JPH04154237A - Polarity control method - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to a method for controlling the polarity of a transmission signal in a bus type network using a bipolar signal as a transmission signal.It also relates to a polarity inverting means and a polarity detection method used in the method. It is about the means.

Conventional Technology Conventional One of the methods for determining transmission rights in a bus network is the competition control method.The competition control method is a transmission path number in which the logical sum of pulses transmitted by two or more terminals becomes the transmission signal on the transmission path. In step 9, each terminal compares the self-transmitted message and the transmission signal on the transmission path bit by bit, and if a terminal that is not transmitting a pulse receives a pulse on the transmission path, it is determined that it has lost the competition with other terminals. When applying the contention control method to a network using AMI signals, which are bipolar signals, it is necessary to cause pulses of the same polarity to collide, and in the transmission section, pulses of positive polarity and pulses of negative polarity must collide. It is set in advance which of the pulses to send out first.9 Therefore, the DC signal is superimposed on the transmission path.
A polarity detecting means for transmitting binary information based on the polarity was considered (conventionally, a polarity detecting means and a polarity control method were thought to detect the polarity from the signal polarity of the received data without superimposing a DC signal). FIG. 8, which was not previously shown, shows the configuration of a conventional means for detecting polarity from the polarity of a DC signal superimposed on a transmission path.

In Figure 8, 8-1 to 8-4 are connected to rectifying diodes.
-5.8-6 is a photocoupler 8-7 to 8-10 are resistors, 8-11a and 8-11b are a pair of transmission media E
8-12a and 8-12b are DC power supplies.The DC power supplies 8-12a and 8-12b are transmission media 8-11a and 8.
- When the voltage is not applied to 11b, the photocoupler 8
-6 is in the off state, and polarity l and polarity 2 are at I (IGH level) by pull-up resistor 8-9. , transmission medium 8-11a, diode 8-1, photocoupler 8-5. diode 8-& transmission medium 8
Current flows in the direction of 11b, and photocoupler 8-5 is O
L photocoupler 8-6 is OFF, and polarity 1 is LO
W, polarity 2 is HIGH level. L 8-
When a DC power source is connected with the polarity of 12b, the transmission medium 8-11h, the diode 8-3. Photo coupler 8
-a, diode 8-4° Current flows in the direction of transmission medium 8-12a, photocoupler 8-5 is OFF, photocoupler 8-6 is ON, and polarity 1 is HIGIL.
Polarity 2 becomes the LOW level, and it is possible to detect the polarity based on the polarity of the DC current.The problem to be solved by the present inventionIn the conventional transmission signal polarity setting method, for some reason during construction, the positive signal line and the negative electrode may be mistakenly connected. If the connection of the signal wires is reversed, the positive polarity signal transmitted from transmitting terminal 1 and the negative polarity signal transmitted from transmitting terminal 2 will be different if the transmitted messages from each terminal connected to the transmission path conflict. Since the signal simultaneously turns on elements such as transistors in each transmitting circuit, the transmitting section of transmitting terminal l and the transmitting section of transmitting terminal 2 are short-circuited, and transmitting terminal l
There was a problem in that an overcurrent could flow between the terminal and the transmitting terminal 2 and destroy each element of the transmitting section.In addition, the means for detecting polarity from the polarity of the direct current requires superimposing the direct current, and the polarity detecting means Means for solving the problem that is disadvantageous in terms of space factor and cost factor, including the circuit components of (1). When the system starts up, the terminal with the master address immediately sends a message, and the terminal with an address other than the master address receives the message sent by the terminal with the master address or the terminal for which polarity control has been completed. Transmission data is not sent until the transmitted message is received, and when a terminal with an address other than the master address receives a message from a terminal with the master address, it transmits data according to the polarity of the received data recognized by the polarity detection means. Even if the signal polarities of the data are matched by a polarity reversing means, in the invention as claimed in claim (2), in order to solve the above problem, the old GK of the polarity signal is set at the polarity set timing before the start bit transmission.
Even if the toggle flip-flop is set or reset in accordance with LOW and the transmission order of the positive signal and the negative signal is reversed, in the invention as claimed in claim (3), in order to solve the above problem, the start bit is detected from the received data. a start bit detection means for detecting a stop bit from received data; an AND element for outputting an AND of the output of the positive polarity comparator and the output of the start bit detection means; An RS flip-flop that is set by the output of the element and reset by the output of the stop bit detection means is added to the receiving section.

