GB/T 5444-1985 Test methods for technical indicators of user signals in automatic telephone switching network
Some standard content:
National Standard of the People's Republic of China
GB/T5444—1985
User signaling for automatic telephone switching network
Technical specification test methods
The test methods for the technical specificationsof subscriber line signallingfor automatictelephone switching network
Published on October 30, 1985
National Bureau of Standards
Implemented on June 1, 1986
National Standard of the People's Republic of China
User signaling for automatic telephone switching network
Technical specification test methods
The test methods for the technical specificationsof subscriber line signallingfor automatictelephone switching network
UDC621.395.66
:621.391.8
:621.317.08
GB/T5444—1985
This test method is based on GB3378—1982 "User Signaling Method of Automatic Switching Network of Telephone", and is applicable to the vertical and horizontal (or quasi-electronic) switching office. The test content includes*:
Technical indicators of dial (or key) pulse reception; a.
Technical indicators of signal transmission of multi-frequency key telephone, b.
Technical indicators of signal reception of multi-frequency key signal.
1. Technical index test of pulse reception of dial (or key) 1.1 Index
Pulse speed: 10 pulses/s;
Pulse intermittent ratio: 1.6±8:3:1;
User loop resistance is not greater than 20002 (including telephone resistance), and the feeding current is not less than 18mA; User line insulation resistance is not less than 20000Q; d.
User line capacitance is not greater than 0.7μF
1.2 Test method
1.2.1 Pulse speed and intermittent ratio reception index test Connect the test circuit according to Figure 1. Connect the dial pulse generator to close the user loop and occupy the user register. Control the dial pulse generator to send numbers and observe whether the user register receives numbers correctly. The number sending digit length and number combination should be selected according to the specific equipment conditions to ensure that all stored number circuits have been tested. The pulses sent by the dial pulse generator should be tested in nine combinations of pulse speed 8, 10, 14 pulses/s, and intermittent ratio 1.3:1, 1.6:1, 2.5:1. * The pulse speed and pulse intermittent ratio indicators of the dial telephone specified in GB3378-1982 have been tested in GB1492-1979 "Telephone Test Methods", and this test method will not be repeated.
National Bureau of Standards 1985-10-30 Issued
1986-06-01 Implementation
GB/T5444-1985
2ac -gt2
2-—1.0±0.1μF
R-—100±52:C
Then, connect the test circuit according to Figures 2 and 3, and repeat the above test process respectively. 230.902
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R—100±52;C—1.0±0.1μF
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Rongshangfu
GB/T5444—1985
R—100±52,0-—1.0±0.1μF
Jinshanghua
For the exchange that has been put into use, the power supply voltage during the test should be recorded. The exchange that has not been put into use should be subjected to limit testing, that is, in the tests of Figures 1 and 2 (the longest user line), the power supply voltage is limited to -56V; in the test of Figure 3 (the shortest user line), the power supply voltage is -66V.
1.2.2 Feeding current measurement
Connect the test circuit according to Figure 4, keep K5 and Ks open, and close K, K2 and K3, K4. Use a telephone (select a dial telephone or a multi-frequency key telephone according to the circuit being tested) to call. After the called party is connected and the called party picks up the phone to answer, disconnect K and K2, close Ks and K, and finally disconnect Ks and K4. The indications of the DC milliammeter mA1 and mA are the feeder currents of the calling and called users respectively. The feeder voltage value of the machine room during the measurement should be recorded. If it is not -60V, the measured current value should be converted into a -60V feeder current value according to a linear relationship, and the value should not be less than 18mA. 2200-,5
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K1, Kz, Ks, K4Ks, Ke-switch or other circuits with the same function mA1, mAz DC milliammeter 3
1.2.3 Instrument requirements
GB/T5444-1985
DC milliammeter: should be able to measure 1100mA DC current with an error of ±2.0%. Number plate pulse generator: five types of pulse speeds: 8, 9, 10, 11, and 14 pulses/s, and five types of pulse intermittent ratios: 1.3:1, 1.4:1, 1.6:1, 1.8:1, and 2.5:1. Various pulse speeds and pulse intermittent ratios can be combined arbitrarily, the intermittent ratio error does not exceed 2.0%, and the pulse period error does not exceed ±2.0%. The number plate pulse generator should be able to control the number of pulses sent. If the number can be sent automatically and continuously, the interval between pulse trains should not be shorter than 500ms. The pulse speed and pulse discontinuity ratio of the dial pulse generator should be measured in accordance with the provisions of Section 4.4 of GB1492-1979 "Telephone Test Methods".
