MOTOROLA 950i Analogy Radio and WDS 2710 Digital Data Radio:Performance and Technical Indicators Comparison Test Report

I、Introduction:

Xi'an Urban Water Supply and computer-aided dispatch system to be used 220 ~ 240MHz frequency band wireless data transmission. For the formation of efficient and reliable wireless data transmission system, water company in Shenzhen Huaxia Sheng Xian (WDS digital radio), MOTOROLA MOSCAD RTU, 950i data radio and the Australian company's Beijing office ACTION (ACTION RTU) under the coordination of October 2002 10 --- 17 more tests done on-site in Xi'an.
At present the company's selection on the main RTU consider the following two products:
1 U.S. MOTOROLA's RTU
2 Australian ACTION CONTRON RTU's RTU
Ancillary data transmission stations mainly in the following two models:
1 U.S. MOTOROLA's GM950i analog data radio
2 Shenzhen Huaxia Sheng's 2710C digital data radio
These two different radio works: 2710C uses a direct digital modem; and GM950i uses FM analog modem chip car radio plus restructuring. Therefore, the performance of the two is a significant difference, the price is also quite different.

II、Test purpose:
1 FM transmission on FM in the applicability of this project: the project-specific site in the environment, the way it can be done with the FM data transmission functions;
2 the reliability of wireless communication: the integrity of data transmission, accuracy;
3 anti-jamming capability: the outside world or man-made electromagnetic interference in the case of radio interference data transmission capacity;
4 polling cycle length: Two radio stations for the same data several times the amount of data transmission, the transmission time of the actual occupation of the channel to compare;
5 Single-point data transfer conversion time and the relationship between the radio data rates: in a poll of the data transmission time occupied by the percentage of time occupied;
6 Radio stations the ability to work long hours;
7 Large amount of data under high-load working condition and the stability of the radio data transmission accuracy: in the southern suburbs have been built between the water and the              company's dispatch center for frequent transmission of large amounts of data, comparing the two stations and data stability correctness;
8 Using two different radio data may be achieved relay, network diagnostics.

III、Test Content:
(I)The RTU MOTOROLA and 2710C, respectively, with GM950i radio stations
1-point distance data transmission tests
⑴ Connection Description: In a certain distance from the test set up two points, through the wireless channel to communicate. Convergence at the pool pump shop, the company set up central dispatch room Yagi directional antenna for testing.
⑵ Test equipment:
① RTU: includes 2 MOSCAD_L, RS-232 communication cable;
② Radio: 2 GM950i, 2 只 2710C, and data lines, power lines;
③ Upper and software: notebook 2, TOOLBOX 8.50 a set, a programming cable;
④ Antenna: Yagi antenna, 2 sets, 2 sets of a certain length of the feeder.
⑶ Connection topology:

Remote data transmission connection point to point topology

⑷ data comparison chart: See the "point to point comparison of data from remote data transfer test table" (see below)
⑸ Notes and Analysis:
① The test consists of testing and point the remote data transmission channel condition two elements. Select from the furthest point of the dispatch center set up an antenna.
② In order to ensure a representative test value, choose the most negative point of convergence for the pool pump to the center's shop dispatch room, during which the distance of about 30 km.
③ tests found the most negative point of the channel quality to satisfy the requirements of the other points in theory, will meet the requirements, the channel test. To facilitate the later test, then the antenna does not have to stand in the pump shop, convenient and can be mounted on other representative areas.
④ Pu shop with the use of two Yagi directional antenna communications, distance about 30 km; the southern suburbs of water between the company and using a suction cup antenna and a Yagi directional antenna communications, distance about 15 km. However, Pu shop with Yagi antenna between the channel quality is good, but the southern suburbs of water with the company than the communication speed between the fast channel quality can be seen a great impact on the communication speed.

Point to point comparison of data from remote polling table test

2 point poll remote simulation test
⑴ connection Description: In a certain distance from the test set up three points, through the wireless channel to communicate. Water filter, respectively, in the southern suburbs, the company set up the dispatch room Yagi antenna, little by little to the point of repeatedly reading the two simulated situations.

