JPH06167362A - Master-slave switching type measuring instrument - Google Patents

Abstract

PURPOSE:To allow easy and positive switching between master and slave sides by automating the switching. CONSTITUTION:When the ground on the side of external host unit is connected with an interface circuit 1, input signal to a master-slave selection circuit 8 goes to a low level thus turning a master circuit 3 and buffer circuits 4a, 4b automatically on. A slave circuit 5 and buffers 6a, 6b are turned off and a measuring instrument is switched to master side through function of the master circuit 3 and a measuring circuit 7. When the external host unit is disconnected, input signal to the master-slave selection circuit 8 is pulled up to a high level thus turning the master circuit 3 and the buffers 4a, 4b off. Consequently, the slave circuit 5 and the buffers 6a, 6b are turned an and the measuring instrument is switched to the slave side through function of the slave circuit 5 and the measuring circuit 7.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a master / slave switching type measuring device for automatically switching master / slave.

[0002]

2. Description of the Related Art In recent years, in a measuring instrument having a master / slave function, when a plurality of measuring instruments are connected and used, a host device is not used to externally control each measuring instrument.
That is, master / slave control is performed by using one unit as a master and connecting another measuring device as a slave.

FIG. 3 shows the configuration of a conventional measuring instrument having a master / slave function. In FIG. 3, reference numeral 1 is an interface circuit that performs processing when performing control from the outside. Reference numeral 2 is an interface circuit connecting the measuring instruments, 3 is a master function, and a master circuit for controlling the slave side by external control, and 4a and 4b are buffers.
Reference numeral 5 is a slave circuit having a slave function and serving as an interface portion with the control from the master side, and 6a and 6b are buffers. Reference numeral 7 is a measurement circuit for processing a predetermined measurement, 8 is a master / slave selection circuit for selecting a master / slave, and 9 is an external switch for switching the master / slave setting.

Next, the operation of this conventional configuration will be described. First, when the measuring device is set to the master side through the master / slave selection circuit 8 by the external setting switch 9, an external host device such as a computer (not shown) is connected to the interface circuit 1 under the control of the outside, and the master device is connected. A control signal is sent to the circuit 3.
The master circuit 3 to which the control signal has been input has the buffers 4a,
A control signal from an external host device is sent to a measuring instrument (not shown) slave-connected by the measuring circuit 7 or the interface circuit 2 between the measuring instruments via 4b. In this case, the buffers 4a and 4b are turned on (ON) and the buffers 6a and 6b are turned on.
Also, the slave circuit 5 is turned off. That is, the measurement device becomes the master side by the operation of the master circuit 3 and the measurement circuit 7.

In addition, the external setting switch 9
When the measurement device is set to the slave side by the slave selection circuit 8, the measurement device is connected to the measurement device on the master side (not shown) through the interface circuit 2 and communicates with the external host device (not shown) through the master side.
In this case, the master circuit 3 and the buffers 4a and 4b are
In the F state, the slave circuit 5 and the buffers 6a and 6b are O
The N state is set. That is, the measuring device becomes the slave side by the operation of the slave circuit 5 and the measuring circuit 7.

[0006]

However, in the above-mentioned conventional example, the user must be consciously setting the measurement device to the master side or the slave side by operating the external setting switch 9 together with the connection with the external measurement device. There was a problem of not becoming.

The present invention is to solve such a conventional problem and is an excellent master in which the master side or the slave side is automatically switched and the master side or the slave side can be easily and surely switched. -The purpose is to provide a slave switching type measuring device.

[0008]

In order to achieve the above object, the master / slave switching type measuring device of the present invention comprises:
A master circuit that has multiple interface circuits that perform connection processing with external measuring instruments and a master function that controls the external measuring instrument on the slave side by external control, and a slave function that controls from the master side. A slave circuit that performs interface processing with and a measurement circuit that performs measurement processing,
When the master / slave selection circuit that selects the master / slave and the measurement device is used as the master side or the slave side, the connection of the external control bus between the measuring instruments or the external host device side is judged and A master / slave automatic switching means for switching the measuring device to the master side or the slave side is provided.

