JPH0544211B2 - - Google Patents
Info
- Publication number
- JPH0544211B2 JPH0544211B2 JP58061411A JP6141183A JPH0544211B2 JP H0544211 B2 JPH0544211 B2 JP H0544211B2 JP 58061411 A JP58061411 A JP 58061411A JP 6141183 A JP6141183 A JP 6141183A JP H0544211 B2 JPH0544211 B2 JP H0544211B2
- Authority
- JP
- Japan
- Prior art keywords
- equalization
- transmission line
- station
- waveform
- gain
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
- 230000005540 biological transmission Effects 0.000 claims description 65
- 230000006735 deficit Effects 0.000 claims description 3
- 238000010586 diagram Methods 0.000 description 9
- 230000007812 deficiency Effects 0.000 description 6
- 230000006866 deterioration Effects 0.000 description 2
- 230000002238 attenuated effect Effects 0.000 description 1
- 239000003990 capacitor Substances 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 230000000630 rising effect Effects 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L12/00—Data switching networks
- H04L12/28—Data switching networks characterised by path configuration, e.g. LAN [Local Area Networks] or WAN [Wide Area Networks]
- H04L12/40—Bus networks
Landscapes
- Engineering & Computer Science (AREA)
- Computer Networks & Wireless Communication (AREA)
- Signal Processing (AREA)
- Arrangements For Transmission Of Measured Signals (AREA)
- Amplifiers (AREA)
- Dc Digital Transmission (AREA)
- Small-Scale Networks (AREA)
- Cable Transmission Systems, Equalization Of Radio And Reduction Of Echo (AREA)
Description
【発明の詳細な説明】
本発明はデータウエイのバスレシーバに関し、
更に詳しくは、その内部に等化機能をもたせて通
信ラインの長距離化を図ることができるうにした
バスレシーバに関する。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a data way bus receiver;
More specifically, the present invention relates to a bus receiver that has an internal equalization function and can extend communication lines over long distances.
伝送線路(同軸ケーブルが多い)1本を複数の
機器で共有する所謂データウエイは広く普及して
おり、第1図にその構成例を示す。図はリニア形
のデータウエイを示している。図において、S1〜
So(n整数、以下同じ)はステーシヨン、T1〜To
はトランシーバ、A1〜Aoはバス結合器、DBは伝
送線路である。各ステーシヨンS1〜Soと伝送線路
DBとの接続はバス結合器A1〜Aoによつて行わ
れ、トランシーバT1〜Toによつて論理レベルに
変換される。 A so-called data way, in which a single transmission line (often a coaxial cable) is shared by multiple devices, is widely used, and an example of its configuration is shown in FIG. The figure shows a linear dataway. In the figure, S 1 ~
S o (n integer, same below) is station, T 1 ~ T o
is a transceiver, A 1 to A o are bus couplers, and DB is a transmission line. Each station S 1 ~ S o and transmission line
The connection to DB is made by bus combiners A 1 -A o and converted to logic levels by transceivers T 1 -T o .
このような構成のデータウエイでは、伝送線路
が長くなると、帯域制限が増す。1次遅れ特性の
ゲインになつた伝送線路では、1/(1+jωT)
なるゲイン(T:時定数、ω:角周波数、j:虚
数単位)の時定数Tが大きくなつて帯域制限が増
す。 In a dataway with such a configuration, the longer the transmission line becomes, the more the band limit becomes. In a transmission line whose gain has a first-order lag characteristic, 1/(1+jωT)
As the time constant T of the gain (T: time constant, ω: angular frequency, j: imaginary unit) increases, the band limitation increases.
第2図は信号の伝播特性を示す図である。図に
おいて、aはステーシヨンS1の、bはステーシヨ
ンS2の、cはステーシヨンSoのそれぞれ受信信号
波形を示している。ステーシヨンSoにおいては、
受信信号が減衰しかつ波形がなまつていることが
わかる。また、ケーブル長が増すと減衰と帯域制
限が増加する。1対1の伝送であれば、減衰や帯
域制限はこれと逆極性をもつ回路により等化が可
能である。 FIG. 2 is a diagram showing signal propagation characteristics. In the figure, a shows the received signal waveform of station S1 , b shows the received signal waveform of station S2 , and c shows the received signal waveform of station S0 . At station S o ,
It can be seen that the received signal is attenuated and the waveform is blunted. Additionally, increasing cable length increases attenuation and bandwidth limitations. In the case of one-to-one transmission, attenuation and band limitation can be equalized by a circuit with the opposite polarity.
