UNIVERSAL SYSTEM FOR AUTOMATIC CONTROL OF RADIO-ELECTRONIC EQUIPMENT

V. M. Tanaseichuk, G. P. Pavlenko, V. M. Razin,
N. P. Baida, Ya. I. Kapitskii

(Presented by the scientific seminar of the Department of Computer Engineering)

At present there exist several principal approaches to the problems of constructing automatic control systems (ACS) [1].

The most promising are combined universal test systems capable of controlling complex radio-electronic objects of various kinds. The ACS described in this work provides sufficient universality of system application with a minimum amount of equipment. The proposed universal control system has the following technical characteristics:

1. Number of controlled parameters: up to 200.

2. Measured and controlled parameters:

a) DC voltage: 0–100 V;

b) AC voltage (amplitude and rms value): 0–100 V;

c) frequency of AC voltage and pulse repetition: 10–2000 Hz;

d) time interval: 0–600 sec.

1. Evaluation of controlled parameters according to the criterion “below norm — acceptable — above norm.” In addition to the evaluation, the percentage deviation of the controlled parameter from the nominal value within the tolerance range 0 ± 99% is issued.

2. Machine processing time for one parameter: no more than 300 msec.

3. Program input device: NB-1 magnetic drum. Information sampling rate for one controlled parameter: no more than 20 msec.

4. Output device: MP-16-9 printing mechanism. Printing speed: 25 lines per sec.

5. Number of programs for 200 controlled parameters, taking into account test control: 210.

6. The main equipment is implemented on semiconductor logic unified functional elements of the “Ural-10V” type. The switching unit is implemented on relays using magnetically controlled contacts.

The ACS operates in the following modes:

single check of all parameters;

Fig. 1. Block diagram of the universal ACS

manual selection of one monitored parameter with the possibility of continuous checking of subsequent parameters;

automatic checking of a group of parameters of the corresponding blocks of the object under test;

double measurement of one parameter with subsequent processing of the measurement results;

multiple measurement of one parameter (programmed).

In addition to the modes listed above, the following modifications are available:

ACS start mode from the monitored object;

ACS start mode from the object with a delay;

multiple measurement of a parameter at the operator’s choice.

In each of the indicated modes, provision is made for operation with printing and without printing.

The block diagram of the ACS is shown in Fig. 1.

The device for communication with the object is intended for:

bringing the parameters into a form convenient for conversion into digital code;

matching the monitored parameters with the ACS;

amplifying small signals to the required level.

Monitoring of the object parameters can be carried out with the object operating or not operating. If a nonoperating object is being monitored, then, in order to obtain at its output signals characterizing the response of the equipment, test signals must be applied to the input of the object (signal generators must be connected). The test signals from the outputs of the signal generators are switched according to the program from the input device through the switching block.

Analog-to-digital converters convert the analog signals arriving from the monitored radio-electronic equipment (REA) into the corresponding discrete (digital) quantities. From the outputs of the converters, the digital values of the measured parameters enter the computing unit (CU) for processing.

The operating program of the CU comes from the input device (ID). In accordance with the program, the CU performs the necessary arithmetic operations for each parameter. The result of the calculations is compared with the tolerances coming from the ID, the acceptability of the parameter is determined, and the percentage deviation within the tolerance range is determined as \(0 \pm 99\%\).

If the measured parameter falls within the tolerance range, the CU issues the signal “acceptable” and the percentage deviation. If the parameter does not fall within the tolerance range, the CU issues “below normal” or “above normal,” and in this case the percentage deviation is not determined.

Automatic recording of the test results is carried out by the output device with the aid of a digital printing mechanism. Continuous recording of control results is necessary for reliability studies, preventive maintenance, documentation, and the study of drift in the object’s characteristics.

The control unit (CU) ensures the time sequence of the operations of all parts of the ACS. The CU signals are also used to delay measurement of the response (output) signals for the duration of the transient process.

The program for testing the object, recorded on the NB-1 magnetic drum, is issued by the input device to the various ACS units. The rewriting device serves to enter the test program onto the magnetic drum. The rewriting device includes an FSM-3 photo-reading device and a PL-20-2 perforator. The test program is first placed on punched tape by the perforator.

To rewrite the program from punched tape to the drum, the “rewriting” mode is switched on at the control panel and the FSM-3 photo-reading device is started. After the test program has been transferred from the punched tape to the magnetic drum, the FSM-3 is automatically switched off.

For each parameter, the input device determines the order of connection of the test (input) signals, the response (output) signals, the ACS operating modes, commands to the object, tolerances, etc.

Monitoring of the operation of the ACS is carried out by the self-checking device (SCD).

Two types of self-checking are provided in the ACS:

hardware checking, which provides current monitoring of operation and information on malfunction of the main ACS devices;

test checking, which provides periodic verification of proper ACS functioning by means of a test program.

The CU and the ADC are equipped with hardware checking.

In the CU, circuit checking of clock pulses and modulo-3 checking of arithmetic operations are provided. In addition, to eliminate random CU failures, upon the first error signal the computation program is repeated. If the error is repeated, the signal “CU faulty” is issued.

In the input device, all circuits are covered by modulo-3 hardware checking, up to and including the outputs of the decoders.

The “analog-code” converter, in parallel with measurement, generates a modulo-3 key. The CU then generates the key of the measured quantity and compares it with the key coming from the converters.

When the keys being compared do not match, a “self-test passed” signal is generated.

Checking according to the test program provides monitoring of all the main units and blocks of the SAC in characteristic modes of their operation.

Test self-checking is carried out with the aid of reference signals. For this purpose the SAC provides two sources of reference voltage and frequency signals.

For test monitoring, the first 10 programs are recorded on the magnetic drum. According to these programs, reference signals are switched at the converter and compared with preassigned tolerances. Test monitoring is performed before the start of checking the controlled object and in preventive-maintenance mode.

The proposed universal SAC can find wide application for the automatic checking of all kinds of radio-electronic equipment in various branches of the national economy.

REFERENCES

1. N. P. Baida, V. M. Razin, Ya. I. Kapitskii, G. P. Pavlenko, G. P. Pavlenko, V. M. Tanaseichuk, “Systems for Automatic Monitoring of Radio-Electronic Equipment (Review).” The present collection.