JPH02259952A - Bus line system - Google Patents

Abstract

PURPOSE:To remarkably reduce the number of harness drawn out from an arithmetic circuit unit and to simplify a wiring work by forming the structure of the harness between the arithmetic circuit unit and each input/output unit with bus line harness. CONSTITUTION:All of the plural I/O ports 5-7 for extension are connected to the bus line harness 31 in parallel, and an output element 11, a sensor 13 that is an input means, and a high voltage unit 12, etc., are connected to each I/O port for extension. And the I/O ports 5-7 are arranged in the neighborhood 1 of their input/output means. The number of each bus line of the bus line harness is fixed regardless of the number of I/O ports for extension, and it is possible to connect the I/O ports for extension to the bus line harness 31 to a maximum if the sufficient bus line driving capacity of the I/O port 30 in the arithmetic circuit unit 1 can be prepared. Thereby, the bus line harness 31 can be managed with a few number of harness, and the wiring work can be simplified.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention This invention relates to a pass line system for connecting an arithmetic circuit unit and a plurality of input/output means in a control system.

(b) Conventional technology Arithmetic circuit unit including CPU and I/O for controlling people means
In conventional control systems equipped with an O-boat, the I/O boat for input/output control is provided within the arithmetic circuit unit, so there is no connection between the input/output means and the arithmetic circuit unit.
A one-to-one connection is made using a wiring harness.

FIG. 2 is a block diagram of a conventional system.

In the figure, l is an arithmetic circuit unit, and the CPU in this unit l has RAM 3, ROM
4.

I/O boat 5-7. Driver 8~/O. It includes a decoder 11 for the address bus. The output means includes an output element 11 such as a crankshaft or solenoid, and a high pressure unit 12.
etc., and includes a sensor 13 as an input means.

Note that this system is a control system for a copying machine, and the high voltage unit 12 drives a charger and the like arranged around the photoreceptor.

As shown in the figure, for example, an output element 11 consisting of a clutch or a solenoid is connected to the arithmetic circuit unit 1 by a wire harness 20, and the high-pressure unit 1
2, a wire harness 21 is used for connection with the arithmetic circuit unit 1, and a wire harness 22 is used for connection between the sensor 13 of the input means and the arithmetic circuit unit 1. Normally, in today's so-called intermediate-level copying machines, the number of output means among the input and output means is about /O0~150.
Since the number of input means is about 0 to 150, all of those input/output means are wired one-to-one. However, in the conventional system as described above, as the number of input/output means increases, the number of wire harnesses increases proportionally. This increases the complexity of wiring work, makes it difficult to secure installation space for the wiring harness, and furthermore, the wiring harness circuit itself becomes complicated, making maintenance and inspection from the outside difficult. There was also.

An object of the present invention is to provide a pass line system that can solve the above problems by configuring a wire harness circuit with pass lines.

(d) Means for Solving the Problems This invention distributes expansion I/O ports near each of a plurality of input/output means, and connects these I/O ports with the I/O boats in the arithmetic circuit unit. It is characterized by being connected by a bus line harness.

(e) Effect In this invention, expansion I/O ports are distributed near each input/output means, and these expansion I/O ports and the I/O boat in the arithmetic circuit unit are connected by a bus line harness. Since the configuration is such that the number of bus line harnesses coming out from the arithmetic circuit unit does not change regardless of the number of input/output means. That is, data is received and transferred between the arithmetic circuit unit and each input/output means using an addressing method from the arithmetic circuit unit.

(f) Embodiment FIG. 1 is a block diagram of a control system to which the pass line system of the present invention is applied.