しかしながら、データウエイはN:Nの通信
(N任意の整数)を行うものである。従つて、デ
ータウエイ上にあるステーシヨンと、このステー
シヨンと通信を行う相手方のステーシヨンとの間
の伝送線路長は特定されていない。このため、デ
ータウエイの設置時に、等化回路に設けられた可
変素子の回路定数を変えて伝送線路のゲイン調整
を行うことは、通信を行う伝送線路の長さが特定
されていないため、非常に難しかつた。特に、伝
送線路が長い場合は、伝送線路の最大長を使つて
通信を行つたり、伝送線路のごく一部を使つて通
信を行つたりすることがあり、伝送線路長の変化
が大きくなる。このため、伝送線路のゲイン調整
は非常に難しくなる。 However, the data way performs N:N communication (N is any integer). Therefore, the length of the transmission line between the station on the dataway and the other station with which this station communicates is not specified. Therefore, when installing the dataway, it is extremely difficult to adjust the gain of the transmission line by changing the circuit constants of the variable elements installed in the equalization circuit, as the length of the transmission line for communication is not specified. It was difficult. In particular, when the transmission line is long, communication may be performed using the maximum length of the transmission line or a small portion of the transmission line, resulting in large changes in the transmission line length. . This makes it extremely difficult to adjust the gain of the transmission line.
このような理由から、1対1伝送の場合に比べ
第1図のリニア形データウエイの場合、伝送線路
長が大幅に制限されていた。 For these reasons, in the case of the linear dataway shown in FIG. 1, the length of the transmission line is significantly limited compared to the case of one-to-one transmission.
本発明はこのような点に鑑みてなされたもので
あり、1次遅れ特性のゲインになつた伝送線路を
用いたデータウエイで、受信用アンプで等化を行
うことにより、伝送線路の時定数を小さくして帯
域を広げ、伝送線路の長距離化を実現した等化機
能付バスレシーバを提供することを目的とする。 The present invention has been made in view of these points, and it is a data way using a transmission line that has a gain with a first-order lag characteristic, and by performing equalization in a receiving amplifier, the time constant of the transmission line can be changed. The purpose of the present invention is to provide a bus receiver with an equalization function that has a smaller value, a wider band, and a longer transmission line.
本発明は、
伝送線路の長さに応じてゲインがGo=Kl/
(1+jωTl)(ただし、Kl:定数、Tl:時定数、
ω:角周波数、j:虚数単位)で表され、時定数
Tlは線路長に比例して大きくなる伝送線路を複
数個のステーシヨンで共有するデータウエイの各
ステーシヨン入口部に設けられたバスレシーバに
おいて、
前記伝送線路の伝送波形に生じた減衰を補償す
る等化特性を有し、伝送波形の等化量は、
(伝送線路の一端に位置する基準となるステーシ
ヨンの隣のステーシヨンにおける伝送波形の等化
オーバー量)
=(伝送線路の他端に位置するステーシヨンにお
ける等化不足量)
になつていて、ゲインが
G=K0・(1+iωTl)/{1+(jωTl/2)}
K0:定数
になつた受信用アンプ、
を具備したことを特徴とする等化機能付バスレシ
ーバである。 In the present invention, the gain is determined according to the length of the transmission line as G o = Kl/
(1+jωTl) (Kl: constant, Tl: time constant,
ω: angular frequency, j: imaginary unit), time constant
Tl is equalization that compensates for the attenuation that occurs in the transmission waveform of the transmission line in the bus receiver installed at the entrance of each station of a dataway where multiple stations share the transmission line, which increases in proportion to the line length. The amount of equalization of the transmitted waveform is (the amount of over-equalization of the transmitted waveform at the station next to the reference station located at one end of the transmission line) = (the amount of over-equalization of the transmitted waveform at the station located at the other end of the transmission line) equalization deficit), and the gain is G=K 0・(1+iωTl)/{1+(jωTl/2)} K 0 : a constant. It is a functional bus receiver.
