Connecting Serial Devices

Sometimes the connectivity to simple instruments, like balances or pH-meters, poses special problems mainly due to the following facts  

To connect software to a serial device, the following components are reqnired  

To ensure data integrity as required by regulatory authorities, the following information has to be present at the balance location  

User identification in a typical SDS scenario is performed by the target software. 

Sample and batch identification can be performed either at the balance using a bar code reader or a keyboard input or by running the target software on a mobile device, like a tablet PC. 

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USB Acronym for Universal Serial Bus. A technology used to connect peripheral devices to a computer. Each USB channel will support 127 devices and has a total transfer rate of up to 12MBps. 

Most of these devices communicate via serial ports that is, a computer, or a device server, is required to connect the device to the compnter network. 

A serial device server connects the serial port to the network. The device server is a piece of hardware that provides an IP address, thns making the serial device act like a compnter in the network. Conseqnently, no additional compnter is needed, and the device can be plngged directly into the network. Some device servers optionally provide a virtnal serial port, which makes the serial device behave like a computer with a standard COM port. 

Serial Device Support (SDS) is a concept that supports the data transfer between applications and a serial device connected to the network. It allows data to be received from serial ports, whether they send streaming (continuous) or single data. 

The first functional part of the application will be communication part, which provides setting parameters of the bluetooth module, serial port, diagnostics of communication and organization of the serial line protocol. For the Bluetooth module BluesenseAD connection a few basic steps are needed first. The computer, to receive data from BluesenseAD modul, must also be equipped with a Bluetooth device. In the case of desktop computers, it is needed to use Bluetooth cards or other USB donge device, for laptops (netbooks), the situation is much easier because they already contain the standard Bluetooth. Bluetooth driver installation and configuration follows, the driver also make sa virtual serial port accesible, which provides the communication. After these steps of pairing between devices will take place and BluesenseAD is connected to the computer. This procedure is required each first time you connect any device, after its successful completion application can communicate with. 

Fig. 1. Electronic medication event monitor in the process of communicating stored data from monitor to computer. The transfer occurs without wire connection between the inverted monitor and the communications interface device, which transfers data to MS-DOS-based computers via serial port. A second medication event monitor, with a somewhat larger container size, stands nearby. (Copyright, 1994, APREX Corporation reproduced with permission.)...

There are two DSP-32s per processor module . The master (with external memory) is connected to the serial lines going to and from the crossbar switch. The slave is connected to external I/O devices such as A/D and D/A converters. It is... 

Bolz S, Gotzenberger M, Knorr R, Lugert G, Siemens AG. Device and method for equalising the charge of serially connected capacitors belonging to a double layer capacitor. WO patent /2005/074092. 

Terminals tied to a computer through RS232C or 20 mA connections are an example of loosely coupled devices. The serial ASCII transmission of data is adequate for applications where dynamics or animation are not a factor (the VT125 and GIGI can be used to a only very limited extent here). This approach has been used in both classes of equipment, our own terminals for example in raster work and Tektronix or IMLAC terminals in vector systems. 

The RD-02 is a totally independent probe. It does not need control from the area centre or any other device. It measures the dose rate and saves the measurement data in its memory. There is space for 80 measurement results. These results can be sent out through the RS-232 serial connection on request. The excellent linearity in the whole dose rate range is accomplished by the Time Interval Method (TIM) developed by Alnor in the early 1980s. This method calculates dose rate from the time interval measured between pulses, thus cancelling the need to take the dead time of the GM-tubes into account. Calibration factors are saved in the RD-02 s EEPROM memory. Probes can easily be removed and sent to a calibration laboratory. Thus, there is no need for on-site calibration. 

In the next section, you learned how to get the data into and out of the computer using the various interfaces commonly found on computers. Some of these interfaces include serial, parallel, USB, and FireWire. These interfaces connect input and output devices to the computer and provide the pathway for data transfers. 

Occasionally, networks use RS-232 cables (also known as serial cables) to carry data. The most classic example is in older mainframe and minicomputer terminal connections. Connections from the individual terminals go to a device known as a multiplexer that combines the serial connections into one connection and connects all the terminals to the host computer. This cabling system is seen less and less as a viable TAN cabling method, however, because LAN connections (like twisted-pair Ethernet) are faster, more reliable, and easier to maintain. 

The next most popular peripheral connection method is parallel. Parallel connections transfer data 8 bits at a time as opposed to 1 bit at a time (as serial connections do). The most common peripheral connected via a parallel connection is a printer. Hence, parallel ports are often called printer ports. Additionally, newer parallel ports can connect devices like scanners and Zip drives to computers. Unfortunately, this doesn t work as well as other types of connection methods such as USB work because the parallel connection wasn t designed for connecting devices other than printing devices. Parallel was only designed to connect one peripheral at a time. 

In the last few years, a high-speed bus has been developed specifically for peripherals. That bus is the Universal Serial Bus, or USB. The serial bus could only connect a maximum of two external devices to a PC. USB, on the other hand, can connect a maximum of 127 external devices. Also, USB is a much more flexible peripheral bus than either serial or parallel. USB supports connections to printers, scanners, and many other input devices (such as joysticks and mice). 

The Universal Serial Bus, or USB, is a relatively new connection device. Which of the following are characteristics of USB ... 

D. The Universal Serial Bus (USB) connects up to 127 external devices, supports most peripherals (including printers, scanners, digital cameras, mice, etc), and provides a high data transfer rate. 

Automated sample preparation can be accomplished by using a batch or a serial approach. In the batch mode, multiple samples are prepared and then transferred to the analytical instrument for measurement. In the serial mode, samples are prepared one at a time and the SP device is connected (integrated) with the analytical instrument only. 

A counter for measuring changes of the resonance frequency can be a common device widely used in electronics. The resolution of frequency should be at least 1Hz within Is interval, the upper limit of frequency should be near 50 MHz. An important feature is the possibility to connect to a personal computer to allow on-line monitoring of the affinity interaction the easiest way is through the standard serial (RS 232C) and USB ports, the GPIB option will require a special interface... 

Fig. 3. Sketch of the hardware and software system used in the author s laboratory to investigate the electrode kinetics of electrochemical reactions. D.A.C are digital-to-analogue convertors, F.R.A. is a frequency response analyser, A.D.C. are analogue-to-digital convertors (used to switch devices), D.P.M is a panel meter, and NTWK is the university network serial connection to an Amdahl computer. The units I are the appropriate interfaces.

Data rcprcsomccomputer modem, which is a device for transmitting data between computers by telephone over a single conductor (and a common connection). 

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