iRS-2R serial relay board from Iknowvations

Serial Port Data Acquisition

Serial Port Data Acquisition

Data Acquisition means to acquire required data in such a way that it can be easy to process it further. Data Acquisition System refers to a total system which will measure, analyze, store & display the information collected through various devices attached to it. These devices can be various sensors, switches or any other equipment that provides data in electrical form.

Sensors are basically devices that convert any physical quantity like Temperature, Pressure, light, Sound etc to an electrical signal. This electrical signal then can be measured electronically and processed as per our requirement.

The Data Acquisition systems are used where we want to keep an eye on some physical quantity or we want to take some action as per the data that we receive.

Let us take a very simple example. You have a fan at home. Now you want to make it automatic. That is it should be ON if temperature of your room is higher than say 25 degree Centigrade & be OFF as soon as the temperature is equal or below 20 degree Centigrade. This system can be called as Automatic Fan Controller.

Here to make your Fan ON or OFF, you have to first decide if the temperature of the room is Higher or lower than the prescribed limit. For this you have to first measure the temperature. To measure the temperature, you must have Temperature sensor. The temperature sensor will provide a voltage that is directly proportional to the temperature. So by measuring the voltage output of the temperature sensor, you come to know how much the temperature is. This is the Data – information that you are acquiring.

The voltage of the sensor is provided to a processor chip which is called ADC ( Analog-to-Digital Converter). This chip converts the analog voltage provided to it to digital data which can be easily understood by digital microcontroller IC. This is the processing part of the our automatic system.

Now that you have the Processed Data, you would like that data to be processed as you want to take a decision whether to make the fan ON or OFF. This the analysis part. Here you will take the appropriate decision based upon the analysis of your acquired & processed data. So after deciding if the temperature is above or below your limits, you will decide to turn the fan ON or OFF through electronic switch or relay which is attached to our automatic system.

Now that you know the concept of Data Acquisition system, let us see how we can do it practically. The term Serial port Data acquisition refers to a system wherein we require data through a card which is attached to serial or COM port of any PC or Laptop. The DAQ card or Board is attached with sensors. This board will acquire and process the data and present in readable form to PC through serial port. This data is then analyzed in PC and then again taken appropriate action through the card which is having relays as well.

iRSD-8R 8 channel Serial Relay & Daq Board

iRSD-8R 8 channel Serial Relay & Daq Board

iRS-8RD board from Iknowvations is such a card which is having 10 bit ADC on board as well as 8 Relays that can be used to control any electrical equipment. 10 bit ADC means that it can measure 1024th part of 5 V Dc input from the sensors attached to the input channels of the card. There are total 4 such analog channels out of 8 total available channels on this card. Other channels are digital channels that can be utilized to see if the input voltages are High ( digital 1) or Low ( digital 0). Using these digital channels you can come to know whether a button is pressed or not. This is also a kind of Data.

You can connect this card to your PC and with the help of predetermined commands ( the list of commands are provided in User Manual ), you can make yourself simple Automatic Fan Control system described above or can build much sophisticated system as you start gaining more knowledge & experience about Data Acquisition systems. To connect to the card you can use any serial communication program like Hyper Terminal or you can make your own using any higher level languages like Visual Basic, VC, VC++, C#, Delphi etc.

We have also other Serial port DAQ cards to suit your different requirements as shown below –

iRS-2R serial relay board from Iknowvations

iRS-2R Serial Relay & DAQ Board

4 channel RS232 relay board - iRS-4RD iknowvations

4 channel Serial Relay & Daq board.

Apart from this if you want higher resolution ( 12 bit) and USB based Data Acquisition then you can go for our U96 card.

U69 usb daq and relay card from

U96 – USB DAQ & Relay Card

For more technical information about all of the above Data Acquisition cards, please go through User Manuals of respected cards which can be downloaded from our download section at

If you want to buy theses boards, please proceed to our online Iknowvations Shopee where you will find all the details as well as prices & place the order.

If you want more information or help, do write to our support team at support(at) . They are ever ready to answer your any question.

Happy Data acquisitioning !


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