以下、図面を用いて本発明を詳細に説明する。 Hereinafter, the present invention will be explained in detail using the drawings.
第3図は、トランシーバの構成を示す図であ
る。図において、1は伝送線路DBに設けられた
結合器、2は送信用ドライバ、3は受信用アン
プ、4は該アンプの出力を受ける識別器である。
アンプ3と識別器4とでバスレシーバを構成し、
アンプ3に等化機能を設けている。 FIG. 3 is a diagram showing the configuration of the transceiver. In the figure, 1 is a coupler provided on the transmission line DB, 2 is a transmitting driver, 3 is a receiving amplifier, and 4 is a discriminator that receives the output of the amplifier.
The amplifier 3 and the discriminator 4 constitute a bus receiver,
Amplifier 3 is provided with an equalization function.
第4図は伝送線路のゲイン特性を示す図であ
る。横軸は周波数、縦軸はゲインである。fS1は
ステーシヨンS2(第1図参照)までの、fS2はステ
ーシヨンSoまでの伝送線路のゲイン特性を示し、
それぞれにおいて1は等化なしの場合を、2は等
化適性の場合を、3は等化不適の場合をそれぞれ
示している。第4図で、(1)が3の右にあるのは、
グラフfS1の1の場合における下降線とグラフfS2
の3の場合における下降線とが重なつているため
である。グラフfS1の2の場合と3の場合がはね
上がつているのは、ステーシヨンS2では2の場合
と3の場合に等化オーバーが生じるためである。 FIG. 4 is a diagram showing the gain characteristics of the transmission line. The horizontal axis is frequency and the vertical axis is gain. f S1 is the gain characteristic of the transmission line up to station S 2 (see Figure 1), f S2 is the gain characteristic of the transmission line up to station S o ,
In each case, 1 indicates a case without equalization, 2 indicates a case where equalization is suitable, and 3 indicates a case where equalization is inappropriate. In Figure 4, (1) is to the right of 3 because
The descending line in case 1 of graph f S1 and graph f S2
This is because the descending line in case 3 overlaps. The reason why cases 2 and 3 in the graph f S1 jump is because over-equalization occurs in cases 2 and 3 at station S 2 .
第5図は伝送波形を示す図であり、aはステー
シヨンSoの、bはステーシヨンS2の伝送波形を示
している。図中の番号1〜3は第4図のそれと同
じである。1は等化がない場合であり、近くのス
テーシヨンでは適であるが、遠くのステーシヨン
では不適となる。3はステーシヨンSoで完全な波
形が得られるように等化を行つた場合であるが、
このようにするとステーシヨンS2で等化が大きく
なりすぎる。これに対し、2ではステーシヨンSo
では等化不足であるが、その代わりステーシヨン
S2でもそれほど波形の劣化が生じていない。この
ことから、ステーシヨンSoにおける等化不足量と
ステーシヨンS2における等化オーバー量が等しく
なるように等化量を設定した等化機能を第3図の
受信用アンプ3に持たせれば、信号の減衰が抑制
されたデータウエイを実現することができること
になる。第5図で、a図の波形レベルがb図の波
形レベルに比して低いのは、ステーシヨンSoに至
るまでの伝送線路長がステーシヨンS2に至るまで
の伝送線路長よりも長いため、ステーシヨンSoの
受信波形の減衰が大きいからである。 FIG. 5 is a diagram showing transmission waveforms, where a shows the transmission waveform of station S o and b shows the transmission waveform of station S 2 . Numbers 1 to 3 in the figure are the same as those in FIG. 1 is the case where there is no equalization, which is appropriate for nearby stations, but inappropriate for distant stations. 3 is the case where equalization is performed to obtain a complete waveform at station S o ,
This would result in too much equalization at station S2 . On the other hand, in 2, the station S o
In this case, the equalization is insufficient, but the station
Even with S 2 , there is not much waveform deterioration. From this, if the receiving amplifier 3 in Fig. 3 is provided with an equalization function that sets the equalization amount so that the equalization under-equalization amount at station S o is equal to the equalization over-equalization amount at station S 2 , the signal This means that it is possible to realize a dataway in which attenuation of is suppressed. In Figure 5, the reason why the waveform level in Figure a is lower than the waveform level in Figure b is because the length of the transmission line up to station S o is longer than the length of the transmission line up to station S2 . This is because the attenuation of the received waveform at station S o is large.
