Monitoring system for equipment operating conditions

The basic element of the monitoring system is ST-50 the controller. It allows you to read measurements from the 1-Wire sensors (Dallas Semiconductor technology), and access them via Ethernet. It analyses entered alarm conditions and can react by turning digital binary outputs on and off, depending on the measurement threshold. It can also send e-mails.
It is able to independently connect to a data collection centre in order to report an emergency. The construction of this unit allows you to build autonomous monitoring systems, independently of the monitoring centre. It also allows for load reduction by reducing it to just “listening out” for alarms reported by the controller. The ST-50 controller works with the following measuring sensors: temperature T1, temperature and humidity THP110, with ILO880 input module and ILO004
output module.



  • Power supply: 12 V ~ 200 mA
  • Communication interfaces:
  • 1x Ethernet – RJ45 port with status indication (2x LED)
  • 2x 1-Wire – RJ45 port
  • 1x RS232 – 2×5 rack and panel connector
  • Memory settings: EEPROM non-volatile memory
  • Modular enclosure for DIN 35 mm strip


  • Allow for connecting up to 24 1-Wire devices.
  • 1-Wire type sensors (including humidity, temperature, digital binary input, voltage meters).
  • Continuous reading of measurements from connected sensors.
  • Length of the line including sensors: up to 100 m
  • 1-Wire lines use RJ-45 port, they provide power to devices (5V/1A).


  • with measurement devices on the 1-Wire line,
  • in Ethernet network (RJ45 output), with the master system using ModBus RTU protocol and UDP/IP protocol,
  • with GSM modem via RS232 port to send SMS messages.


  • You can set 24 independent alarms.
  • Responses to emergency situations:
  • – sending e-mails,
  • – possibility to change status of the 1-Wire switch (binary output),
  • – setting relay outputs in the ILO004 module.
  • Defining message content of user’s choice.


  • Range of measured temperatures: from -55 °C to 125 °C
  • Accuracy: 0,1 °C
  • Output: 1-Wire RJ 45
  • Dimensions: 42 x 58 x 26 mm


  • Range of measured temperatures: from -55°C to 125°C
  • Range of measured humidity: from 10% to 90%
  • Accuracy: 0.1°C, 1%
  • Output: 1-Wire RJ 45
  • Dimensions: 60 x 65 x 27 mm


  • 8 inputs in the form of low-voltage keys 0-10 mA
  • 16 memory pages, 256 bits each
  • 32-bit counters without overflow
  • 2 1-Wire RJ45 ports
  • Supply from the 1-Wire 5 V DC line
  • Dimensions: 58 x 88 x 17 mm


  • Number of relay outputs: 4
  • Type of relay outputs: NO/NC
  • Load capacity of relay contacts: 8 A / 250 V AC
  • Power supply: logic section from the 1-WIRE bus, 12 V DC / 13.2 V AC executive section from an external source
  • Relay status controlled by hardware
  • Relay status indication: LEDs on the enclosure, by system

We connect THP110 temperature and humidity sensor to ZPAS ST-50 controller. ILO004 output module was connected as the executive module. Planned logic provides for setting 4 alarms, two for switching outputs on, and the other two for switching outputs off. Fans and heaters with a capacity of not more than 2 kVA can be connected to outputs of the ILO004 module.

Monitoring software allows you to collect, process and visualize data collected by the hardware layer. The user receives a comprehensive monitoring system operated via web browser. The software also allows you to build any visualization and select just the measurements you need, both current as well as archived. This allows you to adjust the settings to suit individual needs of each client connecting remotely. It also has an extensive alarm handling mechanism. The mechanism for controlling access to data collected by the monitoring system distributes user rights both in terms of users’ roles in the system, as well as in terms of access to monitored facilities.
Archived data can be viewed using tables and charts. All system data can be printed. An additional advantage of the system is the fact that the number of system users is not licensed. Because of its use in monitoring systems, the system is based on two main communication protocols: SNMP (communication with power stations, network devices and UPS) and ModBus RTU (communication with energy meters, power parameters analysers, data hubs). However, with the ability to add drivers, it can work with any devices that use other communication protocols. The software works very well with data hubs which can provide communication buffer between other systems, such as fire protection, climatic conditions, access control or power supply parameters.