compact unit: 4 analog ports, 4 dry contact inputs and 12V DC power, for cabinets and small server rooms. The VT825G is 19" 1U: it offers 8 analog ports, 16 dry contact inputs, 2 power relays and dual AC/DC power options. The VT855G, with a 1 GHz processor, 2 CAN ports, 32 dry contact inputs and 8 isolated outputs, is for large data centres and corporate sites.
How many sensors can be connected to one unit?
According to Vutlan's comparison chart, the total of physical sensors, dry contacts and relays is 150 on the VT855G, 130 on the VT825G and 100 on the VT335G. If the built-in analog ports are not enough, the VT408 adds 8 ports at a time and CAN sensors are chained on the line. Up to 10 smoke or door sensors can be chained on one analog port; the chain appears as a single element in the interface.
Does it integrate with SNMP and Zabbix?
Yes. The units support SNMP v1, v2c and v3; the MIB file is downloaded from the web interface and alarms are sent as SNMP traps. Vutlan's Zabbix template discovers sensors automatically over SNMP. The unit can also read data from other devices via SNMP GET.
Will I get an alarm during a power outage?
The VT520 measures mains voltage and detects the outage. The unit keeps running from the 12V DC backup input or the VT-ACCU rechargeable battery; Vutlan states that the battery lasts between 8 minutes and 8 hours depending on the connected load. Since the network switch will also lose power, SMS delivery via the VT7670 4G modem is recommended.
How does the water leak cable work and how long can it be?
The VT591 sensor detects the drop in resistance when water or another conductive liquid touches any point of the WLC sensing cable; response time is 15 s. WLC cable comes in 3, 6, 10, 15, 25 and 50 m lengths that can be joined, up to 100 m in total. It is laid as a perimeter under raised floors and around air conditioners and pipework.
Can I control outlets remotely with a PDU?
Yes. The VT604G provides 4 switched IEC C13 outlets in a 19" 1U chassis; each outlet can be switched on and off and the device rebooted from the web interface, via SNMP or via the API. It can also be triggered automatically by a logic scheme. The VT604G also works as a monitoring unit with 8 analog sensor ports and 2 CAN ports; it does not measure per-outlet current.
Just send us the number of rooms or cabinets to be monitored, approximate dimensions and the values you want to watch (temperature, water leaks, doors, UPS alarms, etc.) on WhatsApp. We return a BOM and quote within 24–48 hours. Across Türkiye and in Turkmenistan.