JPH0431622Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a signal switching unit that switches signals using a relay.

[Conventional technology]

For example, a measurement system requires a switching unit that switches various signals using relays. Such a switching unit is constructed by mounting a plurality of relay cards on a mother card. In this case, if the relay drive signal of the relay card is, for example, 8 Bits, and 4 units (32 Bits) of signals are bus-wired on the motherboard of the switching unit, with these 8 Bits as one unit, which 8-Bit signal will be mounted on the card? It is necessary to select whether to use the signal as a relay drive signal.

In such cases, the conventional method used was to use jump wiring to switch where the 8-Bit input signal goes to the motherboard connector on the relay card side, but with this method, the compatibility of the relay card was reduced. There was a problem with it disappearing.

[Problems that the invention attempts to solve]

This invention was devised to solve these problems, and the purpose is to provide a flexible signal switching unit without making any special modifications to the relay card mounted on the motherboard. It is.

[Means for solving problems]

In order to achieve the above object, the present invention includes a plurality of relay cards equipped with relays for signal switching, and a relay drive that is configured with a predetermined number of bits as one unit and drives the relays. In a signal switching unit comprising a motherboard having bus wiring for passing signals and to which the plurality of relay cards are attached, the motherboard is provided with a number of digital switches corresponding to the relay cards, and each relay card is provided with one digital switch from the motherboard. A buffer with a tri-state configuration is provided, in which a relay drive signal for each unit Bit is input, and the on/off state of the digital switch is given as an enable/disable signal, and the relay drive signal for each unit is passed through or ignored. The structure is such that the passed drive signal is supplied to a relay drive circuit provided in each relay card. Examples will be described below.

〔Example〕

1 to 3 are configuration diagrams of embodiments of the signal switching unit according to the present invention, in which FIG. 1 is an electrical connection diagram of the main parts, FIG. 2 is a planar configuration diagram, and FIG.
The figure is a configuration diagram of the main parts viewed from an oblique direction. 1st
In the figures to FIG. 3, 10 is a motherboard;
20 is a relay drive card, 31 to 34 are respective relay cards, and these serve as relay unit 4.
0 is configured. relay drive card 20
and relay cards 31 to 34 are respectively motherboard 1
It is mounted on this motherboard via connectors 51 to 55 provided at 0. motherboard 1
0, a signal line 60 of 4 units of 32 bits each having 8 bits as a relay card drive signal line is wired as a bus. 71 to 74 are digital switches provided on the motherboard 10, respectively.

81 to 84 each have a tri-state output configuration.
8Bit buffer IC, each IC is relay card 3
1 to 34, respectively. motherboard 1
A relay drive signal line 60 whose unit is 8 bits provided at 0 is connected to the input terminals of buffers 81 to 84 for each unit. 81a to 84a are output enable (ENBLE) of buffers 81 to 84.
Signal terminals 81b-84b are respective enable pull-up resistors. Enable signal terminal 81a~
84a are connected to digital switches 71 to 74 provided on the motherboard 10, respectively. The other ends of the digital switches 71 to 74 are connected to a common potential point 100, respectively. The outputs of the buffers 81 to 84 are connected to a relay drive circuit 90 provided in the relay card 31 via bus wiring 61, respectively. Relay card 32~
34 also has exactly the same configuration as the relay card 31.

In such a configuration, the relay drive card 20 supplies a total of 32 bits of relay drive signals in units of 8 bits 4 to all the bus wiring 60 in parallel.
In this case, by manually turning on a desired one of the digital switches 71 to 74 provided on the motherboard 10, for example, switch 71, the buffer 81 of the relay card 31 corresponding to that switch 71 is enabled. This relay card 3 on the motherboard 10
An 8-bit drive signal corresponding to 1 is input to the relay drive circuit 90. In this case, the digital switches 72 to 74 are in the off state and the input buffer 8 is
Since 2 to 84 are in the disabled state, the other 24-bit relay drive signals are ignored. In this way, in the present invention, which 8-bit signal is to be used is determined by turning on the digital switch provided on the motherboard 10 for 1 bit. In this case, in the present invention, by making multiple relay cards compatible with each other by having the same configuration including a tri-state buffer, even if one relay card becomes defective, It is extremely convenient because you can simply replace it with another relay card without having to rewire the jamb wires like in the case of .

In addition, by using the present invention, for example, 4
If you want to switch the current switching relay and voltage switching relay at the same time, such as when measuring wire systems, you can turn on the same bit on the digital switch.
It has the feature that two cards can be operated simultaneously using the same drive signal.

[Effect of idea]

As explained above, in the present invention, multiple relay cards each have a tri-state buffer and have the same configuration, and the buffer enable control is selected by setting a digital switch on the motherboard. Therefore, the relay card can be made compatible without any special modifications or settings, and a flexible signal switching unit can therefore be realized.

[Brief explanation of the drawing]

1 to 3 are configuration diagrams of embodiments of the signal switching unit according to the present invention, respectively. FIG. 1 is an electrical connection diagram of the main parts, FIG. 2 is a planar configuration diagram, and FIG.
The figure is a configuration diagram of the main parts viewed from an oblique direction. 10...Motherboard, 20...Relay drive card, 31-34...Relay card, 40...
...Signal switching unit, 71-74...Digital switch, 81-84...Tri-state buffer.

Claims (1)

[Claim for Utility Model Registration] A plurality of relay cards equipped with relays for signal switching, and a bus configured with a predetermined number of bits as one unit and passing relay drive signals to drive the relays. In a signal switching unit consisting of a motherboard having wiring and to which the plurality of relay cards are attached, the motherboard is provided with a number of digital switches corresponding to the number of relay cards, and each of the relay cards is provided with digital switches corresponding to the number of digital switches from the motherboard. A relay drive signal is input, and the on/off state of the digital switch is given as an enable/disable signal, and a tri-state configuration buffer is provided for passing or ignoring the relay drive signal for each unit bit. A signal switching unit characterized in that the signal switching unit is configured to supply drive signals to relay drive circuits provided in each relay card.