JPH05128021A - Multiple signal transmitting equipment - Google Patents

Abstract

PURPOSE:To allow an operator to easily execute the contents check of a displayed analog signal and the detection of communication abnormality by providing this multiple signal transmitting equipment with an arithmetic processing means for converting the bit value of a digital signal into the level value of an analog signal and a display means for a converted value. CONSTITUTION:A microprocessor 1' executes communication control processing for transferring an inputted information signal to a center device. In addition, the microprocessor 1' reads out a processing procedure in each fixed period to read out an output signal (digital format) from an analog input circuit 5 and convert a bit value indicated by a digital signal into the level value of an analog input. A previously determined conversion formula is used for the conversion. A converted value is outputted to a display circuit 4 as a numerical code format. The circuit 4 converts the numerical code received from the microprocessor 1' into a dot pattern by means of a character generator and visually displays the level value indicated by the analog signal as a character code format by means of a liquid crystal display device or the like.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multiplex signal transmission apparatus for receiving an analog information signal from a connected device, converting the information signal into a digital signal and then a multiplex signal, and then transmitting the signal in a multiplex signal transmission system. Regarding

[0002]

2. Description of the Related Art Conventionally, when a programmable controller automatically controls a plurality of electronic devices, a multiple signal transmission device is provided between the device and each programmable controller, and the multiple signals are transmitted between the programmable controller and each multiple transmission device. Information signals are transmitted and received by a transmission method, and the information signals are transferred to the electronic device. In addition, the multiplex signal transmission device is installed when the information exchange between the center station and the plurality of devices is performed by the multiplex signal transmission method.

FIG. 3 shows a typical circuit configuration of a multiplex signal transmission device for inputting information in the form of an analog signal and converting it into a multiplex signal among such multiplex signal transmission devices.

In FIG. 3, when an information signal in the form of an analog signal is received at the analog input end from a connected device, this analog information signal is analog-digital converted (analog value → digital value) in the analog input circuit 5. , To the microprocessor 1.

The operator designates the station number (address) assigned to this multiple signal transmission device by the address switch 2. The designated station number is sent to the center device and used for subsequent designation of communication destinations.

The transmission interface 3 takes in the multiplex signal transmitted from the center station via the multiplex signal terminal, identifies the multiplex signal having the address assigned to the own station among the multiplex signals, and identifies the multiplex signal. Is transferred to the microprocessor 1 in the form of a digital signal. On the contrary, the information input from the connection device via the microprocessor 1 is sent to the center station by being carried on the multiplex signal including the address designation of the own station.

[0007]

In the conventional device of this type,
It had a function of detecting a communication error between the multiple signal transmission device and the center device. However, since the multiple signal transmission device and the connection device are generally detachable and can be connected to various devices in a versatile manner, they do not have a function of detecting a communication abnormality regarding an analog signal.

Therefore, during installation work and maintenance and inspection work,
The operator had to check the analog signal using an analog measuring instrument. Moreover, since the voltage level of the analog signal also differs depending on the specifications of the connected device, various measuring instruments had to be prepared.

Therefore, in view of the above points, an object of the present invention is to provide a multiplex signal transmission apparatus which has a simple structure and allows an operator to easily confirm the contents of an analog signal.

[0010]

In order to achieve such an object, the present invention receives an information signal exchanged between an electronic device and a center device from the electronic device in the form of an analog signal, In a multiplex signal transmission device for converting to a digital signal and then transmitting to the center device by a signal multiplexing method, an arithmetic processing means for converting a bit value indicated by the digital signal into a value indicating the level of the analog signal, and the conversion means. And a display means for displaying a value.

[0011]

The operator confirms the contents of the analog signal and detects the communication abnormality by displaying the analog input value displayed on the display means.

[0012]

Embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 1 shows a circuit configuration of an embodiment of the present invention.

In FIG. 1, the same parts as those of the conventional example of FIG. 3 are designated by the same reference numerals. Similar to the conventional example, the microprocessor 1'executes a communication control process for transferring the information signal input from the connected electronic device to the center device. In addition, the output signal (digital form) of the analog input circuit 5 is read by executing the processing procedure of FIG. 2 at regular intervals, and the bit value indicated by the digital signal is converted into the level value of the analog input. A predetermined conversion formula is used for this conversion. A process of outputting the converted value in the form of a numerical code to the display circuit 4 is performed.

In the display circuit 4, the microprocessor 1 '
The numerical code received from the device is converted into a dot pattern by a character generator (character generator), and the level value indicated by the analog signal is visually displayed in a character symbol form on a liquid crystal display or the like.

Therefore, each time the level of the analog signal changes, the level value is displayed on the display circuit 4.

Therefore, the operator can confirm the presence or absence of communication abnormality of the analog signal by looking at this display.

Although the microprocessor 1'performs the display control in this embodiment, the analog input circuit 5 is used.
The output signal of 1 may be directly output to the display circuit 4.

In this case, the character generator generates a dot pattern of an analog value corresponding to the bit value indicated by the output signal.

[0019]

As described above, according to the present invention, not only the communication abnormality between the multiple signal transmission device and the electronic equipment can be confirmed, but also the operator can confirm the signal content during the normal communication. can do.

[Brief description of drawings]

FIG. 1 is a block diagram showing a circuit configuration of an embodiment of the present invention.

2 is a flowchart showing a processing procedure executed by a microprocessor 1'of FIG.

FIG. 3 is a block diagram showing a circuit configuration of a conventional example.

[Explanation of symbols]

 1,1 'Microprocessor 2 Analog switch 3 Transmission interface 4 Display circuit 5 Analog input circuit

Claims (1)

[Claims] 1. Multiplexing in which an information signal transmitted and received between an electronic device and a center device is received from the electronic device in the form of an analog signal, converted into a digital signal, and then transmitted to the center device by a signal multiplexing method. The signal transmission device is provided with an arithmetic processing unit for converting a bit value indicated by the digital signal into a value indicating the level of the analog signal, and a display unit for displaying the converted value. Transmission equipment.