Electronic Shelf Label is a fast emerging and popular technology that touts to eliminate the paper labels that are often changed weekly in grocery stores- freeing up labor and reducing paper waste. ESL would also eliminate discrepancies between shelf and cash register prices and allow the flexibility to make immediate price changes.
The system essentially consists of wireless dialogue between the Access Point unit, the Display Label, interfaced with the Central Host/POS System at one or more sales points.
The customer may use his own proprietary RF protocol or use the versatile TI proprietary SimpliciTI protocol stack.
Key Design care abouts include range of coverage, size, ease of use, battery life of the display label module, reliable and secure wireless transmission.
Each Label has a LCD/E-Ink Display that shows the price and UPC of the product, an RF Transceiver block and a microprocessor. The node can be implemented either using a TI standalone RF SOC-CC2510 that contains a built-in processor or it can be implemented using the TI RF CC2500 transceiver in conjunction with the MSP430 microprocessor. These ultra low power RF ICs provide high performance wireless communication at 2.4GHz.Use of the RF transceiver implements 2 way communication, expanding the scope of the system to include features such as maintaining inventory with the use of RF ID tags on the products. The node is powered by battery and thus the low power ,high performance features of both the CC2500 /CC2510 and the MSP430 lend themselves really well to maintain longer battery life.
The Access Point unit is a RF transceiver along with a simple microprocessor that can implement the required RF protocol. TI’s solution for the AP includes the CC2500 RF transceiver, CC2590/2591 RF front end and the processing power provided by the MSP430.The AP unit needs to be able to communicate with each and every node in its segment. In order to improve the propagation characteristics at 2.4GHz, CC2590/CC2591 is used to improve range of coverage in the AP-multiple label communication network. CC2590/CC2591 increases the link budget by providing a power amplifier for improved output power and an LNA with low noise figure for improved receiver sensitivity.
The AP can hook up to the Central Host/POS via one of the 3 interface options namely: RS-232, WLAN or POE-Power over Ethernet.
This entire system may also be implemented in the sub GHz operation range using the CC1101+MSP430 combination or the CC430 solution. The sub-1GHz can help achieve more range and avoid possible interference that are frequent in the 2.4GHz band. However the product will be geographically limited.
Thus price on the labels can be updated; stock inventory can be checked etc all from just one push at the Central Host/POS system.