Existing test methods of communication power supply system for manual testing, not only to connect many cable operators and equipment, but also to each value of artificial judgment system, its test time is long, repeat the test result of poor consistency, human factors, the test is not stable, it is not easy to test data archive, etc., therefore, the performance of the power system can not get enough protection,
Namisoft proposed testing method, first start the pneumatic device to realize automatic test port connection, it will save the human connection; Then based on LabWindows/CVI development environment, the use of GPIB card control all kinds of instruments and equipment, with the power supply system by means of the TCP/IP communication dialogue, this method can quickly and reliably finish each parameter test, so as to improve the efficiency, and can automatically archived data,
One is
1. 1 introduction of LabWindows/CVI
LabWindows/CVI interactive C language development platform, it will be powerful, flexible to use C language platform and used for data collection and analysis and display of the measurement and control of professional tools organically, take advantage of its integrated development environment, interactive programming method, function panel and rich greatly strengthened the function of the C language library function, is familiar with C language written test system development and design personnel, automatic test environment, data acquisition system, process monitoring system and other application software provides an ideal software development environment,
Virtual instrument technology is a new generation of instrument technology, which is developing rapidly in recent years, its essence is to use a computer to simulate the functions of traditional instruments, LabWindows/CVI is the development of virtual instrument application software tools, and other virtual instrument development tool, its main features are:
(1) the LabWindows/CVI to powerful, the most popular C language as the foundation, generally the programmer does not need to take time to learn other computer language, so as to save development time,
Edit mode (2) a friendly interface, flexible application in program design tools can be convenient and program design, easing the burden on programmers,
(3) a variety of powerful software package greatly enhance the performance of LabWindows/CVI, the software includes interface function library, signal processing function library, such as Windows SDK,
1. 2 GPIB bus technologyGPIB (General Purpose Interface Bus) is called a General Purpose Interface Bus, was among the first to put forward a kind of Interface instrument by HP company standard HP (IB), in 1975 was improved as IEEE485 standard, the current agreement is 488. 2, GPIB Bus is widely used in the automatic test system for an x and Bus standard, is specially designed for instrument control applications, it is a kind of Bus is used to connect equipment, computer, voltage meter, signal generator, oscilloscope can be connected through the GPIB Bus, such as a function of system,
The characteristics of the system is: modular structure, removable, easy to reconstruction; Microprocessor controller can be a computer, or simple program; Reliable data transfer, the use of flexible, low cost, it is because of the above characteristics, GPIB is widely used in computer control was carried out on the test equipment, computer and communication between computers, and other electronic devices to control,
LabWindows/CVI GPIB function library can realize opening/closing of GPIB equipment, bus configuration, I/O read and write, GPIB equipment control, bus control and panel control function,
1. 3 TCP/IP communication technology
Most widely used in Internet network protocol for TCP/IP protocol, TCP protocol is TCP/IP protocol concentrated belonging to the transport layer transmission control protocol (TCP), IP protocol is the foundation of Internet networks belonging to the network layer protocol, IP protocol provides reliable and do my best, connectionless data delivery service, and formed the basis of Internet, network data transmission, TCP protocol based on increased connection management and confirm retransmission mechanism, such as the higher application provides a connection-oriented, reliable transport service,
In LabWindows/CVI available TCP function library for network transmission, are involved in every connection to the server and client,
The TCP server can send the client application through the network or from the client application receives data, TCP client can sends a connection request to the TCP server application and receives data from the server, the server after registration is waiting for the client connection requests to it, and customers can only sent the already existing server connection request,
2 system hardware designNamisoft provide communications equipment composition of dc supply system as shown in figure 1, the system input for ac 220 v, on the one hand to communication equipment power supply, rectifier to the battery charging again on the other hand, to supplement lost power due to partial discharge battery, controller for monitoring system of the state, dc main distribution frame connections and convert the dc power supply system of the rectifier and battery to power equipment, communications equipment power supply batteries used to ensure uninterrupted power supply,
Dc power supply system of figure 1
Main components of the power system test by a computer, a GPIB card, data acquisition unit, dc power supply, load test fixture and and other components of the system under test, as shown in figure 2,
Figure 2 power system test hardware structure diagram
