Thursday, October 27, 2016

IOT : RFID - Radio Frequency Identification

RFID is next line of Identification technique to that of existing serial numbers and Barcodes. RFID means Radio Frequency Identification, which suggests that it uses Radio Frequencies. This is one of the most important technology in the Internet of Things, as scanning an object/Item using barcode is not an effective way to manage the IOT Applications.

Why RFID and Why Not Barcodes?

The Existing Barcode system will only help identifying an object or something else when the barcode is scanned or at least in line of sight, which holds good for most of the cases today. In a fast paced world we are still waiting in lines for billing your Shopping Cart. This consumes lot of time especially during weekends where the crowd is more.

RFID will enable us to identify the objects without actually scanning and there is no need to be in line of sight at all. A simple scan will enable the reader to identify the items with in a refined search area.

Example: - Finding a specific Item in a group of similar Items is hell of a job when you have to scan all the objects using Barcodes, whereas using RFID you will just scan the stack and BINGO you will be able to differentiate.

How exactly will RFID work?

Similar to Barcodes , RFID will also have serial code for each item but the way its reads is different. An RFID system consists of three components an antenna and transceiver (generally combined into one reader) and a transponder (the tag). The antenna uses radio frequency waves to transmit a signal that activates the transponder. When activated, the tag transmits data back to the antenna.

This data is generally used to notify a programmable logic of something like getting details of the Item, Opening access Gate or for a transaction at a Toll Gate etc.


More Info on RFID

Since we are talking about radio frequency we will also have to talk about range of this frequency and Power used for transmitting the frequency

Range of Frequencies : There are two types Low-frequency RFID systems (30 KHz to 500 KHz) which have small transmission ranges (generally less than six feet) and High-frequency RFID systems (850 MHz to 950 MHz and 2.4 GHz to 2.5 GHz) offer longer transmission ranges (more than 90 feet). It’s easy for us to guess that, the higher the frequency, the more expensive the system.


Power/Energy: we have two types of RFID tags, Passive and Battery powered. Passive RFID tag uses the radio energy from the Reader/Interrogator or the device which is requesting information to relay back the details. The Battery powered RFID tag use the energy from a small embedded battery to relay the information.


Thursday, October 13, 2016

OracleApps Table Naming Conventions for _B, _TL and _VL

The most seen format of tables in Oracle are the general tables, views, synonyms etc . But we alos have others like _B,__TL and _VL which have their own specific operation and usage. Let’s see what they actually define within them and how they are different from general tables,views etc.


_B these are the BASE tables.
  • They are very important and the data is stored in the table with all validations.
  • It is supposed that these tables will always contain the perfect format data.
  • If anything happens to the BASE table data, then it is a data corruption issue.

_TL are tables corresponding to another table with the same name minus the _TL. These tables provide multiple language support. For each item in the table without _TL there can be many rows in the _TL table, but all with different values in the LANGUAGE column.

_VL are views for multi language tables which combines the row of the base table with the corresponding row of the _TL table where the LANGUAGE = USERENV('LANG').


What does this mean, let get into details with an example.

Let’s say we have a record in BASE table with some name as TABLENAME_B. This can have multiple records in TABLENAME_TL table with LANGUAGE column different for each record.


Now how does TABLENAME_VL come into usage is when a user runs a select on this table only one record is displayed based on his language setting if at all that language exists in the TABLENAME_TL table.

If you want to see the records, you have to change the NLS_LANGUAGE parameter as per the language availability in _TL tables.