Mar 6, 2018

Convert Your USB Port in to Many Serial Ports

Nowadays almost all the laptops are not having any serial ports on them. This, in fact, creates a lot of problems for all Automation and electronics engineers as daily we guys have to communicate with external devices over serial communication. Many options are available in the market through which we can convert USB Port on our PC/Laptop to Serial/RS485 port. But we should take utmost care while buying as these converters are not so reliable and can let failure at the site.

Convert Your USB Port in to Many Serial Ports

Convert Your USB Port in to Many Serial RS232/RS422/RS485 Ports

Today in this post we will discuss about the different type of options available to convert existing USB port in to Serial / RS485 port. Many companies have started manufacturing these converters as these are easy to made and are in much demand due to lack of serial port on new laptops. There are devices available in the market for RS232 to RS485 converter. In fact in this world driven by electronic and automation technologies, we can find out everything to convert the signal and protocol format as per our application demand.

One USb, get up to 16 Serial Ports:-

There is one company "ByteRunner" whose USB to RS485 converters are very popular in the market. The company claims to have even 16 serial ports converter. Yes, that is you can have 16 different comms on your laptop just with their device. All the 16 different comms are individually configurable and separate/different settings can be assigned to them.This USB to Serial Adapter is suitable for remote access, retail and industrial applications, data collection and other applications requiring high-speed RS-232 communication ports.

Small USB 16 port Device

Moreover, these devices are capable of Speed of Serial port speed up to 230,400 bps or 921,600 bps depending on the model and provide you with features like Full modem control signals & data signals support. So these devices prove to be boon for every automation engineer where we have to daily deal with serial commiunication devices.

One more company named "Logica" also manufactures USB to RS422/Rs485 converter and it allows to convert an output signal RS232 from a PC or another device into an RS485 or RS422 electrical standard. These devices also have the feature of Automation Transmission and Hardware Transmission which makes these devices a versatile equipment for all your communication needs.

Logica USB to RS422 Converter

Later in coming articles, we will also discuss about the circuit of this Converter and procedure to make it at home. Till then you can subscribe to Automation-Talk by Email to get all latest updates.

Mar 4, 2018

Conzerv Energy Meter EM6436 Modbus Communication and Connection Diagram

Conzerv has a range of EM series Energy meter and there are various different models available for your different need and according to the application. Conzerv Energy meter comes with and without Modbus communication feature, so be sure when selecting Energy Meter according to the application. If you want to communicate it with PLC then make sure that it is MODBUS Enabled.

The EM series Power meters offer complete load management facilities in a compact package. If you like to see more such posts, please subscribe to Automation-Talk by Email.

How to check whether Conzerv Energy meter is MODBUS enabled?

1) First of all, check that terminals 7 and 14 of meter does not have black dot mark, if there is a black dot market on it then it is not MODBUS enabled.

2) Secondly, check that on the front left bottom side RS485 is written and the color of the dot before this, if the color of the dot is white then it is MODBUS enabled and if it is black then it is not MODBUS enabled.

All Conzerv Energy and power meter come with different function keys in the front side for easy set up of the parameters and also some models have TURBO key through which you can directly go to set up mode.

Connection Diagram of Conzerv EM series Energy Meter

NOTE:- Click on the picture for a clear view.

In the above picture, you can see the connection of energy meter. Connect your meter accordingly. The meter has 3 line display and display the parameters sequentially one by one i.e their name and value one by one.

Now the main question is how to communicate Conzerv Energy Meter in MODBUS?

So here is the answer, first of all, make proper hardware connection of MODBUS accordingly that is connect positive of PLC RS485 port with terminal 7 and negative of PLC RS485 port with terminal 14 of Conzerv Energy meter.

Now you have to make PLC program accordingly, generally, in MODBUS we read the parameters like a line to line voltage, frequency, current, power factor etc. Each parameter has its unique address in the energy meter and it has to be read through the query in MODBUS.

Make sure to set the node id, baud rate, parity in yours Conzerv energy meter properly using the setup mode.
You can download the address map of Conzerv Energy meter EM series from here .

Click here to download.

Now the question is How to read data from Conzerv Energy meter in MODBUS using OMRON PLC.

You can review the Omron PLC MODBUS communication from here.

So here is the Data format to read:- 01 03 04 (address - 1) 02

Make sure to subtract 40001 from the address.

Response from energy meter:- 01 03 00 05 0486 9042 4800

Here the value of the parameter in response is 4248, remember that the response of Conzerv Energy meter is always in float, so make sure to convert it accordingly. For example in the above response, the value returned by EM is 4248 in float which is equal to 49.98 in decimal and it is the value of frequency.