According to the invention according to claim (1), IL According to the method described above, it is possible to automatically match the polarity of the transmission signal to the polarity setting of the signal transmitted by the terminal having the master address. According to the invention according to claim (2), even if the device is attached to a terminal with such settings, no overcurrent will flow through the transmission path, and the signal polarity on the transmission path can be kept constant at all times. According to the invention according to claim (3), with the above configuration, it is possible to set whether each terminal sends a signal first from the positive polarity side or the negative polarity side when transmitting a message.
First, it is possible to detect in byte units whether a signal is sent first from the positive polarity side or the negative polarity side on the transmission path when receiving a message. The polarity control method, which is an example, will be explained using Figure 2. Figure 1 is a sequence diagram showing polarity control at system startup. A start message is sent. Terminal method other than the master address After receiving the registration start message, the polarity of the message to be sent matches the signal polarity of the master address, and then the registration request message is returned to the terminal of the master address. Even if the rest of the startup sequence is executed continuously, by adding the processing shown in Figure 1 during the system startup sequence, the signal polarity in the system can be unified to the signal polarity of the master address. The figure is a sequence diagram showing polarity control when only one terminal is powered on.Terminals that are not yet registered in the system (terminals that have messages or master addresses from terminals whose polarity has already been controlled within one system) Do not send any messages yourself until you receive a message sent periodically or irregularly.
~ Figure 2 is an example of transmitting a message from a terminal whose polarity has already been controlled, setting the signal polarity of the transmitted message to match the signal polarity of the received message, and then transmitting the registration request message. After the above-mentioned polarity control is performed, even if the normal start-up sequence is executed continuously,
3rd @ 4th @ This will be explained using FIG. 5. However, FIG.
4 TXDI and TXD2 are AMI
Connected to the analog circuit section for generating signals h T
XDI is the positive pulse generation signal TXD2 is the negative pulse generation signal, and TXDI and TXD2 alternately output positive pulses to transmit the AMI signal to the transmission path. The operation of the polarity reversing means shown in Fig. 3 will be explained using the time chart shown in Fig. 4 @ Fig. 5. Fig. 4 is a time chart when the setting is made to transmit the AMI transmission signal from the negative polarity pulse first. Deam
Listen when no transmission data is output to the transmission signal TXD.
When the polarity set signal PSET becomes active at HIGH while the polarity select signal PSEL is HIGH, unipolar RZ times signal transmission data is outputted to TXD, and the unipolar RZ times signal transmission data is used as the AMI signal transmission data. When converting to negative polarity pulse generation signal TXD2
Figure 5 is a time chart when the AMI side is set to output a positive pulse before the positive pulse generation signal TMDI. Am
While no transmission data is output to the transmission signal TXD
When the polarity set signal PSET becomes HIGH and active while the polarity select signal PSEL is LOW, the unipolar RZ double signal transmission data is output to TXD, and the unipolar RZ double signal transmission data is used as the AMI signal transmission data. When converting to 4-order &!, the positive pulse generation signal TXD1 outputs a positive pulse before the negative pulse generation signal TXD2. An embodiment of the invention in claim (3) will be explained using FIG.
) is a configuration diagram of a transmission signal polarity detection means according to an embodiment of the invention. In FIG. The first comparator 6-2 which outputs the RZ multiplied signal detects the negative polarity pulse of the AMI signal and the second comparator 6-3 which outputs the unipolar RZ multiplied signal is a first OR element; -4 is the start bit detection half, 6-5 is the stop bit detection hand &6
-6 is an AND element, 6-7 is a second OR element, 6-8
is an RS flip-flop.The operation of the polarity detection means shown in Fig. 6 will be explained below using the time chart shown in Fig. 7. However, Fig. 7 shows an example in which signal data is received from the positive polarity side. First, the reset signal RESET is HIGH.
The circuit operation starts when the H level changes to the Lot level. The positive polarity comparator 6-1 detects the positive pulse of the AMI signal and outputs HIGH to the output RXDP. The negative polarity comparator 6-2 The OR element 6-3 detects the negative pulse of the AMI signal and outputs HIGH to the output RXDM.The OR element 6-3 outputs the received data RXD by outputting the logical sum of the RXDP and RXDM. , RXD are all member logic signals. 7th Z Nioite J,t RXDP, RXDM,
3 RXD (duty register 50% by D signal)
at °001011. ．． ．． 1” signal is received from the positive polarity side, the start bit detection means 6
-4 is a stop bit detection means which outputs a positive pulse ST when receiving a start bit and sets the output PD of the RS flip-flop 6-8 to HIGH when the polarity of the AMI signal is positive at the start bit. 6-5 outputs a positive pulse STP when receiving a stop bit and sets the output PD of the RS flip-flop 6-8 to Lot.When receiving from the negative polarity side, RXDP is LOW at the timing when ST is HIGH. Yes, the RS flip-flop 6-8 is not set and the output PD remains Lot.In this way, the RS flip-flop 6-8
The output PD of 8 detects which polarity pulse, positive or negative, the AMI signal is received in units of one code.For example, if the PD is J(IC)I, it means that the reception started from the positive polarity pulse. According to the invention according to claim (1), if the PD is Lot, it is detected that reception has started from the polarity pulse. Since transmission is performed only after the signal polarity of the message sent by itself matches the signal polarity set for the message from the terminal with the master address, there is no need to consider the polarity when installing the signal line. Even if a collision occurs, damage to electronic elements due to short circuit current can be prevented.a According to the invention according to claim (2)? Even if the polarity of the L signal line is different, there is no need to reinstall the signal line, and the polarity of the transmission medium can be changed by changing the polarity setting of the transmission signal.

