I/O Database

What is an I/O Database?

In the field of instrumentation, an I/O database (Input/Output database) refers to a structured collection of information that defines the input and output points of an instrumentation system. It is commonly used in industrial control and monitoring applications.

An I/O database serves as a configuration tool for mapping physical signals from sensors, actuators, and other devices to the input and output channels of a control system. It provides a way to define and organize the various inputs and outputs that the system will interact with.

What is included in an I/O  database?

The I/O database typically contains information such as:

1. Tag or point name: A unique identifier assigned to each input or output point.
2. Service Description: A short description about the type of service in process to identify the function of a specific device or machine.
3. Signal type: It indicates the type of signal being measured or controlled. In this case, we have Analog Input, Digital Input, Analog Output and Digital Output.
   1. Analog inputs typically measure continuous physical quantities like Pressure, Level, Flow, Temperature, voltage and current. 
   2. Digital inputs represent discrete on/off states
   3. Analog outputs control continuous variables like motor speed or valve position etc.,.
   4. Digital output provides discrete on/off and open/close signals to drives and valves.
4. Instrument Type: This filed indicates the type of device or instrument like Limit switch, Pressure Transmitter, Control Valve etc.,
5. P&ID Number: This filed will show the corresponding P&ID No. in which the instrument is covered. This data is important to trace the instrument as per P&ID.
6. Instrument Location: This shows where the instrument is located either in Field or any specific location like CCR, Compressor Room etc.,
7. Measurement Range: This filed shows the process parameters High and Low range value 
8. Engineering unit: This field indicates the Engineering unit of the process value being measured or controlled.
9. Alarm and status information: Any predefined alarm conditions or status flags associated with the point.
10. PV Format: This field indicates the number of decimal points which needs to be shown on display.
11. Control System type: From this field we can identify which type of Control system the instrument is connected to DCS/IPS/FGS.
12. Control System Detail: This filed will show the specific detail of the Control system in a plant like DCS-002, IPS-042 etc.,
13. Marshalling Panel Detail: This field contains the detail of Marshalling panel number to which the instrument is terminated. Ex: 44-MC-401
14. Marshalling Panel TB Detail: This will show the Terminal block detail where the instrument is connected to inside the Marshalling panel.
15. Signal Interconnection Cable (SIC) Detail: This will show the Interconnection cable detail between Marshalling panel and System Cabinet Panel
16. System Cabinet Detail: This field contains the detail of System cabinet panel number to which the instrument is terminated. Ex: 44-SC-401
17. Rack Detail: This field shows the detail of Rack number to which the signal is connected.
18. Module Detail: This field shows the module detail inside system cabinet to which the signal is connected.
19. Address or channel number: The field contains the specific location or channel number where the input or output is connected in the control system.
20. Field Cable tag no.: This field gives the detail about the field cable which is connected to the instrument.
21. Field Cable Size: This indicates the cable size detail. Ex: 2Cx2.5 mm².
22. Junction Box (JB) No.: This field contains the detail of junction box to which the instrument is terminated. Ex: 44-JB-19005
23. Junction Box TB No.: This will show the Terminal block detail where the instrument is connected to inside the JB.
24. Loop Powered: This field indicates whether the device is loop powered.
25. Line Monitored: We can identify whether the loop is line monitored or not through this data.
26. Intrinsic/Non-Intrinsic: Whether the loop is Intrinsic safe or Non- Intrinsic signal can be identified from this field.
27. Communication protocols: The communication protocols and parameters used to interface with the devices.

What is the purpose of an I/O Database?

The I/O database is typically created and managed using dedicated software tools provided by the control system manufacturer. It allows engineers and technicians to configure the system, assign appropriate tags, define scaling parameters, set alarms, and establish communication settings.

By maintaining an organized and structured I/O database, it becomes easier to configure, troubleshoot, and maintain the instrumentation system. It provides a central reference for understanding how signals are mapped within the system and facilitates efficient operation and maintenance of the control system.

Sample I/O database

Let’s take a look at a sample I/O database format to understand it in more detaiLs and also u can able to download the template for preparing the I/O data base.