So accordingly you can read others parameter too by using the above query format. Hope you like this article and if you do, do not forget to subscribe to Automation-Talk by Email.

Feb 19, 2018

Auto Mains Failure PLC Program using Omron PLC

"Auto Mains Failure System" is Employed for Auto startup of the DG when the mains supply fails. This is a very common system and is the first step in DG synchronization. Here we will see that what is the basic concept in AMF? What hardware is required to set up AMF and how PLC Programming is done.

Auto Mains Failure PLC Program

First of all let us understand what is AMF?

Generally, all the major industries/companies/institution have the DG for power backup, but when main power is cut off, someone has to go to start the DG and this takes time and also a man has to be kept for this purpose. So to eliminate this process PLC panel is installed to Auto start the DG when main power fails. Subscribe to Automation-Talk by Email for more such tutorial.

Working of Auto Mains Failure

When the main power goes, a signal is received to PLC and after 2 minutes DG starts. When the main supply fails signal is received by PLC then after a delay time (can be from 1 to 2 minute), the output for ACB/Contactor of DG is ON and DG starts automatically. Also, the ACB/Contractor of the main transformer if sent OFF command.

When main power comes then the signal is again sent to PLC and PLC off the ACB/Contactor of DG and after 2 seconds it on the ACB/Contactor of the main transformer and after 30 seconds it off the DG. DG is sent OFF command a little late so that the load born by DG for a long time can be compensated by running at no load for some time.

NOTE:- In 'No' condition, the ACB/Contactor of both DG and Main transformer should be ON.

So this is the main concept in DG AMF system.

In a simple system, there are generally 4 inputs and 4 outputs.


1. DG ACB/Contactor close feedback.
2. Transformer ACB/Contactor close feedback.
3. Transformer Voltage Available.
4. DG Voltage Available.


1. DG start.
2. DG Stop
3. DG ACB/Contactor close.
4. Transformer ACB/Contactor close.

For your better understanding below is the sample program. If you have any doubts then just write in comments and we will get back to you. Download the PLC Program for AMF:- Click here to Download.

Hope you like this article, if you do comment below and share it on social media. Hope to see you on next article.

Jan 21, 2018

Mnemonic Names of Commonly used Instructions in PLC

Mnemonic Names of Commonly used Instructions in PLC

In our daily programming of PLC like ABB, Allen Bradley, Omron, etc. we use Mnemonic and some of the very commonly used instructions in PLC are as follows. We know we have missed many of them, so please help us to complete the list by commenting the other mnemonic in the comment section.

Mnemonic Names of Commonly used Instructions in PLC

INSTRUCTION -------------------------------- MNEMONIC NAME

1. Examine if closed --> XIC --| |--

2. Examine If Open --> XIO --|\|--

3. Output Energized --> OTE --(OTE)- -

4. Branch Start --> BST

5. Next Branch --> NXB

6. Output Latch --> OTL --(L)--

7. Output Unlatch --> OUT --(U)--

8. One shot Rising --> OSR

9. Timer On-Delay --> Ton

10. Timer off-Delay --> Toff

11. Retentive Timer --> RTO

12. Count Up --> CTU

13. Count Down --> CTD

14. Reset --> RST --(RST)--

Hope you liked this simple tutorial on "Mnemonic Names". If you do, please show your love by sharing it with other and subscribing to our website.

Dec 27, 2017

Importance of Emergency Button in Control Panel

Designing any electrical machine or its control panel involves proper planning, designing and commissioning. All these steps are very important for effective working of the machine and operation through it. Machine Planning is very important in the designing of the machine as it decides the future of production through it. In the planning process of Electrical machine control panel, it involves many important aspects to be followed. Subscribe to Automation-Talk by Email.

Emergency in PLC programming

Emergency or Stop button plays a very important role in every control panel and every engineer should include Emergency button in there panel which should be in reach of the machine operator. While making a PLC program, emergency input should be used correctly so that it stops the whole machine at the time of need.

PLC Programming of Emergency Button

Programming an emergency button is very easy as you just need to add a normally closed contact in series with your PLC program. This you can do by adding the emergency contact on every rung of our ladder program at the start or can just actuate a memory bit with that and can use that memory bit everywhere you want to stop the program.

There is a big difference between emergency and a stop button though they look alike. So don’t do the mistake of not using an Emergency button in your panel.

Using Emergency button in Relay logic

If you are using only relay logic for your control panel, then also you can include an emergency button in the panel just add emergency button (NC contact) in series at the start of your electrical circuit.