According to the invention according to claim (3), AM in units of one code
It is possible to easily detect whether the I signal is received first, the positive polarity pulse or the negative polarity pulse.

[Brief explanation of the drawing]

1. Fig. 2 is a sequence diagram showing one embodiment of the invention in claim (1). Fig. 3 is a configuration diagram of a transmission signal polarity inverting means showing one embodiment of the invention in claim (2).
Fourth, Fig. 5 explains the operation of the transmission signal polarity inversion means; Fig. 6 shows the structure of the transmission signal polarity detection means showing an embodiment of the invention in claim 3; 8 is a block diagram of a conventional means for detecting polarity from the polarity of a DC signal superimposed on a transmission path. 3-1...D flip-flop, 3-2 ... Toggle flip-flop, 3-3... 1st 1-input 2-output selector 3-4... 2nd 1-input 2-output selector 6
-1...Positive polarity pulse 6-2...Negative polarity comparator 6
-3...First OR element, 6-4...Start bit detection means, 6-5...Stop bit detection ratio 6
-6...AND element, 6-7...Second OR element, 6-8...RS flip-flop, 8-1.8-2
．． 8-3.8-4... Rectifier diode, 8-5.8
-6... Photocoupler 8-7.8-8.8-9.
810...Resistance 8-11a, 8-11b...Pair of transmission media 2a, 8-12b --- Name of DC electric agent Patent attorney Akira Kokaji and two others Diagram System startup fro 1. Conflict Control Fa-a Anonymous Telegram One Te (2-ru Saliva Figure Standing I ta * Keno) Guwa On” 1 Conflict Control Master Address Residence ￥m Clear η Conflict Confidence A fati go map

Claims (3)

[Claims] (1) In a system in which multiple terminals communicate using multipolar signals over a single transmission medium, polarity detection means for detecting the polarity of the transmission signal and polarity inversion means that can select the polarity of the transmission signal One of the terminals connected to the transmission medium is set as the master address, and when the system starts up, the terminal with the master address immediately sends a message, and the terminal with an address other than the master address uses the master address. A terminal with a master address or a terminal with an address other than the master address will not send a message until it receives a message from a terminal for which polarity control has already been completed, and a terminal with an address other than the master address will not transmit a message from a terminal with a master address or another terminal whose polarity control has already been completed. When a message is received, the polarity reversing means matches the signal polarity of the transmitted data with the polarity of the received data recognized by the polarity detection means. A transmission signal polarity control method that keeps the signal polarity of the transmitted message constant. (2) The unipolar RZ signal output in synchronization with the transmission clock is input to the first 1-input 2-output selector, and the unipolar RZ signal is output in synchronization with the transmission clock.
The output of the toggle flip-flop that inverts the output in synchronization with the transmission clock when the Z signal is positive polarity is used as the select signal of the first 1-input 2-output selector, and the unipolar R
In a unipolar RZ signal to bipolar AMI signal conversion circuit that alternately outputs positive polarity pulses of the Z signal to the output of the first 1-input 2-output selector, a polarity set signal is input, and a polarity select signal is used as a select signal. adding a second 1-input 2-output selector, and connecting one output of the second 1-input 2-output selector to the set input of the toggle flip-flop and the other output to the reset input of the toggle flip-flop; The polarity reversing means according to claim 1, wherein the polarity of the bipolar AMI signal can be easily selected. (3) A first comparator that demodulates the positive polarity pulse of the asynchronous telegram transmitted as a bipolar signal on the line and outputs a unipolar RZ signal, and a first comparator that demodulates the negative polarity pulse of the bipolar signal. a second comparator that outputs a unipolar RZ signal; an OR element that outputs the logical sum of the outputs of the first and second comparators; and an asynchronous reception method from the output of the OR element. a start bit detection means for detecting a start bit of data and outputting a set timing pulse; a stop bit detection means for detecting a stop bit of received data from the output of the OR element and outputting a reset pulse; an AND element that outputs the logical product of the output of the comparator and the output of the start bit detection means; and the output of the AND element is input to a set terminal, and the output of the stop bit detection means is received as an input to a reset terminal. 2. The polarity detecting means according to claim 1, further comprising an RS flip-flop which changes its output depending on whether the polarity of the bipolar signal at the start bit of the data is positive or negative and holds the output for a period up to the stop bit.