Data collector can be configured to 20 to 120 channels, six and a half, resolution 250 channel/seconds scanning rate, 50 000 readings storage, basic dc accuracy of 0004%, can measure the ac/dc current, resistance, frequency and period, and the thermocouple, heat resistance and the temperature of the thermistor with dc and ac voltage, standard GPIB and RS232 interface, in this test system, it is mainly used to control relay, channel switching and measuring voltage,
Dc power supply is mainly used to simulate the function of the battery, battery over-voltage, under voltage and low voltage power,
Inside the test fixture by relay team, the alarm light and pneumatic device, a pneumatic device used for automatic connection test endpoints, relay switch is mainly used for different set of test equipment, and switches, four set of traffic lights, warning lights for viewing different system alarms, such as breaking alarm, fuse alarm, temperature alarm and so on,
Power supply under test system consists of two modules, a controller and a dc power distribution frame, module for rectification, the 220 V ac to 54 V dc voltage controller is used to set the system, monitoring system, dc distribution frame to module and controller, it is equipped with automatic air circuit breaker, contactor, fuse and other parts, for different capacity of the load distribution of electrical energy, when abnormal dc supply, produce the alarm protection,
Alternating current (ac) 220 VAC for input power supply module,
Load to simulate communication equipment, used to provide AC power and battery power when the load of the system, the system test load setting of 20 A,
3 Namisoft system software development
System software with Labwindows 8, 5 for the programming language, can run on Windows XP, Vista and Windows 7,
3. 1 test process
According to the test requirements, first of all set a reasonable test process, as shown in figure 3, can be divided into three parts, the first part is the self-inspection, the second part is the AC part, the third part is the DC DC parts (battery),
(1) the introspection, the operator will be placed in a power system under test fixture, undertake self-checking, first of all devices in the system reset and initialize, detection systems the state of the power supply is normal,
(2) the AC part, after self-checking by input AC 220 VAC, first in this section, first measurement system when no-load output voltage, current, system status, after load voltage and current measurement system, and whether current detection module, load switch to the battery terminal, then measuring the battery voltage and current, and then perform some alarm test, including dc overvoltage, undervoltage, fuse alarm, circuit breaker alarm, temperature alarm and so on,
(3) the DC part, after the test battery power system output voltage, current, AC alarm, battery over-voltage alarm, under-voltage alarm, low pressure shutdown functions,
3. 2 Namisoft core code parsing
Below is a list of a few key test code,
(1) the GPIB communication code
GPIB/GPIB - 488. A total of 10 children, including 2 function library Open/Close subclass, respectively, the Configuration subclasses, subclasses, I/O DevICe Control subclass, Bus Control subclass, BoardControl subclasses, Callbacks subclasses, LOCking subclasses, Thread - Specific Status subclasses, GPIB - 488. 2 subclasses, and the test method is mainly used in the GPIB - 488. The two subclasses of function to realize GPIB communication,
FIG. 3 flow chart of test
SendIFC (0);//for all GPIB device initialization,
Send (Board _Index, address, buffer, Byte _Count, EOT_Mode);//send the address and write data, GPIB Board_Index said name, address, address said instrument buffer to send information, Byte _Count said bytes sent information, EOT_Mode said delivery mode,
The Receive (Board _Index, address, buffer, Byte _Count, Termination);//receiving address, read the data from the GPIB equipment, said Termination data transmission terminators,
(2) the TCP/IP communication code
The power system can be through the network port network communication, internal information to read system,
Due to read system information belongs to the client to the server connection, so make sure the communication as part of the client, and the TCP server connection, we must get the server name or IP address and server port number,
ConnectToTCPServer (& amp; ServerHandle, server - PortNumber, serverName, ClieNTCallback, callback - Data, the timeout);//registered TCP server, parameters serverHandle said the connection handle, parameter serverPortNumber and server - said the Name of the server port number and Name, ClientCallback and callbackData said TCP callback functions and callback data, parameter timeout timeout limit,
ClientTCPWrite (portHandle writEDAta, data - the Size, the timeout);//send data to the server, parameter writeData indicates the data sent to the server, the dataSize said the size of the data block,
ClientTCPRead (portHandle, buffer, dataSize, timeout); Said//read the data from the server, and parameters of the buffer to store the data you read from the server block buffer,
DisconnectFromTCPServer (serverRouteHandle);//cancellation of the TCP server,
(3) HP34970 control code
Because HP34970 provides the functionality of the program panel greatly facilitate the programming, we only need to call the library function instruction, tests need channel switching can be realized and quantity,
Hp34970_relay_Operate (1, 6, ON);//6 closed control relay,
Hp34970 _relay_Operate (1, 6, OFF);//6 open control relay,
Meter _Measure (METER1);//read voltage value, table 1
Switch_lFMux_DMM (101);//switch testing channel to MUX101,
4 total knot
In the process of software debugging also appeared some problems, through the analysis, were resolved:
(1) to place a large number of numerical variable in C file, cause the program readability, maintainability is poorer,
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