RS-232 Port Research Articles

A compact multiparameter acquisition system for radon concentration studies

A compact device suitable to acquire and display, at the same time, radon concentrations in a given atmosphere, and the environmental parameters characterising the atmosphere, is presented and described. It consists of two main blocks: (i) a detection section including a set of sensors for measuring pressure, humidity and temperature, and a set of silicon surface barrier detectors mounted in electrostatic cells collecting the ionised radon daughters; (ii) a single NIM module featuring an eight channel 12 bit ADC and the linear electronics to shape the signals from the silicon detectors. The system is controlled by a computer via a RS232 port. The software, implemented in Visual Basic, allows to display the energy distribution of the pulses coming from the alpha detectors and to initialise and control all phases of the acquisition. The results of preliminary tests show the high reliability of the system.

THE TACQ COMPUTER PROGRAM FOR AUTOMATIC TIME DOMAIN REFLECTOMETRY MEASUREMENTS: I. DESIGN AND OPERATING CHARACTERISTICS

Despite the increased use of time domain reflectometry (TDR) for measurement of soil water content and bulkelectrical conductivity (BEC), there are few public releases of software for TDR system control. The TACQ program,under development since the early 1990s on a wide variety of soils, allows control of multiplexed systems supporting up to256 TDR probes. The program is DOS-based to ease creation of low-power, embedded computer systems; and toeliminate resource conflicts and timing difficulties inherent to multi-tasking, Windows-based operating systems. So that itcan be easily used in embedded systems, the program was written to run with as little as 640 kbytes of RAM and 1 Mbyteof expanded memory, and with a variety of graphics standards and CPUs ranging from 80186 to Pentium. Embeddedcomputer systems based on the PC-104 specification have been implemented using TACQ; and the program has beenintegrated into a supervisory control and data acquisition system (SCADA) for irrigation scheduling and control. Using aparallel port, the program controls multiplexers from both Campbell Scientific (Logan, Utah), and Dynamax (Houston,Texas); and it allows reading of probes in any user-defined order if using the latter. The user has complete control overmultiplexer address assignments, interconnection of multiplexers, and probe locations on each multiplexer; includingindividual settings for probe length, window width, averaging, distance to each probe, gain, and type of data acquired(waveform, travel time, apparent permittivity, water content, relative voltages for bulk electrical conductivity, or acombination of these). Interfaces to TDR instruments including Tektronix 1502 (modified), 1502B, and 1502C cabletesters are implemented through an RS-232 port. Concurrent temperature data may also be acquired (ComputerBoardsmodels CIO-DASx). System power control is implemented through the computers own power management capabilities,and through direct control of power to the TDR instrument and video subsystem where applicable, thus allowing creationof very low-power systems. The program is stable and suitable for use in environmental measurement systems that areunattended for long periods of time. Waveform interpretation methods are discussed in the second paper in this series.

Open, Interoperable Systems For Energy Control

The advent of solid state technology offered a means of using logic circuits to replace wire and relays. Electrical panels gave way to programmable logic controllers (PLC), which were programmed not with a screw driver but a data terminal. These PLC, first developed for the industrial process control industry, gradually migrated to the environmental control industry in the form of Direct Digital Control (DDC). If one wanted to interconnect DDC from different manufacturers, the incompatibilities between manufacturers led engineers to focus on linking separate systems with relays, custom gateways, and RS-232 ports. The problem is that these interfaces didn`t provide a detailed, seamless view into the different systems. The world of energy control systems has come a long way technologically since the advent of solid state controls. The availability of LonWorks control network technology, and of products like the LonPoint System that use this technology, opens the door to a new generation of energy control systems. Besides offering capabilities not previously available from control systems, open, interoperable systems offer higher reliability, greater vendor choices, and lower life-cycle costs than closed, controlled-based systems. The benefits to be reaped from these systems, both in terms of energy savings and lower system costs,more » are limited only by one`s imagination and vision.« less

Modeplus: a program for computer-assisted modal measurement

Point-counted modal analyses are an essential part of many petrological studies. Point counting is tedious work which delivers relatively small returns for the time invested. The introduction of a microcomputer to the system allows a permanent record of the point-counted data to be retained. In addition, it allows supplementary data to be accumulated on each grain measured (e.g. grain size and shape, and intergrain relationships, e.g. cumulus or intercumulus in an igneous cumulate rock). For the computer to be integrated properly into the system, it also must drive the mechanical microscope stage, which is done via an RS232 port.