[0009]

In the master / slave switching type measuring device of the present invention having such a configuration, when the measuring device is used as the master side or the slave side, the connection of the external control bus between the measuring instruments or the external host device side is performed. Since the measuring device is judged and automatically switched to the master side or the slave side, the master side or the slave side is automatically switched, and the master side or the slave side can be easily and surely switched.

[0010]

Embodiments of the master / slave switching type measuring apparatus of the present invention will be described in detail below with reference to the drawings.

FIG. 1 shows the configuration of an embodiment of a master / slave switching type measuring apparatus of the present invention. In FIG. 1, reference numeral 1 is an interface circuit for performing processing when controlling from the outside. Reference numeral 2 denotes an interface circuit for connecting between external measuring instruments, 3 has a master function, and master circuits for controlling the slave side by external control, 4a and 4b are buffers. Reference numeral 5 is a slave circuit having a slave function and performing interface processing with control from the master side, and 6a and 6b are buffers. Reference numeral 7 is a measurement circuit, 8 is a master / slave selection circuit for selecting a master / slave, and 10 is a connection line to the external host device side that functions as an external selection switch.

FIG. 2 shows the connection between the external host device side and the master / slave selection circuit 8. In FIG. 2, S11 is a connection signal, 13 is an external host device, and a connection signal from the external host device side 13 S11 uses the ground signal.

Next, the operation of the configuration of this embodiment will be described. In FIG. 1 and FIG. 2, when the measurement device shown in FIG. 1 is set as the master side, connection with the external host device 13 side is performed. In this case, by connecting the ground (GND) on the external host device 13 side to the interface circuit 1 as shown in FIG. 2, the signal input to the master / slave selection circuit 8 becomes low (L) level. When the interface circuit 1 is connected to the ground (GND) on the external host device 13 side, the measuring device is automatically switched to the master side. That is, the master circuit 3 and the buffers 4a and 4b are turned on. Further, the slave circuit 5 and the buffers 6a and 6b are turned off. As a result, in the measuring device, the master circuit 3 and the measuring circuit 7 operate and become the master side.

Further, when the connection with the external host device 13 side is disconnected, the signal input to the master / slave selection circuit 8 is pulled up, and becomes a high (H) level, and the measuring device is automatically slaved. Switch to the side. That is, the master circuit 3 and the buffers 4a and 4b are turned off, and the slave circuit 5 and the buffers 6a and 6b are turned on. As a result, the measuring device is operated by the slave circuit 5
And the measuring circuit 7 operate to become the slave side.

In this embodiment, the structure of the internal buffer etc. does not matter. In addition, the external host device 13
The circuit configuration for detecting the connection with the side is not limited to the configuration of this embodiment. For example, when a switch or the like is provided on the connector and the connector is connected to the apparatus, this switch may be automatically turned on to switch between master and slave.

[0016]

As is apparent from the above description, the master / slave switching type measuring apparatus of the present invention can be used as a master side or a slave side when the measuring apparatus is used between measuring instruments or an external host apparatus side. Since the measuring device is automatically switched to the master side or the slave side by judging the connection of the external control bus, the master side or the slave side is automatically switched, and the master side or the slave side is switched. It has an effect that it can be done easily and surely.

[Brief description of drawings]

FIG. 1 is a block diagram showing the configuration of an embodiment of a master / slave switching type measuring device of the present invention.

FIG. 2 is a configuration diagram for explaining the embodiment and showing a connection state between an external host device side and a master / slave selection circuit.

FIG. 3 is a block diagram showing a configuration of a conventional measuring instrument having a master / slave function.

[Explanation of symbols]

 1, 2 Interface circuit 3 Master circuit 4a, 4b, 6a, 6b Buffer 5 Slave circuit 7 Measurement circuit 8 Master / slave selection circuit 10 Connection line 13 External host device S11 Connection signal

Claims (1)

[Claims] 1. A plurality of interface circuits for performing connection processing with an external measuring instrument, a master function, a master circuit for controlling an external measuring instrument on a slave side by external control, and a slave function, A slave circuit that performs interface processing with control from the master side, a measurement circuit that performs measurement processing, a master / slave selection circuit that selects a master / slave, and when using the measurement device as the master side or the slave side. A master / slave switching type measuring device comprising a master / slave automatic switching means for determining connection of an external control bus between measuring instruments or to an external host device side and automatically switching the measuring device to a master side or a slave side.