JPS586080Y2 - No power scanner - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement of a scanner for capturing a large number of measurement data at remote points by switching sweeps.

In automatic control equipment and remote measuring equipment, a large number of data at a remote point is sequentially connected to a data signal line by a scanner.
A method of coupling to base equipment by cable is widely used.

Conventional scanners are generally configured with a large number of relays, and power for operating the relays is supplied at the location where the scanner is installed.

For this reason, it is necessary to wire a power supply to the scanner installation point, which may be undesirable from a safety and economical point of view depending on the nature of the plant to which this is applied.

The present invention improves on this by providing a scanner that does not require power supply at the scanner installation point, but can be powered by a signal cable connected to the base equipment.

In this invention, a transistor collector circuit is connected in series with the relay winding, a signal line is given to the base of this transistor, the power supply side of the collector circuit is condensed and connected to a cable, and a power source synchronized with the signal line is connected to the collector circuit. This makes it possible to supply power through a normal signal cable.

This will be explained in detail below using the drawings.

FIG. 1 is a circuit diagram of a device according to an embodiment of the present invention.

In the figure, 1 is the scanner box, 2 is the cable, 3 is the driver, and 4
5 represents a controller, 5 represents a data line, and 6 represents a repeater.

The scanner box 1 is installed near the measurement point, and the driver 3 and controller 4 are installed at the base station.

A multi-core cable 2 connects these parts.

The length of cable 2 is within the same plant and is approximately 500 m.

A large number of data electrical signals are coupled to the scanner box 1, which are switched and swept one by one as shown by dotted lines and coupled to a data line 5.

The data line 5 is coupled to, for example, an information processing device (not shown) via a repeater 6.

Further, a control signal is coupled to the controller 4 from the information processing device.

This is in turn led to a driver 3, which is configured to drive the device of the scanner box via the cable 2.

FIG. 2 is a block diagram showing the controller 4 of the apparatus according to the present invention.

The control signal is applied to terminal 41 in binary code.

This is converted into a decimal code by the decoder 42, and the logic circuit 4
given to 3.

The logic circuit 43 is necessary when more than 10 pieces of data are to be swept, and is a simple circuit for translating decimal codes.

This control signal switches the number of transistors 44 corresponding to the data input.

FIG. 3 is a circuit diagram showing the driver 3 portion of the device according to the embodiment of the present invention.

The figure shows only one element, and similar circuits are provided as many as the number of data inputs.

Terminal 45 shown in FIG. 2 is coupled to terminal 31 shown in FIG. 3.

32 is a photocoupler, which separates the scanner side and the power supply circuit.

33, 34, and 35 are resistors.

The transistor 36 is driven by the output of the photocoupler 32 to perform a switching operation, and its output is connected to the terminal 31.
It is connected to the signal line, which is the core wire of the cable 2.

FIG. 4 is a circuit diagram showing the scanner box 1 of the apparatus according to the present invention.

Reference numeral 11 denotes data inputs, each of which is connected to the data line 5 via a relay contact 12.

A relay winding 13 that drives this relay contact 12 is coupled in series between a power supply line 7 and ground via a diode 14 and a collector-emitter of a transistor 15.

A Zener diode 16 is connected to the base of the transistor 15.
, a resistor 17, and a diode 18, and are coupled to each output terminal 37 of the driver 3 by a signal line of the cable 2.

The power supply line 7 is condensed from the emitter circuit of each transistor 15 and connected to the power supply 38 of the driver 3 via the core wire of the cable 2.
is combined with

39 indicates a power supply switching circuit.

To explain the operation of such a device, the control signal of the information processing device is translated, and the driver output terminal 3 of the corresponding circuit is
A selection signal is sent to 7.

When the selection signal becomes sufficiently stable, the power supply opening/closing circuit 39 is closed for a short fixed period of time in synchronization with the selection signal.

This causes the corresponding transistor 15 to conduct, allowing current to flow through the relay winding 13 and closing the relay contact 12.

At this time, the corresponding data line 11 is connected to the data line 5, and the data is taken into the information processing device via the repeater 6.

At this time, in the embodiment shown in the figure, the current flowing through the power supply line 7 is approximately 35 mA, and the voltage of the power supply 38 is approximately 28V.

This level of current or voltage cannot be applied to the core wire of cable 2 (0
, 7 mmφ), the voltage drop is about 2 V or less, and there is no effect on the operation of the device.

As mentioned above, according to the present invention, ■ Since the scanner box does not require a power supply, the installation location can be freely chosen, increasing safety. ■ The power supply is transmitted in synchronization with the selection operation. It has advantages such as: ■ It does not add noise to the measurement signal; ■ It can use extremely common cables such as 0.7 mm φ multi-core cable; ■ It uses a contact relay, so it can be used for input from thermocouples. It has a positive effect.

[Brief explanation of drawings]

FIG. 1 is a circuit configuration diagram of an embodiment of the present invention. FIG. 2 is a configuration diagram of the controller portion of the embodiment of the present invention. FIG. 3 is a circuit diagram of one element of the driver section of the embodiment of the present invention. FIG. 4 is a circuit diagram of the scanner box portion of the embodiment of the present invention. 1...Scanner box, 2...Cable,
3...Driver, 4...Controller, 5.
...Data line, 6...Repeater, 7...
...Power line, 11...Data input, 12...
...Relay contact, 13...Relay winding, 1
4... Diode, 15... Transistor, 16... Zener diode, 17...
...Resistor, 18...Diode, 31...
...Terminal, 32...Photocoupler, 33.
34, 35...Resistor, 36...Transistor, 37...Signal line terminal, 38...
...Power supply, 39...Power switching circuit, 41...
...Control input, 42...Decoder, 43...
...Logic circuit, 44...Transistor, 4
5...Output terminal.

Claims (1)

[Scope of Claim for Utility Model Registration] A scanner box comprising: a base station device; a scanner box disposed near a measurement point away from the base station; and a multicore cable connecting the base station device and the scanner box; A plurality of data input terminals, a relay contact provided for each data input terminal and inserted between the data input terminal and the data output terminal, and a relay winding that drives each of the relay contacts, A transistor whose collector circuit is connected in series with this relay winding, a power supply circuit that connects the power supply side of the collector and emitter circuit of this transistor in common and leads it to a power supply terminal, and a plurality of transistors corresponding to the base electrode of the above transistor. a base circuit provided between the signal line connection terminal and the signal line connection terminal, and the multicore cable includes a data line connected to the data output terminal, a power line connected to the power supply terminal, and the plurality of a plurality of signal lines respectively connected to the signal line connection terminals of the base station apparatus, and the base station apparatus includes a repeater that relays and outputs the signal of the data line; A power-free scanner comprising: a control circuit that provides a signal; and a power switching circuit that provides a power supply current to the power line in synchronization with the selection signal.