Interface control board

Set up an interface control board to review and evaluate technical interface data. 

The autosampler system is controlled by an IBM computer system, as is the series of pumps for the cell and the sample wash pot. An Archer single board computer (Sherwood Data System) programmed via ASCII strings along an RS232 interface, controls the pumps and the autosampler, setting up a stable representative sample which is then measured by using the standard Solomat software and hardware. 

When 8-bit microprocessor-based computers became available, we decided that such a computer, even though slower than minicomputers, would be adequate to operate the OMA and our interface controller with the ultracentrifuge. We now have in the system an Altair 8800 computer with 28K of memory (MITS, Albuquerque, NM), a hard-wired arithmetic board and two minifloppy disk drives (North Star, Berkeley, CA), a 700 ASR Terminal (Texas Instruments, Dallas, TX), and a 7202A Graphic Plotter (Hewlett-Packard, Palo Alto, CA). Appropriate software, written in Basic, has been developed to collect intensity data from the OMA automatically and also to treat and plot the data at the end of the experiment. Details of the system and software will be published elsewhere. We also have an improved illumination system with a 200 W Hg-Xe arc lamp and a Model H-20 monochromator with a holo-... 

Most fuel cell systems have a CPU/controller board with options for remote hardline or wireless control by logic or computer interfaces. Other types are a little less exotic, but usually have some type of micro controller. Safety functions such as leak alarms and shutdown are included in most systems. 

The status of the actuated equipment is transmitted by the ILC s over the data highway to be displayed on the Main Control Board. The actuation logic is implemented by three redundant microprocessors and the actuation signals are voted in a 2/3 Logic in the power interface boards. Built-in automatic tester is provided for each ILC. 

To implement Ml image process control, an IR line scanner is placed at the oven exit, scaiming across each blank as it leaves the oven. The forward movement of the part, combined with the fast response of the line scanner, provides the Ml thermal map to the computer. A Ml statistical control chart is software-generated, based on mean temperature and standard deviation over the entire surface. The oven heater is zoned and the computer interfaced to a relay control board with one relay managing a set-point controller for each zone. The statistics for each control zone are calculated based on the corresponding section on the part, and a closed-loop statistical process control algorithm is implemented. The result is seen on the 3D strip map presentation shown in Fig. 10.8(b). The color hues indicate temperatures in accordance with the scale at the left. The control level temperature is about 300°F. 

The controller can accept three direct memory access requests DCHRl, DCHR2, coming either from the Display Board or from Collecting Interface/Miscellaneous Boards. The third one, DCH3, might be used by the boards inserted into the option board slot. 

The control of the airborne sound location system, the coupling monitor and the real-time evaluation of all signals, including the echo indications from the ultrasonic instrument, is carried out on two additional boards in the PC. The graphic user interface (under Windows 95), including online help, enables an easy operation of the system. The evaluation program links all echo indications in real time with the probe position and displays them in a graphic repre-... 

The Mass Spectrometer Module houses the vacuum system, capillary interface assembly, and ion-trap mass spectrometer in approximately half of the module. Also included are the reagent gas and calibration gas subassembly (a temperature-controlled housing that ensures consistent gas pressures). The other half contains the electronic printed circuit boards, power supplies, and instrument control computer. 

A microcontroller board for sensor read-out was developed in collaboration with AppliedSensor (Reutlingen, Germany). This board provides the power supply and the necessary reference voltages and currents to the sensor chip. The sensor chip is mounted on a socket and connected to the microcontroller. The microcontroller provides a set of commands for programming and reading the on-chip registers, controller parameters and sensor values. The microcontroller also manages the data transfer between the f C interface of the microchip and a serial RS-232 interface for external read-out via a PC. The data stream is continuously read out in the measurement mode. Each data set contains the temperature of the microhotplate, the chip... 

The microcontroller board, which is connected to an RS-232 interface of a PC, and a 5.5 V power supply, is all that is needed to control and operate the sensor system. 

Initially, the control units were quite clumsy and offered uncountable manipulation options. It was often the case that only physicists were able to handle and use them. With the Introduction of PCs the requirements In regard to the control units became ever greater. At first, they were fitted with Interfaces for linkage to the computer. Attempts were made later to equip a PC with an additional measurement circuit board for sensor operation. Today s sensors are In fact transmitters equipped with an electrical power supply unit attached direct at the atmosphere side communication with a PC from that point Is via the standard computer ports (RS 232, RS 485). Operating convenience Is achieved by the software which runs on the PC. 

A test system, controlled by personal computer (PC), was developed to evaluate the performance of the sensors. A schematic of this system is shown in Figure 3. The signals from the sensors were amplified by a multi-channel electrometer and acquired by a 16 bit analog to digital data acquisition board at a resolution of 0.0145 mV/bit. The test fixture provided the electrical and fluid interface to the sensor substrate. It contained channels which directed the sample, reference and calibrator solutions over the sensors. These channels combined down stream of the sensors to form the liquid junction as shown in Figure 1. Contact probes were used to make electrical connection to the substrate. Fluids were drawn through the test fixture by a peristaltic pump driven by a stepper motor and flow of the different fluids was controlled by the pinch valves. 

Many manufacturers have used the capabilities of on-board processing power to provide a user friendly interface for the operator. This results in a host of useful (and some not so useful) features for the analyst, and allows the pump to be remotely controlled by a computer, or another component of the HPLC system. This can facilitate method development for instance, as the pump can be programmed to change automatically the composition of the mobile phase after a number of runs. It does this by changing the proportion of time that it draws from each of a number (up to four) of solvent reservoirs, that can contain diflferent modifiers or buffers. Computerisation of pumps can also allow unattended runs to be performed with a greatly increased measure of confidence. In a networked... 

A floppy controller is not a complicated device. The early controllers were large expansion boards that usually contained an Intel 8272 or Zilog 765 controller chip. As this book is being written, you can buy a card that contains the floppy controller, two serial interfaces, parallel and game interface ports, and disk interface for about 35. 

In addition, because the controller was integrated into the same assembly as the drive, the only board that needed to be installed in the computer was an adapter that converted signals between the motherboard and the drive/control-ler. The board is normally called a pass-through or paddle board. (This board is often, incorrectly, called a controller. The term is incorrect because the paddle board is often integrated with a floppy controller, two serial ports, a game port, and a parallel port. In fact, this combination is normally called a multifunction interface board.) With some of today s systems, the IDE adapter is integrated into the motherboard. 

The final component in the laser printer we need to discuss is the printer controller assembly. This large circuit board converts signals from the computer into signals for the various assemblies in the laser printer, using the process known as rasterizing. This circuit board is usually mounted underneath the printer. The board has connectors for each of the types of interfaces and cables to each assembly. 

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