第6図は、等化機能をもつた受信用アンプの一
構成例を示す電気回路図である。図に示すアンプ
はトランジスタQ1,Q2を用いた差動増幅器によ
り構成されており、トランジスタQ1,Q2のエミ
ツタ間に接続されたRC直列回路10が等化回路
をなしてる。コレクタ抵抗をRL、エミツタ抵抗
をRE、コンデンサCの静電容量もCで表すとす
れば、こアンプのゲインGは次式で与えられる。 FIG. 6 is an electric circuit diagram showing a configuration example of a receiving amplifier having an equalization function. The amplifier shown in the figure is constituted by a differential amplifier using transistors Q 1 and Q 2 , and an RC series circuit 10 connected between the emitters of transistors Q 1 and Q 2 forms an equalization circuit. Assuming that the collector resistance is R L , the emitter resistance is R E , and the capacitance of the capacitor C is also C, the gain G of this amplifier is given by the following equation.
G=RL/2RE×1+jωC(R+2RE)/1+jωCR
=K01+jωT1/1+jωT2 (1)
K0=RL/2R5 (2)
T1=C(R+2RE) (3)
T2CR (4)
今、ステーシヨンS1からSoへのゲインをGo、
ステーシヨンS1からS2へのゲインをG2とすると、
これらはそれぞれ次式で与えられる。G=R L /2R E ×1+jωC (R+2R E )/1+jωCR =K 0 1+jωT 1 /1+jωT 2 (1) K 0 =R L /2R 5 (2) T 1 =C(R+2R E ) (3) T 2 CR (4) Now, the gain from station S 1 to S o is G o ,
If the gain from station S 1 to S 2 is G 2 , then
These are each given by the following equations.
Go=Kl/(1+jωTl) (5)
Kl:定数、Tl:時定数
G2=1 (6)
ここで、時定数Tlは線路長に応じて決まるも
のである。 G o =Kl/(1+jωTl) (5) Kl: constant, Tl: time constant G 2 =1 (6) Here, the time constant Tl is determined according to the line length.
Go、G2式(1)のゲインGで等化すると、次のと
おりになる。 G o , G 2 When equalized by the gain G in equation (1), the following is obtained.
Go′=Go・G
=KlK01/1+jωTl×1+jωT1/1+jωT2 (7)
G2′=G2・G
=K01+jωT1/1+jωT2 (8)
ここで、Tl=T1となるように選ぶと、Go′と
G2′は次のとおりになる。 G o ′=G o・G = KlK 0 1/1+jωTl×1+jωT 1 /1+jωT 2 (7) G 2 ′=G 2・G =K 0 1+jωT 1 /1+jωT 2 (8) Here, Tl=T 1 and If you choose so that G o ′ and
G 2 ′ is as follows.
Go′=KlK01/1+jωT2 (9)
G2′=K01+jωTl/1+jωT2 (10)
第7図はステーシヨンS2とSoの受信波形を示し
た図であり、aは無等化時の受信波形を、bは等
化後の受信波形を示した図である。何れも1はス
テーシヨンS2の2はステーシヨンSoのそれぞれ受
信波形を示している。G o ′=KlK 0 1/1+jωT 2 (9) G 2 ′=K 0 1+jωTl/1+jωT 2 (10) Figure 7 shows the received waveforms of stations S 2 and S o , where a is unequal. FIG. 3B shows a received waveform during equalization, and b shows a received waveform after equalization. In each case, 1 indicates the received waveform of the station S2 , and 2 indicates the received waveform of the station S0 .