New Products

Robotic Process Systems has developed a new five‐axis, fully automated and articulated ‘Cartesian Robot’ for component lead tinning. This system combines the dexterity found in robotic arms with high volume capacity. This allows very high production rates for virtually all types of components, from axial and radial leaded devices to fine pitch quad flat packs. In addition the system presents the customer with a large variety of options in terms of process stations. The open work bay can then be ‘configured to order’ according to individual process needs. Typical process stations include pre and post clean, de‐scale, DI rinse and pre‐heat/dry. The solder pot is a dynamic wave system which includes nitrogen inerting and automatic solder level adjustment. All functions are software controlled via a 486SX based PC, with easy to use, pull‐down type menus. Data transfer is facilitated through an RS232 port, and SPC data analysis program and networking are available options. A variety of quick‐change End Effectors are available to accommodate standard tooling or vacuum handlers.

Software for the Fermilab FASTBUS Smart Crate Controller

The authors report on software developed in support of the Fermilab FASTBUS Smart Crate Controller (FSEC). This software includes a full suite of diagnostics, support for FASTBUS Standard Routines, and extended software to allow communication over the RS-232 and Ethernet ports. The communication software supports remote procedure call execution from a host VAX or Unix system. The software supported on the FSCC forms part of the PAN-DA software system which supports the functions of front-end readout controllers and event builders in multiprocessor, multilevel, distributed data acquisition systems. >

Verbal computer terminal system

A telephonic data communications system provides verbal communication of data in remote computer systems. The major components of the systems are a plurality of channels and a data processor. Each channel includes a text-to-speech translator for translating digitally stored textual data into analogue speech signals corresponding to the verbal expression of the textual data; a telephone interface for establishing a telephonic connection with a user by detecting incoming calls and by initiating calls; and an RS232 port for accessing a data base in a remote host computer system. The data processor includes software for controlling the communications protocols used by each channel, whereby each channel emulates a computer terminal suitable for communication with the remote computer system connected to that channel, and software for extracting selected data from the data received from the remote computer system. This system enables one to telephonically receive data from a remote computer without the need for a computer terminal and without needing to reprogram the remote computer to communicate with the telephonic data communication system.

A microprocessor-based semiconductor solar radiometer

The photocurrent produced by a silicon PN junction is used as a solar radiation transducer. It has high and linear sensitivity in the main part of open sunlight spectrum. Using a commerical device as sensor, a low-cost solar radiometer can be constructed. The photocurrent produced is electronically tailored to store solar radiation data in a microprocessor-based data acquisition system. This portable instrument can be used in remote sites and substitutes solar monitor, integrator and data-logger equipment. The data can be transported by a RS-232 port or in a nonvolatile static RAM card, interfaceable with personal microcomputer.

Development and evaluation of a dual-pump microcomputer-based closed-loop arterial pressure control system.

Hypertension after cardiac surgery is common and is associated with increased morbidity. It is usually managed by the infusion of short acting vasodilators. The use of a closed-loop computer system to control the infusion of a vasodilator has been shown to compare favourably with manual control. We have developed a closed-loop system for the ATARI 1040ST microcomputer to control arterial pressure by the simultaneous infusion of two vasodilators. The control program is based on a proportional-integral-derivative algorithm which has been adapted to allow control of two IMED 929 infusion pumps from one RS-232 port. All communication between the user and computer is carried out with a 'mouse', thus increasing acceptability of the system to ward staff. Cardiovascular data are collected on-line from the patient monitor via a custom-built analogue to digital convertor. This system was used to study glyceryl trinitrate and sodium nitroprusside in 24 patients requiring vasodilators after cardiopulmonary bypass. The study showed that in 14 of the patients hypertension was controlled by GTN alone and 10 required supplementary SNP. We have demonstrated that this dual-pump automatic arterial pressure control system is a satisfactory and safe method of administering two vasodilators simultaneously. It is suitable for both routine clinical and research uses.

Portable software for connecting remote microcomputers and a central minicomputer

A number of programs which allow communication between remote microcomputers and a central computing centre are described. The software is written in BASIC for the microcomputer (an Equinox) and in PASCAL for the min-computer (Nord 100). The requirement for the microcomputer to run the software is that it is CP/M-based and has a spare RS232 port. Data is transferred in blocks of 40 byte to the remotes sites via modems through the telephone lines. The datarate is 300 baud. Examples of the communication software are given.

A simple IBM I/O Selectric typewriter controller

A simple inexpensive IBM I/O Selectric typewriter controller is described. The board plugs into an RS-232 port and enables letter-quality output. Computers with editing capabilities can therefore be used as word processors for as little as $35, about 8 h of labor, and the cost of the typewriter. The controller is a firmware-governed microprocessor, and as a result, it is easily tailored for special applications. Hardware and software are discussed.