Handheld terminal

Definition Handheld terminal is has the following characteristics of portable data processing terminal. 1, with data storage and computing power 2, can be secondary development 3, with other data communication equipment 4, it was machine interface, specifically, have a display and input capabilities 5, battery-powered By the above definition, hand-held terminals are common PDA, cell phone, smart phone, bar code data collector, handheld data terminal IC card, hand-held fingerprint terminals, meter reading, and so on. Function In addition to basic functions handset also has some other features with the application and the system is closely related to, but also the selection of handheld devices need to be considered. 1, bar code scanner: There are two bar code scanning technology, laser and CCD, laser scanning can only be read one-dimensional bar code, CCD technology can identify the one-dimensional and two-dimensional bar code, the more popular view is one-dimensional bar code reading, laser scanning technology faster and more convenient than CCD technology. With bar code scanning hand-held terminal is often referred to as bar code data collector. 2, IC card reader: IC card reader features an integrated hand-held terminals are usually referred to as hand-held data terminal IC card, IC card is mainly used for card management 3, non-contact IC card reader: Integrated non-contact IC card reader enabled handsets are usually referred to as non-contact IC card handheld data terminals, mainly for non-contact IC card management. 4, built-in information button: the so-called information button is built-in non-contact IC card chip, mainly used for patrol. 5, fingerprint, matching: an integrated fingerprint module is mainly used for hand-held terminals, public security, social insurance, etc. 6, GPS: industrial applications primarily for security, but also a lot of lies in the civilian market, the drive to provide digital map and location-based services 7, GSM / GPRS / CDMA wireless data communications: The main function of wireless data communications by way of real-time data exchange with the database. In both cases, the main need to use this feature, one for data demanding real-time applications, the second is the application for various reasons, the required data can not be stored in the handset, it may be necessary data is too large, may be kept confidential, and so on. 8, GSM / GPRS / CDMA SMS Communication: Almost all wireless data communication handsets support SMS communication, the reason for the function listed, because some handheld devices only support text messaging communication, the function of real-time over GSM / GPRS / CDMA wireless data communication in real time lower, and sometimes because of text messages may be lost because the server real-time, unless the lease dedicated SMS server, and the overall data bandwidth of the communication process is very small. 9, GSM / GPRS / CDMA wireless voice communications: This function is mainly used for voice calls, after the second development to some extent after the alternative radio. 10, infrared data communication (IrDA): As the first short-range wireless data communication technology, this feature is currently in a variety of hand-held terminal is almost standard, except in some mobile phones and small handheld devices, most hand-held terminals with this feature. Note, however, is not known IrDA-enabled handsets are really supporting IrDA, a lot of hand-held terminal association only implementation of the IrDA physical layer specification is given, and not for IrDA protocol stack, the official in the IrDA standard is not recognized.
 11, infrared data communication (power infrared): Statute is power infrared standards issued by China Ministry of Electric Power, electrical equipment for data communications between the standard, the reason why this feature is mentioned here because a large number of meter reading are made in with this feature. 12, Bluetooth communication: Bluetooth communication function is the next generation short-range wireless communications technology, are mainly used in PDA and cell phone more. Other data terminals are also beginning to use the technology, the Bluetooth short-range communication of up to 10m, Bluetooth communication distance up to 100m, in the amount of data communication is not a great situation, Bluetooth technology can also replace 802.11B network.
 13, RS232 serial communication: as the basic data communication, basically all the hand-held data terminals are equipped with this feature. 14, RS485 Serial Communication: RS485 serial communication is used for long-distance technology, only a few special hand-held terminal with the function. 15, USB communication: USB communication technology for its communication rate, and so now many are beginning to use handheld devices, especially the PDA, its use is mainly with the PC a lot of data exchange. However, USB communication is not reciprocal, USB devices and sub-based devices from the device, the master device can only communicate with a slave, could not communicate with the master, only so very few handsets that can serve as a USB host device, but also as a USB from the device. Purchase in this area prone to errors, as long as both devices support USB 16,802.11 B: 802.11B mainstream technology for wireless local area network, the current pace of development is very fast, a lot of hand-held terminals have been equipped with this feature, with this enabled handsets in a relatively large range Zuwang with the PC, servers for data exchange, in a large enclosed space (such as factories, warehouses) for wireless data exchange. If the space is more than a wireless signal can cover the range, you can increase the number of nodes to solve.
 17, print: Some handheld terminal with integrated printing, can print documents. 18, handwriting recognition: hand-held terminal input and PC, IPC and other equipment than has been very weak, handwriting recognition can alleviate this problem, if you need a lot of text input, you must have this feature. 19, Chinese character input: no handwriting recognition for some of the handsets, if the Chinese character input, then this feature is essential, and should also consider the input method, spelling has been outdated, T9 relatively more receptive . 20, other functions, and some hand-held terminal with a number of other features, such as photographs, can be inserted CF card, SD card can be inserted, etc., need to select the user's needs.