ここで、送信波形はルス信号であり、第7図の
bに示すステーシヨンS2とSoの受信波形(波形1
と波形2)は、式(9)と(10)に示す伝達関数ステツプ
応答波形になる。従つて、第7図のbに示す波形
1と波形2の関数y2(t)とyo(t)は次式で与えられ
る。 Here, the transmitted waveform is a Luz signal, and the received waveform (waveform 1
and waveform 2) become transfer function step response waveforms shown in equations (9) and (10). Therefore, the functions y 2 (t) and y o (t) of waveform 1 and waveform 2 shown in FIG. 7b are given by the following equations.
y2(t)=K0
+K0{(Tl/T2)−1}×exp(−t/T2) (11)
yo(t)
=KlK0{1−exp(−t/T2)} (12)
ここで、tは時間で、受信波形の立ち上がり時
点をt=0とする。y 2 (t)=K 0 +K 0 {(Tl/T 2 )-1}×exp(-t/T 2 ) (11) y o (t) =KlK 0 {1-exp(-t/T 2 )} (12) Here, t is time, and the rising point of the received waveform is t=0.
式(11)と(12)からステーシヨンS2とSoにおける波形
の偏差Δ2とΔoは次のとおりになる。 From equations (11) and (12), the waveform deviations Δ 2 and Δ o at stations S 2 and S o are as follows.
Δ2=y2(tPW)−y2(∞)
=K0{(Tl/T2)−1}
×exp(−tPW/T2) (13)
Δo=yo(tPW)−yo(∞)
=KlK0exp(−tPW/T2) (14)
tPW:パルス幅
ここで、Δ2/K0とΔo/KlK0を等しくすること
を考える。両者が等しい条件は、式(13)と(14)から
Tl=2T2となる。Δ2をK0で割つたものと、Δoを
KlK0で割つたものとを比較しているのは、ステ
ーシヨンS2とSoとでは受信波形の減衰の度合いが
異なるためである。Δ 2 =y 2 (t PW )−y 2 (∞) =K 0 {(Tl/T 2 )−1} ×exp(−t PW /T 2 ) (13) Δ o =y o (t PW ) −y o (∞) = KlK 0 exp (−t PW /T 2 ) (14) t PW : Pulse width Here, consider making Δ 2 /K 0 and Δ o /KlK 0 equal. The condition that both are equal is given by equations (13) and (14).
Tl= 2T2 . Δ 2 divided by K 0 and Δ o
The reason why the value divided by KlK 0 is compared is that the degree of attenuation of the received waveform is different between stations S 2 and S o .
Tl=2T2より、式(9)は次のとおりになる。 From Tl=2T 2 , equation (9) becomes as follows.
Go′=KlK01/1+(jωTl/2) (15)
第7図bの上側の破線はステーシヨンS2の受信
波形がくずれのない完全なパルス波形である場合
の波形レベルである。また、第7図bの下側の破
線はステーシヨンSoの受信波形がくずれのない完
全なパルス波形である場合の波形レベルである。G o ′=KlK 0 1/1+(jωTl/2) (15) The upper broken line in FIG. 7b is the waveform level when the received waveform of the station S 2 is a complete pulse waveform without distortion. Furthermore, the lower broken line in FIG. 7b is the waveform level when the received waveform of the station So is a complete pulse waveform without distortion.
このことから、波形偏差Δ2は上側の破線と波
形1との間でとり、波形偏差Δoは下側の破線と
波形2との間でとつている。 From this, the waveform deviation Δ 2 is taken between the upper broken line and waveform 1, and the waveform deviation Δ o is taken between the lower broken line and waveform 2.
これによつて、式(5)に示されるゲインGoが式
(15)で示されるゲインGo′に等化され、1次遅れ特
性の時定数がTlからTl/2になる。 As a result, the gain G o shown in equation (5) becomes
It is equalized to the gain G o ' shown in (15), and the time constant of the first-order lag characteristic changes from Tl to Tl/2.