The arithmetic circuit unit 1 includes a CPU 2. RAM3゜ROM4
and ll/o boat 30. The internal buses within the unit are an address bus (ADR3) and a data bus (DATA).
), and a control bus (CNT), which is divided by a decoder 33 into I/O boats and memory. Note that in this embodiment, the arithmetic circuit unit 1 is composed of a single board;
In a system using a plurality of CPUs, the arithmetic circuit unit can be configured with a plurality of boards. In general, the speed of the CPU2 in the arithmetic circuit unit is such that a pulse width of /O00nsec to /O0nsec is used, and the pulses on ADR3 and DATA directly output from the CPU2 are also of the same degree of /O0nsec.
The pulse width is from 00nsec to /O0nsec. I
The /O boat 30 serves to reduce the signal speed to the extent described above. In other words, in this embodiment, since the bus line harness 31 is pulled out from the I/O boat 30, it is almost impossible from a pulse technology to place the signal pulse of the above speed directly on this bus line harness. Almost impossible. Therefore, the I/O boat 30 converts the above speed signal pulses into low speed pulses and places them on the bus line harness 31.The bus line harness 31 has six ADRS pass lines (AO -A5) and the -DATA pass line (
DO) and three CNT pass lines (IORD, l0W
R, RES) and four PWR (power supply) pass lines. Among these, the ADRS pass line carries the address data of the expansion I/O port connected to the bus line harness 31 and the input/output means connected to the port, and the DATA pass line carries the expansion I/O port that is enabled. /The receiver transmits data to and from the O boat. Further, the CNT path line issues a system reset signal to the enabled expansion I/O boat, and sends data that determines the input/output mode of the I/O boat. The number of these pass lines is determined by the number of input/output means, etc.

The bus line harness 31 includes a plurality of expansion I/Os.
All O boats 5 to 7 are connected in parallel, and each expansion I/
The O port has an output element 11. similar to the conventional system of FIG. Sensor 13, which is an input means. High pressure unit 1
2nd class is connected.

The expansion I/O boats 5 to 7 are distributed in the vicinity 1 of these input/output means.

Each of the expansion I/O boats 5 to 7 has its expansion I/O
The port serves as an input/output means like boat 5 (
If only an output element (output element) is connected, a decoder circuit for selecting a specific output means and a decoder circuit for selecting a specific output means and
It is provided with a latch means for storing the signal of the DATA bus line harness sent to it, whether it is to be turned on or off, and a driver circuit for sending the latch output to the output means serving as a load. In addition, if the expansion I/O boat is connected only to human power means (sensor 13) like boat 6, that boat has an input channel selector circuit for selecting the input means and a selected input channel. A driver circuit for sending the state of the input means to the DATA pass line of the bus line harness 31 is provided. In addition,
This driver circuit has output modes “L”, “H”,
It uses an IC that is set to one of three high-impedance modes to prevent data conflicts with other output drivers.

In addition, in FIG. 1, 32 is a power supply unit, which supplies necessary voltage to the arithmetic circuit unit 1.

In the above configuration, the arithmetic circuit unit 1 and each of the plurality of expansion I/O boats 5 to 7 are connected by only one bus line harness 31, and the number of each pass line of the bus line harness 31 is is a fixed number regardless of the number of expansion I/O ports. Therefore, if the I/O boat 30 in the arithmetic circuit unit 1 has sufficient pass line drive capability, any number of expansion I/O boats can be connected in parallel to the bus line harness 31. In this way, the number of bus line harnesses 31 can be as small as about /O, and there is no need to use wire harnesses of /O0 to 200 as in the prior art.

(g) Effects of the Invention As described above, according to the present invention, the wire harness structure between the arithmetic circuit unit and each input/output means uses a bus line harness, so that the harness coming out from the arithmetic circuit unit This has the advantage that the number of wires can be extremely reduced, wiring work is extremely simple, the installation space for the harness is also extremely small, and maintenance and inspection work are also extremely easy.

[Brief explanation of drawings]

FIG. 1 shows a block diagram of an embodiment of the present invention, and FIG. 2 shows a block diagram of a conventional control system. 1-Arithmetic circuit unit, 31-Bus line harness, 5-7-I/O port for expansion.

Claims (1)

[Claims] (1) Expansion I/O ports are distributed near each of the plurality of input/output means, and these I/O ports and the I/O ports in the arithmetic circuit unit are connected by a bus line harness. bus line system.