JPS61102850A - Using system of sentronics interface - Google Patents

Abstract

PURPOSE:To effectively use a sentronics interface by change-over controlling two gate means by a select-in signal of a sentronics interface and thereby using the sentronics interface with respect to two devices to be controlled. CONSTITUTION:A select-in signal of signal lines constituting a selectronics interface is directly applied to an NAND gate 2 and via an inverter circuit 12 to an AND gate 3. Accordingly, when the select-in signal is at a high level, a strobe signal showing a data reading permission is fed via the gate 2 to a printer side, and when the select-in signal is at a low level, the strobe signal is fed from the gate 3 to a controller 1, and via the controller 1 to other device as a control line. A signal indicating a reset in a printer and other device is also similarly fed to the printer side, or via the controller 1 to other device as the control line.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for utilizing a Centronics interface, and in particular, when a device connected to one Centronics interface is in an offline state, a device connected to another Centronics interface is connected to a Centronics interface. The present invention relates to a method for effectively utilizing a Centronics interface by enabling a device to operate.

[Conventional technology]

The Centronics interface was developed as an ink face in an 8-bit parallel transfer system for printers, and is widely used, but it is also widely used not only for printers but also as an ink face for various peripheral devices.

In general, the Centronics interface is used exclusively in a manner in which one device is connected to one Centronics interface and the device operates in an ink-faced manner.

[Problem that the invention seeks to solve]

In the conventional method of using the Centronics interface, when the device connected to the ink face is in an offline state, no signal transmission operation is performed, and therefore the interface is not used effectively. Furthermore, in order to operate multiple devices, the same number of ink faces are required, which imposes a heavy economic burden.

[Means for solving problems]

In the method of the present invention, signal lines for data transmission in the Centronics interface are inputted in parallel to two controlled devices, and each control signal output from the Centronics interface is switched to both controlled devices. A first gate means for transmitting control signals, and a second gate means for switching each control signal transmitted from both controlled devices and inputting the same to the Centronics interface. Performs switching control.

1 [Operation] In the method of the present invention, the signal line for data transmission in the Centronics interface is connected to two controlled t
ii in parallel, and performs switching control using the select-in signal of the Centronics interface, and switches and sends each control signal output from the Centronics interface to both controlled devices. Each control signal sent from the controller is switched and input to the Centronics interface.

〔Example〕

FIG. 1 shows the configuration of an embodiment of the method of using the Centronics interface of the present invention. In the same figure, l
is the controller, 2 is the Nant gate, 3 is the AND gate, 4 is the Nant gate, 5 is the Ant gate, 6 and 7 are the AND gate, 8 is the Noah gate, 9 and 10 are the AND gate,
11 is an OR gate, and 12 and 13 are inverter circuits.

In Figure 1, 8-bit data DATAO to DA constitute signal lines in the Centronics interface.
TA7 is input to a printer (not shown), and is also output as a signal line to other eye organs (not shown) via the controller 1.

Each control signal in the Centronics interface*
STB, *ILST, *ACK, and BUSY are switched through each of the gates 2 to 11 described above and inputted to a printer (not shown), and also to other devices (not shown) as control lines.

That is, the select-in signal (*5LCTIN) of the signal lines constituting the Centronics interface is applied directly to the Nant gate 2 and also to the AND gate 3 via the inverter circuit 2. Therefore, when the select-in signal (*5LCTIN) is at high level, the strobe signal (*5LCTIN) indicating permission to read data is
5TB) is sent to the printer side via gate 2, and when the select-in signal (*5LCTIN) is low level, the strobe signal (*STB) is sent from gate 3 to controller l, passes through controller 1, and is used as a control line. Sent to other devices. Similarly, the signal (*ILST) that instructs reset in printers and other devices is
Depending on whether the select-in signal (*5LCTIN) is at high level or low level, it is sent to the printer side (not shown) via the Nant gate 4 or AND gate 5, or sent to other equipment as a control line via the controller 1. sent to.

A response signal (*ACK) constituting a control line from the printer or other equipment indicating a response to permission to read data is sent from the printer or from the other equipment via the controller 1 and sent to the AND gate 6.7, respectively. However, the select-in signal <*5LC is input to gate 6.
T IN ) is applied directly, and the same signal is applied to the gate 7 via the inverter 13, so depending on whether the select-in signal (*5LCTIN) is at high level or low level, the output from the printer is determined. Alternatively, a response signal q (*ACK) sent from another device via the controller 1 is sent to the Centronics interface side. In addition, a busy signal (
BUSY) is sent from the printer or sent from another device via the controller 1 and is sent to the computer games 1-9,
10, but the select-in signal (*
5LCTIN) is at high level or low level, the busy signal (BU
SY) is sent to the Centronics interface side.

〔Effect of the invention〕

As explained above, according to the usage method of the Centronics interface of the present invention, the signal line for data transmission in the Centronics interface is inputted in parallel to two controlled devices, and the select-in signal of the Centronics interface Perform switching control,
Each control signal that makes up the control line output from the Centronics interface is switched and sent to both controlled devices,
In addition, each control signal that makes up the control line sent from both controlled devices is switched and input to the Centronics interface, so when one device connected to the interface is offline, the other device Therefore, the ink face can be used effectively. It is also economically advantageous because one Centronics interface is sufficient to operate two devices.

[Brief explanation of drawings]

The figure shows the configuration of an embodiment of the Centronics interface usage method of the present invention. 1-Controller, 2-Nant Gate, 3...A9.1
0.-and gate, 11...or gate, 12.1
3-Inverter circuit

Claims (1)

[Claims] A first gate means that inputs signal lines for data transmission in the Centronics interface to two controlled devices in parallel, and switches and sends each control signal output from the Centronics interface to both controlled devices. and a second gate means for switching each control signal sent from both controlled devices and inputting it to the Centronics interface, and controlling the switching of both said gate means by a select-in signal of the Centronics interface. A Centronics interface utilization method characterized by making the Centronics interface usable for two controlled devices by performing the following steps.