ここで、等化前のゲインである式(5)で示される
ゲインでは、ωTl=1すなわちω=1/Tl近く
まではゲインが一定である。 Here, the gain shown by equation (5), which is the gain before equalization, is constant until ωTl=1, that is, close to ω=1/Tl.
一方、等化後のゲインである式(15)で示されるゲ
インでは、ωTl/2=1すなわちω=2/Tl近
くまではゲインが一定になる。 On the other hand, in the gain expressed by equation (15), which is the gain after equalization, the gain is constant until ωTl/2=1, that is, close to ω=2/Tl.
このことから、等化後のゲインは等化前のゲイ
ンに比べてゲイン一定になる周波数帯域が2倍に
なる。これによつて、伝送線路の帯域が広がり、
伝送線路の長距離化が可能になる。 From this, the frequency band in which the gain is constant is twice as large as the gain after equalization compared to the gain before equalization. This expands the bandwidth of the transmission line,
It becomes possible to extend the length of transmission lines.
ここで、各ステーシヨンにおける等化特性につ
いて説明する。 Here, the equalization characteristics at each station will be explained.
Go=Kl/(1+jωTl),G2=1なるゲインを
もつた伝送線路を、本発明にかかるバスレシーバ
を使つて等化すると、
(伝送線路の一端に位置する基準となるステーシ
ヨンの隣のステーシヨンにおける伝送波形の等化
オーバー量)
=(伝送線路の他端に位置するステーシヨンにお
ける等化不足量)
になる。これによつて、伝送線路の一端に位置す
るステーシヨンの隣のステーシヨンでは等化オー
バー量が最大で、伝送線路が長くなるにつれて等
化オーバー量が減少していき、やがて0になり、
さらに等化不足へと転じる。そして、伝送線路の
他端に位置するステーシヨンにおける等化不足量
は、伝送線路の一端に位置するステーシヨンの隣
のステーシヨンにおける等化オーバー量と等しく
なる。 When a transmission line with a gain of G o = Kl/(1 + jωTl), G 2 = 1 is equalized using the bass receiver according to the present invention, (the station next to the reference station located at one end of the transmission line) The amount of over-equalization of the transmission waveform at the station) = (the amount of under-equalization at the station located at the other end of the transmission line). As a result, the over-equalization amount is maximum at the station next to the station located at one end of the transmission line, and as the transmission line becomes longer, the over-equalization amount decreases until it reaches 0.
Furthermore, it turns into insufficient equalization. Then, the equalization deficit amount at the station located at the other end of the transmission line is equal to the equalization over amount at the station adjacent to the station located at one end of the transmission line.
このことから、第1図のステーシヨンS1を基準
とした場合、各ステーシヨンにおける等化の過不
足量は第8図の実線グラフg2に示すとおりにな
る。すなわち、等化の過不足量は±aの範囲内に
なる。 From this, when station S1 in FIG. 1 is used as a reference, the amount of excess or deficiency in equalization at each station is as shown in the solid line graph g2 in FIG. 8. That is, the amount of excess or deficiency in equalization falls within the range of ±a.
これに対して、等化なしの場合(第5図の1の
場合)は、各ステーシヨンにおける等化の過不足
量は第8図の2点鎖線グラフg1に示すとおりにな
る。また、ステーシヨンSoで完全な波形が得られ
るように等化を行つた場合(第5図の3の場合)
は、各ステーシヨンにおける等化量の過不足量は
第8図の一点鎖線グラフg3に示すとおりになる。
等化の過不足量はグラフg1では最大−2a、グラフ
g3では最大2aになる。 On the other hand, in the case of no equalization (case 1 in FIG. 5), the amount of excess or deficiency in equalization at each station is as shown by the two-dot chain line graph g1 in FIG. Also, when equalization is performed to obtain a complete waveform at station S o (case 3 in Figure 5)
The excess or deficiency of the equalization amount at each station is as shown in the dashed-dotted line graph g3 in FIG.
The amount of excess or deficiency in equalization is at most −2a for graph g 1 , and the graph
In g 3 it becomes maximum 2a.
