JPH04208738A - Signal transmission method - Google Patents

Abstract

PURPOSE:To improve the transmission efficiency by dividing the data signal part of a format to assign divided parts to plural specific devices and simultaneously transmitting data to plural specific devices and extracting data of the divided part assigned to each specific device from a received transmission signal. CONSTITUTION:A data signal part 1 of the signal format is divided, and divided parts (4 bits) are assigned to respective control object devices A and B. A center unit 3 transfers the transmission signal (4-bit data to the control object device A, 4-bit data to the control object device B, and one parity bit) to control object devices A and B through a signal line 5. When confirming transfer order '1' assigned to control object devices A and B, control object devices A and B take in the signal on the signal line 5 into themselves. Each of control object device A and B extracts four bits of the signal assigned to itself in the transmission signal from the received signal.

Description

[Detailed description of the invention]

[00011

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a signal transmission method for transmitting signals between electronic devices using a multiplex transmission method, and particularly to a signal transmission method suitable for a programmable controller. [0002] Conventionally, FIG. 4 shows the format of a transmission signal when transmitting a signal from a programmable controller to a controlled device using a multiplex transmission method. [00031 In FIG. 4, a signal sent to one of the devices to be controlled consists of a data section 1 and a parity section 2, and the data section 1 usually consists of 8 bits of data. When transmitting signals to multiple devices to be controlled, specify the destination devices in the order of signal transmission. In some cases, an address section is provided in the above-mentioned signal, and the device to which the signal is transmitted is specified by the address specification. The device on the signal receiving side counts the transmission order of the signals and takes into the device only the signals in the order assigned to it. [0004]

However, in the conventional signal transmission method of this type, when the number of bit signals to be transmitted to one controlled device is less than 8', for example 6', the signal format described above cannot be used. By adding two apparent transmission signals to the above °“6'' signals, it becomes as if “
Assuming that there are 8'' transmission signals, signal transmission is performed at fixed timings. On the other hand, the controlled device extracts only the necessary 6° transmission signals from the received signals. For this reason, there is a problem in that the more control devices have a number of signal points smaller than the maximum number of bits that can be transmitted, the more unused (apparent) signals there are, and the signal transmission efficiency with respect to communication time deteriorates. [0005] Therefore, in view of these points, an object of the present invention is to combine information signals from a plurality of points into one signal in a signal multiplexing system.
An object of the present invention is to provide a signal transmission method that can further improve transmission efficiency than conventional methods when transmitting to one device. [0006]

[Means for Solving the Problems] In order to achieve the above object, the present invention provides a signal system for transmitting data signals from a central device to a plurality of devices in fixed formats 1 to 1 through a multiplex transmission method. In the transmission method, when transmitting a signal to a specific device with a small number of data signals, dividing the data signal portion of the format and assigning each divided portion of the data signal portion to a plurality of different specific devices;
The central device creates a transmission signal in which each division of the data signal section corresponds to a data signal to be transmitted, and simultaneously transmits the created transmission signal to the plurality of specific devices. Each of the specific devices receives the transmission signal of the transmission, and extracts the data of the divided portion assigned to itself from the received transmission signal. [0007]

According to the present invention, an unused portion of a conventional transmission signal is allocated to another specific device, and is simultaneously transmitted to a plurality of devices. A specific device extracts data signals of predetermined divided parts from the received signal. Therefore, the overall signal transmission time is shortened by combining data signals to be transmitted to multiple devices into one transmission signal. Furthermore, the unused portion of the transmitted signal is also reduced. [0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Prior to explaining the present invention, a system configuration employing a signal transmission method will be explained with reference to FIG. [0009] In FIG. 2, a center unit (central device) 3 and controlled devices 4 of A to C are commonly connected to a signal line, and signals are transmitted from the center unit 3 to the three controlled devices 4 in a fixed order. It will be done. [00103 In this embodiment, the number of signals transmitted to the controlled devices A and B is 4 bits each, and the number of signals transmitted to the controlled device C is 8 bits. In this embodiment, the signal format shown in FIG. 1 is used only when transmitting signals to the controlled devices A and H at the same time. This signal format divides the conventional data (signal) part 1, and each divided part (4
bits). (0011) The signal transmission operation in the system configuration shown in FIG. 4 bits of data + 1 bit of parity) to the target device B is transferred onto the signal line S at time T1 in Fig. 3.The control target device A,
At B, when the transfer order °'1°' assigned to the own signal is confirmed, the signal on the signal line 5 is taken into the device. Each control device extracts 4 bits of the signal assigned to itself within this signal from the received signal. Next, time T in Figure 3
2, the center unit 3 transfers a signal (8 bits of data + 1 bit of parity) to be transmitted to the device C to be controlled onto the signal line 5. When the controlled device C confirms the second transmission, it receives the signal on the signal line 5 and takes it into the device as before. [o o After 121, the center unit 3 repeatedly executes the above-described processing procedure and transmits signals to the controlled devices A to C. In this embodiment, signals are transmitted to three controlled devices in two signal transmissions. On the other hand, in the conventional method, the number of signal transmissions is three times, so it is clear that the present embodiment shortens the signal transmission time and reduces the number of unused bit signals in one signal transmission. [0013] In addition to this example, the following examples are given. [0014] 1) In this embodiment, the signal transmission destination is specified by the signal transmission order, but in the case of a signal transmission method that adds an address part, a common address is assigned to the two controlled devices A and B. address, and adds this address to the transmitted signal. . [0015]

Effects of the Invention As explained above, the present invention not only contributes to shortening signal transmission time, but also allocates unused portions of conventional data to other specific devices, so that the device on the data receiving side can The effect is that the configuration can be made almost the same as the conventional configuration.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing the format of a transmission signal to a specific device according to an embodiment of the present invention.

FIG. 2 is a block diagram showing the system configuration of an embodiment of the present invention.

FIG. 3 is a time chart showing the timing of generation of a transmission signal according to an embodiment of the present invention.

FIG. 4 is an explanation showing the format of a conventional transmission signal.

Claims (1)

[Claims] Claim 1: In a signal transmission method in which data signals are transmitted in a fixed format from a central device to a plurality of devices using a multiplex transmission method, when transmitting a signal to a specific device with a small number of data signals, The data signal portion of the format is divided, each divided portion of the data signal portion is assigned to a plurality of different specific devices, and the central device corresponds to a data signal to be transmitted for each divided portion of the data signal portion. the created transmission signal is simultaneously transmitted to the plurality of specific devices, each of the plurality of specific devices receives the transmitted transmission signal, and transmits the generated transmission signal to the plurality of specific devices. A signal transmission method characterized by extracting data of a divided portion allocated to the self from among them.