⑵ Test Equipment:
① RTU: includes 2 MOSCAD_L, RS-232 communication cable;
② Radio: 2 GM950i, 2 只 2710C, and data lines, power lines;
③ upper and software: notebook 2, TOOLBOX 8.50 a set, a programming cable;
④ Antenna: Yagi antenna, 2 sets, 2 sets of a certain length of the feeder.
⑶ connection topology:

Point to point connection topology polling remote analog

⑷ Data comparison chart: See the "point to point comparison of data from remote analog polling table test" (see below)
⑸ Notes and Analysis:
① As the convergence of the pool pump shop (the most negative point) have been able to ensure the smooth channel, in order to facilitate the use of a representative test set up but easy to point the antenna for the test point. Choose water and company dispatch center of the southern suburbs, during which the distance of about 15 km.
② In the absence of adequate testing of RTU in the desired location, using the dispatch center RTU read every one minute interval of the southern suburbs of water with a RTU, repeatedly. Considered as a poll in a different RTU, so as to achieve the purpose of simulation poll.
③ As the measured radio MOTOROLA found in the first call on when the time spent (T) than after a few time (t) about 1/4t, so the actual time in the poll longer than the test.
Point to point comparison of data from remote analog polling table test

⑴ connection Description: In a certain distance from the test set up three points, through the wireless channel to communicate. Water filter, respectively, in the southern suburbs, southern suburbs of central dispatch room to place water sucker antenna; company set up the dispatch room Yagi antenna.
⑵ test equipment:
① RTU: including three MOSCAD_L, RS-232 communication cable;
② Radio: 3 GM950i, 3 只 2710C, and data lines, power lines;
③ upper and software: notebook 2, TOOLBOX 8.50 a set, a programming cable;

④ Antenna: Yagi Antenna 1 set, 2 sets of suction cup antenna (comes with the feeder), a certain length of the feeder 1 set.
⑶ connection topology:

Polling data connection through a remote relay topology
⑷ data comparison chart: See the "relay remote polling by comparing the test data sheet" (see below)
Remote polling data relay test by comparing Table

⑸ Notes and Analysis:
① planned to set up shop in the South Works Plant Yagi directional antenna, suction cup to place the antenna in the southern suburbs of water as a data store and forward relay station. As the antenna and the reasons are not normally called through the southern suburbs of water, (Plant South Plant control room communications with the company's workshop normal). Abandoned South Works Plant workshop test point, then select the waterworks in the suburbs instead of the point of a remote point.
② companies were selected dispatch room, the southern suburbs of water filter, the southern suburbs of water for the central dispatch room three test points. Dispatch room away from the water company's southern suburbs about 15 kilometers from the southern suburbs of the southern suburbs of water filter water central dispatch room is about 0.1 km.
③ Since only two Yagi antennas, antenna suction cup placed in the southern suburbs of water instead of Yagi antenna, the channel had no significant effect, the normal communication. Water filter water and the southern suburbs of the southern suburbs of central dispatch room; the southern suburbs of water and called the company can normally pass the dispatch room.
4 Remote analog polling immunity tests
⑴ connection Description: In a certain distance from the test set up three points, through the wireless channel to communicate. Water filter, respectively, in the southern suburbs, southern suburbs of central dispatch room to place water sucker antenna; company set up the dispatch room Yagi antenna.
⑵ test equipment:
① RTU: including three MOSCAD_L, RS-232 communication cable;
② Radio: 3 GM950i, 3 只 2710C, and data lines, power lines;
③ upper and software: notebook 2, TOOLBOX 8.50 a set, a programming cable;
④ Antenna: Yagi Antenna 1 set, 2 sets of suction cup antenna (comes with the feeder), a certain length of the feeder 1 set;
⑤ noise sources: an electric drill.
⑶ connection topology:

Remote analog connection topology polling immunity tests

⑷ data comparison table: see "Remote analog interference test data comparing the polling table" (see below)
⑸ Notes and Analysis:
① noise testing in addition to appearing in the interference of man-made drill also included the call with the band outside interference. Radio interference from man-made drill through the feeder is not very close to the basic, but directly interfere with the radio; calls outside interference with the main band is passed through the antenna feeder station.
② Sinosun-band digital radio calls to foreign interference with strong resistance not affected, but the data transfer time will be slightly extended; GM950i band analog radio calls to foreign interference with the weak resistance, greatly slowing down the speed (no interference 3 to 4 times), often failed to send.
③ the use of drill work that interfere with radio, digital radio as cast aluminum casing, drill the interference of strong shielding effect, which received the degree of human disturbance smaller drill can continue to communicate and rate of decline is not very obvious; GM950i analog radio plastic casing, drill for shielding electromagnetic noise signals almost no effect, once drill interference messaging certainly fail. Analog radio for GM950i artificial electromagnetic shielding (metal box into the GM950i analog radio), communication can continue, but the rate is lower.
Polling remote analog interference test data comparison table