このように本発明では等化の過不足量の大きさ
(絶対値)が1の場合と3の場合に比べて1/2に抑
えられる。これによつて、波形の劣化が少なくな
り、伝送線路長を延ばすことができる。 In this way, in the present invention, the magnitude (absolute value) of the amount of excess or deficiency in equalization is suppressed to 1/2 compared to the case of 1 and the case of 3. This reduces waveform deterioration and allows the transmission line length to be extended.
第6図の回路における回路定数の値は次のよう
にして決められる。 The values of circuit constants in the circuit of FIG. 6 are determined as follows.
式(3)と(4)、及び、Tl=T1,Tl=2T2なる条件
から、
C(R+2RE)=Tl (16)
CR=Tl/2 (17)
式(16)と(17)から次式が得られる。 From equations (3) and (4) and the conditions Tl=T 1 and Tl=2T 2 , C(R+2R E )=Tl (16) CR=Tl/2 (17) Equations (16) and (17) The following equation is obtained from
R=2RE (18)
ここで、ゲインがGo=Kl/(1+jωTl)にな
つた伝送線路の時定数Tlは、伝送線路長に比例
して大きくなる。従つて、データウエイの伝送線
路長を決めると時定数Tlの値も自ずと定められ
る。 R=2R E (18) Here, the time constant Tl of the transmission line whose gain is G o =Kl/(1+jωTl) increases in proportion to the length of the transmission line. Therefore, when the transmission line length of the data way is determined, the value of the time constant Tl is also determined automatically.
このことから、式(16)〜(18)で、Tlは既知の値、
R,C及びREは未知数になる。従つて、式(16)〜
(18)を連立方程式としてR,C,REの値が求めら
れる。すなわち、伝送線路長が決まると、R,
C,REの値が定まる。 From this, in equations (16) to (18), Tl is a known value,
R, C and R E become unknown quantities. Therefore, formula (16) ~
The values of R, C, and R E can be found using (18) as a simultaneous equation. That is, once the transmission line length is determined, R,
The values of C and R E are determined.
また、式(2)のK0も伝送線路長に応じて決まる
値であるため、式(2)のRLは、K0の値と、前述し
た演算により求めたREの値から算出される。 In addition, since K 0 in equation (2) is also a value determined depending on the transmission line length, R L in equation (2) is calculated from the value of K 0 and the value of R E obtained by the above calculation. Ru.
これにより、データウエイの長さが決まると、
受信用アンプのゲインが定まる。すなわち、本発
明では、伝送線路長が決まると、伝送線路のゲイ
ンが決まつてしまう。従つて、データウエイの設
置時における伝送線路のゲイン調整は、本発明で
不要になる。 This determines the length of the dataway,
The gain of the receiving amplifier is determined. That is, in the present invention, when the transmission line length is determined, the gain of the transmission line is determined. Therefore, the present invention eliminates the need to adjust the gain of the transmission line when installing the dataway.
以上説明したように本発明によれば、1次遅れ
特性のゲインになつた伝送線路を用いたデータウ
エイで、受信用アンプで等化を行うことにより、
伝送線路の時定数を小さくして帯域を広げ、伝送
線路の長距離化を実現できる。 As explained above, according to the present invention, by performing equalization in a receiving amplifier on a data way using a transmission line with a gain having a first-order lag characteristic,
By reducing the time constant of the transmission line and widening the band, it is possible to make the transmission line longer.
第1図はデータウエイの構成を示す図、第2図
は信号の伝播特性を示す図、第3図トランシーバ
の構成を示す図、第4図は伝送線路のゲイン特性
を示す図、第5図は伝送波形を示す図、第6図は
受信用アンプの具体的構成例を示す電気回路図、
第7図は波形偏差を示す図、第8図は各ステーシ
ヨンにおける等化特性を示した図である。
S1〜So…ステーシヨン、T1〜To…トランシー
バ、A1〜Ao…結合器、DB…伝送線路、1…結合
器、2…ドライバ、3…受信用アンプ、4…識別
器、10…等化回路。
Figure 1 shows the configuration of the dataway, Figure 2 shows the signal propagation characteristics, Figure 3 shows the configuration of the transceiver, Figure 4 shows the gain characteristics of the transmission line, and Figure 5. 6 is a diagram showing a transmission waveform, and FIG. 6 is an electric circuit diagram showing a specific configuration example of a receiving amplifier.