Dec 17, 2017

Different Types of Motor Load Meaning

While selecting the AC motor for an application, we always first lookout that what type of load will be driven by AC Motor i.e. constant Torque load or variable torque load. Almost all of the automation and plc engineers must have seen all such type of loads. Also while selecting the VFD for an AC motor we have to select the VFD according to the Load type. But do we actually know what this load type means?

Well if not, then in this post we will try to understand the different types of load.

Different Types of Motor Load Meaning

What is Constant HorsePower Load?

The constant horsepower load is that type of load in which the torque requirement is more at low speed and as the speed increases the torque requirement decreases. This type of load examples can be found drill machines, lathe machines, and metal removing applications.

What is a Constant Load Torque?

In constant torque load, the torque requirement is always the same irrespective of the load speed. If we take the example of conveyor then the torque requirement of a conveyor is always same whether it is running at low speed or high speed.

What is Variable Type Load?

Variable torque load is a term which is used for loads that require low torque at low speeds and high torque at high speeds.

Examples of Variable type load are centrifugal pumps and fan. In the market, there are special VFD available for such type of applications that saves a lot of energy.

Hope that after reading this article, we now understood the different type of load meaning and next time we can easily identify the type of load that a motor is driving. Don't forget to subscribe to get all latest updates and also like our facebook page if you like Automation Talk.

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Nov 24, 2017

Difference Between Reflective, Retro Reflective & Through beam Optical Sensor

Sensors are the very important part of automation industry and are categorized into many types, like proximity sensor, level sensor, pressure sensor, photosensor or optical sensor etc. We widely used these sensor in our industry for object detection, fault detection etc. Sensor are those sensing device which senses and convert that to the electrical signal. In this tutorial we will learn what is the basic difference between a reflective or diffused photo sensor, retro reflective & through beam Optical or photo sensor. Subscribe to Automation-Talk by Email.

Difference Between Reflective, Retro Reflective & Through beam Optical Sensor
Image source:

On seeing the above picture, you must have got an idea that what is the difference between these 3 types of optical sensor.

Through beam optical sensor has transmitter and receiver as a separate device and work on the principle that whenever a object comes between transmitter and receiver a signal is sent. Used when sensing distance is large.

Retro reflective type of optical sensor has transmitter and receiver on same housing and they require a reflective surface called reflector for there working.

Reflective optical sensor are also called diffused photo sensor and has transmitter and receiver on same housing but they do not require any reflector for there working. Object to detected itself work as a reflector.

The main advantage of optical sensor's is that they do not do the difference between the object, unlike proximity sensor.

Nov 7, 2017

Motor Related Common Electrical Terms - Part 2

In the last section we studied about some of the frequently used motor electrical parameters in our day to day work. We have already understood about the different types of AMPS rating that a motor nameplate have, in this post we will try to understand about the design of motor that is what type of torque and speed curve motor have, we will also look in to efficiency, frame size, and frequency. Subscribe to Automation-Talk by Email.

Motor Related Common Electrical Terms

What Does Design of AC Motor Indicates

There are generally four types of design A B C D that an AC Motor can have. The design of AC Motor just indicates the type of speed v/s torque curve that the motor will have. The speed v/s torque curve for all the designs of the motor is below.

The standard industrial motor will mostly have the design B, it has reasonable starting torque with average speed and starting current with a good performance. In the above curve, we see that design C has the high starting torque so this type of motor is used where we have to start the high loads. Design D is the so-called high slip motor which tends to have very high starting torque but has high slip RPM at full load torque. Design D motors are generally suited for press and elevator applications. Design A motors are not particularly specified but are used where the high pull out torque is required.

What does efficiency of AC Motor Means?

Efficiency is indicated on the nameplate of the motor and in simple terms, it means that it is the amount of input energy that is converted into work. We should always select a motor that has high efficiency.

Meaning of Frame Size in AC Motor

As everything in this world has some size, same is the case with the motors. As the motor HP increases or RPM decreased the frame size of the motor increases. NEMA (National Electrical Manufacturers Association) has prescribed standard shaft diameter for the particular frame size so as to maintain a standard among all the motor manufacturers in the world.

What does Motor Frequency Indicates

Frequency on the motor nameplate means that for which input frequency motor is designed to operate. Most common motors have operating frequency of either 50 or 60 Hz.

We have understood some of the more common electrical terms in this post. We will also cover other commonly used electrical motor parameters in the upcoming post. If u have any doubts at any point please feel free to write in the comment section.

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