Tech Talk

Answer: The Soft Starter will slowly start the motor and run at full speed. The VFD can do the same thing however it will allow you to vary the speed of the motor. If the application requires motor speed to vary at any time then a VFD is the correct solution.

Answer: HART (Highway Addressable Remote Transducer) Protocol is the global standard for sending and receiving digital information across analog wires between smart devices and control or monitoring systems.

More specifically, HART is a bi-directional communication protocol that provides data access between intelligent field instruments and host systems. A host can be any software application from technician’s hand-held device or laptop to a plant’s process control, asset management, safety or other system using any control platform.

Answer: An unmanaged switch does not require any programming (plug and play) and has limited data management capabilities dependent on the manufacturer’s spec. A managed switch requires configuration and is generally used where redundant network communication is required. A managed switch allows the network to be optimized and gives users the ability to trouble shoot much more easily.

Answer: While both are detecting the presence or “proximity” of an object (is it there or not there) they use different technologies. A Photo sensor uses light while a Prox uses a magnetic field. There are two types of Proxies: inductive which only detects ferrous materials and capacitive which can detect any dense object. All Proxies are limited in their range of sensing which is typically less than 30mm. Some inductive units can provide an analog signal for distance detection. Photo sensors can see much further.

Answer: A two-wire transmitter has both power and communications on the same two wires. The power to run the transmitter comes from the device, which has its own supply of power.  Since the transmitter will increase the power consumption of the device to which it is connected we must ensure there will be enough voltage reaching the transmitter to allow the transmitter to operate. It is common to see a specification for the minimum voltage the transmitter needs. This is measured at the transmitter not the source.

A four-wire transmitter has four wires: two for the 4-20mA output and two for the power to supply the transmitter. This is usually an AC Voltage. In this case, the transmitter provides the power for the connected device it is connected.

Answer: If you are happy with PROFIBUS as a solution today then you can continue to use PROFIBUS. PROFIBUS will continue to be developed and supported for many years. If however you want to take advantage of the greater benefits of PROFINET (e.g. Wireless applications, high performance Motion Control, increased diagnostic particularly via the Web/email) then we suggest you look at PROFINET.

Answer: Yes and No. In the wireless world, line of sight is defined as the transmitter being able to ‘see’ the receiver.  A better way to think about this is that the transmitters have better vision than we do and the transmitters are able to ‘see’ through some objects.  There are many variables that will affect your wireless system such as operating frequency, operating power (watts), physical obstacles, environmental conditions, and more.  Therefore, ‘line of sight’ is just one of many important variables when you are designing your system.

Answer: This will depend on your operating frequency.  The ISM (frequencies reserved for Industrial, Scientific, and Medical applications) bands in North America operate in the 900 MHz, 2.4 GHz, and 5.8 GHz band widths and do not require a license to install and operate.  Technologies designed in these frequencies are able to handle interference, using such methods as Frequency Hopping Spread Spectrum (FHSS), and are not to exceed 1 watt of transmit power. 

Answer: Vision systems take sensing to a deeper level. Instead of just looking for the presence of an object we can now look at size, shape, colours, and alignment of an object. Other applications are barcode recognition and label identification. Perhaps you need to see the holes drilled into a multi-stepped block of aluminum for a robotic arm to tap for bolts. A camera can assist in this by identifying the block presence, rotation of the piece, location and size of the holes and relay that back to the servo system.