FIG. 7 is a diagram showing waveform deviation, and FIG. 8 is a diagram showing equalization characteristics at each station. S 1 - S o ...Station, T 1 - T o ... Transceiver, A 1 - A o ... Coupler, DB... Transmission line, 1... Coupler, 2... Driver, 3... Receiving amplifier, 4... Discriminator, 10... Equalization circuit.
Claims (1)
(1+jωTl)(ただし、Kl:定数、Tl:時定数、
ω:角周波数、j:虚数単位)で表され、時定数
Tlは線路長に比例して大きくなる伝送線路を複
数個のステーシヨンで共有するデータウエイの各
ステーシヨン入口部に設けられたバスレシーバに
おいて、 前記伝送線路の伝送波形に生じた減衰を補償す
る等化特性を有し、伝送波形の等化量は、 (伝送線路の一端に位置する基準となるステーシ
ヨンの隣のステーシヨンにおける伝送波形の等化
オーバー量) =(伝送線路の他端に位置するステーシヨンにお
ける等化不足量) になつていて、ゲインが G=K0・(1+iωTl)/{1+(jωTl/2)} K0:定数 になつた受信用アンプ、 を具備したことを特徴とする等化機能付バスレシ
ーバ。[Claims] 1. The gain is G o = Kl/ depending on the length of the transmission line.
(1+jωTl) (Kl: constant, Tl: time constant,
ω: angular frequency, j: imaginary unit), time constant
Tl is equalization that compensates for the attenuation that occurs in the transmission waveform of the transmission line in the bus receiver installed at the entrance of each station of a dataway where multiple stations share the transmission line, which increases in proportion to the line length. The amount of equalization of the transmitted waveform is (the amount of over-equalization of the transmitted waveform at the station next to the reference station located at one end of the transmission line) = (the amount of over-equalization of the transmitted waveform at the station located at the other end of the transmission line) equalization deficit), and the gain is G=K 0・(1+iωTl)/{1+(jωTl/2)} K 0 : a constant. Functional bass receiver.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP6141183A JPS59186445A (en) | 1983-04-07 | 1983-04-07 | Bus receiver with equalizing function |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP6141183A JPS59186445A (en) | 1983-04-07 | 1983-04-07 | Bus receiver with equalizing function |
Publications (2)
Publication Number | Publication Date |
---|---|
JPS59186445A JPS59186445A (en) | 1984-10-23 |
JPH0544211B2 true JPH0544211B2 (en) | 1993-07-05 |
Family
ID=13170349
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP6141183A Granted JPS59186445A (en) | 1983-04-07 | 1983-04-07 | Bus receiver with equalizing function |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPS59186445A (en) |
Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS5223241A (en) * | 1975-08-15 | 1977-02-22 | Fujitsu Ltd | Frequency compensation system |
JPS52116156A (en) * | 1976-03-26 | 1977-09-29 | Iwatsu Electric Co Ltd | Wide-band amplifier circuit |
JPS5379306A (en) * | 1976-12-24 | 1978-07-13 | Hitachi Ltd | Dp sugnal transmission system |
JPS54115010A (en) * | 1978-02-28 | 1979-09-07 | Fujitsu Ltd | Communication system |
-
1983
- 1983-04-07 JP JP6141183A patent/JPS59186445A/en active Granted
Patent Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS5223241A (en) * | 1975-08-15 | 1977-02-22 | Fujitsu Ltd | Frequency compensation system |
JPS52116156A (en) * | 1976-03-26 | 1977-09-29 | Iwatsu Electric Co Ltd | Wide-band amplifier circuit |
JPS5379306A (en) * | 1976-12-24 | 1978-07-13 | Hitachi Ltd | Dp sugnal transmission system |
JPS54115010A (en) * | 1978-02-28 | 1979-09-07 | Fujitsu Ltd | Communication system |
Also Published As
Publication number | Publication date |
---|---|
JPS59186445A (en) | 1984-10-23 |
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