Multi-channel Infrared Temperature Monitoring System, RS485 Modbus

Sensor Features

  • Miniature non-contact temperature sensor
  • RS485 Modbus interface
  • Measures temperatures from -20°C to 1000°C
  • Withstands ambient temperatures of 120°C without cooling

PM180 Touch Screen Interface Features

  • 6-channel temperature display with configuration, alarms and data logging
  • Analogue and alarm relay outputs via optional modules

System Features

  • Low-cost standalone 6-channel temperature monitoring system
  • Build larger systems using the PM180’s separate Modbus Master and Slave interfaces

General Specifications

Temperature Range
-20°C to 1000°C
RS485 Modbus RTU
±1% of reading or ±1ºC whichever is greater
± 0.5% of reading or ± 0.5°C whichever is greater
0.2 to 1.0
Response Time, t90
125 ms (90% response)
Spectral Range
8 to 14 μm
Supply Voltage
6 to 28 V DC
Supply Current
50 mA max.
Baud Rate
9600 baud (other configurations available upon request)
Modbus Data Format
8 data bits, no parity, 1 stop bit (other configurations available upon request)


Configuration Method
Via PM180 touch screen, or directly via RS485 Modbus
Configurable Parameters
Emissivity Setting, Averaging, Peak/Valley Hold Processing, Reflected Energy Compensation

Field of View Diagrams

Please note: The given measured spot size contains 90% of the energy detected by the sensor. We normally recommend the target is at least twice as large as the given measured spot for maximum accuracy. Sensors may be used at longer distances than the above diagrams show. There is no maximum measurement distance in clean air; this is because the PyroMiniBus detects only the wavelengths of infrared radiation that are not absorbed by the atmosphere.

Mechanical Specifications

Stainless Steel
18 mm diameter x 45 mm long (excluding cable gland)
Thread Mounting
M16 x 1 mm pitch
Cable Length
1m (longer lengths available to order)
Weight with Cable
85 g

Environmental Specifications

Environmental Rating
Ambient Temperature Range
PyroMiniBus sensor: 0°C to 120°C including cable
PMBHUB junction box: 0°C to 80°C
Relative Humidity
95% max. non-condensing

Electromagnetic Compatibility Standards

EN61326-1, EN61326-2-3 (Electrical Equipment for Measurement, Control and Laboratory Use – EMC Requirements – Industrial)

The PyroMiniBus may be installed as a new temperature monitoring system, or integrated into an existing Modbus network.

With two Modbus interfaces, the PM180 makes an ideal local display for a group of sensors as part of a larger system.

The PMBHUB junction box makes it easy to connect the system together.

Never miss a critical temperature event. In condition monitoring applications, the PyroMiniBus system is an always-on solution that can replace manual checks with a handheld thermometer or expensive thermal imager.

For example, some typical uses include:

Typical Applications

Curing ovens
Fibreglass impregnated with epoxy is cured in an oven to increase strength. PyroMiniBus sensors are placed inside the oven at up to 120°C, to build up a temperature profile at many points on the entire surface of the workpiece, and to communicate the measured temperature to the heating system that controls the hot air blowers in the oven. Industries include boatbuilding and aerospace as well as many others.
Industrial bakery
Check the temperature profile of bakery products at multiple points along a conveyor oven.
Corrugated board manufacturing
Monitor the web temperature along an entire corrugator, with local displays for each section of the production line, and centralised monitoring in the control room. Sensors withstand 120°C, and can be used in high-temperature areas such as single facers without cooling.
Power distribution
Monitor the temperature of busbar joints in switchgear cabinets. Hundreds or even thousands of points can be monitored on the same network using the PyroMiniBus system.
A large system of PyroMiniBus sensors can monitor the paint curing process at several points.
Monitor temperatures around the entire vehicle in environmental test chambers.
Condition monitoring
A network of PyroMiniBus sensors can monitor all the bearing temperatures on a machine, a runout table, or the whole factory. The PyroMiniBus is ideal for measuring the temperature of all painted metal surfaces.
Infrared curing
Arrays of sensors fitted on a rig of infrared curing lamps ensure an even temperature profile along the part being cured. Surface coatings, paint and epoxy are ideal target materials, among many others.
Gas cylinder filling
Monitor temperatures to improve repeatability in the filled volume and improve filling efficiency. The temperature of every cylinder on a filling rig is easily monitored with no need to manually move contact probes.

