An essential element of the infrastructure for every logistics operator is a fleet of barcode scanners (or RFID readers), due to the necessity of managing warehouses, preparing orders, tracking shipment routes, etc. The operator’s employees are generally equipped with portable terminals running on the Windows CE or, in the case of newer devices, Windows Mobile operating systems. Typical representatives of this group are products from companies such as Psion Teklogix (Workabout Pro, 7535), Intermec (CK30), and Symbol (MC9090).
In most applications, these devices perform well as barcode scanners and data collectors, which then connect to a central terminal via a WiFi network or via a wired connection using a docking station. Information transfer can occur periodically (“batch” mode, where read data is stored on the terminal until synchronization with the central terminal) or in real-time (“real time” mode). However, there are operations, such as order picking, cross-docking, or parcel management, where the dimensions and weight of the scanner can be a significant factor that prevents optimal efficiency. The purpose of this article is to present an alternative that improves work efficiency without the need to replace the existing infrastructure used by the logistics operator.
Terminals used in logistics that have the Windows CE or Windows Mobile (Win-CE/WM) operating system are usually equipped with WiFi and Bluetooth wireless network interfaces. Due to transfer speed, the WiFi network is used for data exchange and synchronization with the central terminal. A disadvantage of this technology is the relatively high power consumption, which entails the need for frequent charging of the terminal’s batteries. From the perspective of this article, the Bluetooth network is much more interesting.
The Bluetooth network standard allows for the communication of a wide range of devices, both for general use (mobile phones, printers, wireless headphones) and professional use (including barcode and RFID scanners). The Bluetooth specification distinguishes three classes of products (based on emission power and, consequently, range):
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Class 1 with 100 mW emission power and a range of up to 100 m
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Class 2 with 2.5 mW emission power and a range of up to 10 m
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Class 3 with 1 mW emission power and a range of up to 1 m (rarely encountered and practically unused in professional solutions).
The basic unit is the so-called piconet, which consists of a master node and a maximum of 7 slave nodes. Slave nodes are subordinate to the managing node (master) and can only communicate with it. This means that up to 7 other devices (operating in slave mode) can be connected to a Windows CE/Windows Mobile terminal equipped with a Bluetooth interface. The low power consumption of Bluetooth devices and the growing popularity of this type of network have led to the emergence of barcode and RFID scanners based on this technology. They implement the Bluetooth SPP (“Serial Port Profile”), which is supported by virtually every WinCE and Windows Mobile platform.
The article comes from the magazine “Logistyka” 3/2009.