2 Technical indicators of multi-frequency key telephone transmission signal test 2.1 Indicators
2.1.1 Transmission frequency
The frequency combination used by the multi-frequency key telephone is shown in Table 1, and the frequency deviation does not exceed ±1.8%. Table 1
Low frequency group Hz
High frequency group Hz
2.1.2 Transmitting level
When there is a 3dB attenuation buffer
Low frequency group: -10±5.5dBm
High frequency group: -9±5.5dBm
11 (*)
The difference between the high and low frequency levels of a signal is not greater than 6.5dB2.1.3 Distortion
The total distortion caused by harmonics and intermodulation is at least 20dB lower than the fundamental wave level. 2.1.4 Signal limit duration
The signal transmission duration is greater than 40ms/bit.
2.2 Test method
2.2.1 Signal transmission frequency, level, distortion measurement Hs
12(*）
1633 (spare)
Connect the measurement circuit as shown in Figure 5. Press a number key without restoring, use the audio frequency selection level meter to select the main transmission signal frequency* and level, and then select various harmonics and intermodulation distortion signal frequency levels, and calculate the total distortion according to power superposition. After the selection and measurement, restore the pressed number key. Repeat the measurement of the signal frequency, level and distortion when pressing each number key under each feeding condition. Then connect the measurement circuit as shown in Figure 6 and repeat the above process.
If the phone does not have a 3dB buffer attenuation, the transmission level should be the low frequency group: -7±5.5dBm
*If the transmission single frequency can be controlled, the frequency can be measured by a frequency meter. 4
High frequency group: -6±5.5dBm
Technology
GB/T5444—1985
1337±(0g
712:70
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HI = 5
1: 0,dμE
Alignment point electricity
Key selection pre-level state
2.2.2 Signal transmission limit duration
GB/T5444—1985
According to the test method of the multi-frequency key telephone standard, the stable and normal AC signal duration measured should be greater than 40ms. 2.3 Instrument requirements
DC power supply: output voltage -1～-70V, continuously adjustable. Audio frequency selection level meter: balanced input, high impedance (greater than 10kQ), frequency selection range The range is above 50Hz10kHz, the bandwidth of the frequency selection is 8Hz (△3dB), the measurement level range is -60~+20dB, and the internal self-distortion attenuation should be greater than 60dB. 3.3 Technical indicators of multi-frequency key signal reception for bureau 3 3.1 Indicators wwW.bzxz.Net
3.1.1 Receiving frequency
The nominal frequency combination is shown in Table 1. Reliable reception is possible when the frequency deviation is not greater than ±2.0%, and no reception is guaranteed when the frequency deviation is not less than ±3.0%. Reception is not guaranteed when the frequency deviation is greater than ±2.0% and less than ±3.0%. 3.1.2 Receiving level
When dual-frequency input, the single-frequency receiving level ranges from -4 to -23dBm, and the dual-frequency level difference is within 12dB. When dual-frequency is working, the single-frequency non-operating level is -31dBm.
3.1.3 Receiving signal duration
Signal duration receiving range is 30~40ms/bit. 3.2 Test method
Connect the test circuit according to Figure 7, establish and maintain the connection between the main distribution frame a and b lines to the user transceiver and the multi-frequency key receiver, and cut off the dial tone.
a. The input signal frequency takes the various combinations of the unshaded part in Table 2, and the input signal level takes the combinations of 1 to 6 in Table 3. The control switch K is closed for 40ms and then disconnected, and the user transceiver should receive the number correctly. b. The input signal frequency takes the various combinations of the shaded part in Table 2, and the input signal level takes any combination in Table 3. The control switch K is closed for 40ms and then disconnected, and the user transceiver should not store any number. c. Input signal frequency is any combination listed in Table 2, input signal level is combination 7 in Table 3, control switch K is closed for 40ms and then disconnected, user register should not store any number. In Figure 7, the signal level should be monitored at points C and D using an audio frequency selection level meter (balanced 600Q) before switch K is closed. Attention should be paid to disconnecting the audio frequency selection level meter before closing switch K. 6
GB/T5444—1985
Table 2 Technical indicators for receiving multi-frequency key signals for local use Test signal frequency combination H
1551209 12 12429
747447147 L667 1521258+1600182716686826
Signal level
Frequency group
High frequency group
Low frequency group L
GB/T5444—1985
Technical indicators for receiving multi-frequency key signals for local use Test signal level 2
E1, E2 audio oscillator; K-Switch that can automatically control the closing time, each closing time is 400-ms3.3 Instruments used and requirements
Audio oscillator: balanced output, frequency range 300～3kHz, output level range -35～+20dB, output impedance 600Q (or 0Q).
Audio frequency selection level meter: balanced input 600Q, frequency range 50Hz～10kHz, measurement level range -60～+20dB. Additional remarks:
This standard was proposed by the Ministry of Posts and Telecommunications of the People's Republic of China and is under the jurisdiction of the Telecommunications Transmission Research Institute of the Ministry of Posts and Telecommunications. This standard was drafted by the Telecommunications Transmission Research Institute of the Ministry of Posts and Telecommunications and the 738th Factory of the Ministry of Electronics Industry. The main drafters of this standard are Huang Shiliang, He Guopai and Li Tiancai. 8
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