Connect up to 6 PyroMiniBus sensors to each PM180.

Connect up to 247 PM180 sub-networks or individual PyroMiniBus sensors directly to another Modbus network via the PM180’s Modbus slave interface.

The PM180 is also compatible with PyroBus, PyroMini and FibreMini sensors.

The PMBHUB junction box is designed for use with PyroMiniBus sensors. It is also compatible with PyroMini and FibreMini sensors via a suitable cable.

Please note: The cable diameter on PyroBus sensors does not fit the PMBHUB cable glands, so PyroBus sensors should be connected to the PM180 by other means.


Electrical Installation

Wire colour codes for PyroMiniBus sensors

Dimensions (mm)

PM180 6-Channel Hub

6-channel touch screen hub for temperature display, alarms, configuration and data logging. Isolated RS485 Modbus master and slave interfaces allow multiple hubs to be connected to a larger network. Optional modules provide analogue and relay outputs. Surface mounting.

Panel Mounting Kit

Allows the PM180 to be fixed behind a panel.

Air Purge Collar

The air purge collar is used to keep dust, fumes, moisture and other contaminants away from the lens. Air flows into the fitting on the side and out of the aperture at the front.

Fixed Mounting Bracket

The L-shaped fixed mounting bracket offers a rigid support for the sensor and allows fine rotational adjustment about one axis.

Adjustable Mounting Bracket

The adjustable mounting bracket consists of a fixed mounting bracket plus another L-shaped bracket. When assembled as shown, the adjustable mounting bracket offers a rigid support for the sensor and allows fine two-axis adjustment.

Laser Sighting Tool

The Laser Sighting Tool screws onto the front of the sensor during installation and shows precisely where the sensor is aiming. Once the sensor has been aimed at the centre of the target and locked in position, the Laser Sighting Tool can be removed. The laser is operated via a latching push button on the front of the tool.

Dual Laser Sighting Bracket

The Dual Laser Sighting Bracket is a sturdy mount for the sensor and provides continuous target sighting while measurements are being taken. Two parallel lasers indicate the centre of the measured spot and are controlled by a remote switch on the electronics module.

Protective Plastic Window

When fitted over the lens of the sensor, the protective plastic window in stainless steel holder provides mechanical protection and helps retain fragments of lens in case of damage. Adjust the sensor’s emissivity setting to compensate for the presence of the window for maximum accuracy. This accessory is ideal for the food and pharmaceutical industries.

PyroMiniBus Infrared Temperature Sensors

Model Description
PMB21 2:1 (wide-angle) divergent optics
PMB201 20:1 (general-purpose) divergent optics
PMBXCF Close-focus optics (3.5 mm spot diameter at 50 mm distance)

Touch Screen Interface Module (optional)

Model Description
PM180 6-channel touch screen terminal with temperature display, alarms, sensor configuration and data logging for up to 6 PyroMiniBus, PyroMini, PyroBus or FibreMini sensors. Separate RS485 Modbus Master and Slave interfaces.

Junction Box (optional)

Model Description
PMBHUB Wall-mounted IP65 junction box for PyroMiniBus. Allows up to 6 sensors to be easily connected to a PM180 via the included 8 cable glands and removable screw terminals.

Output Modules (optional)

Model Description
M-7061-D-G-CR Relay output module for PM180 touch screen terminal, 12 channel, DIN rail mounted. Each relay can be assigned to any alarm via the PM180 interface.
M-7024-G-CR Analogue output module for PM180 touch screen terminal, 4 channel, DIN rail mounted. Each output can be assigned to any measured temperature.