JPH0454279B2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a measuring device connection network,
Specifically, a plurality of measuring instruments are connected so that sequence control related to measurement can be performed between the measuring instruments.

(Prior Art) The IEEE488 bus (GPIB) is generally used to construct a measurement system by connecting multiple measuring instruments via a bus.

Additionally, many digital voltmeters (hereinafter referred to as DMM) are equipped with an external special start signal input terminal and an A/D conversion end signal output terminal, and the input switch also has a start signal output terminal and an end signal input terminal. Some have these input switchers and DMMs.
Simple measurement sequence control can be performed in combination with

(Problem to be solved by the invention) However, the main purpose of the former GPIB is to exchange data between devices connected to the bus, and because bus control is complicated, it is not suitable for control purposes. computer is required. And something like this
When performing measurement-related sequence control in a measurement system built with GPIB, it is important to consider the waiting time unique to each measuring device, for example, in the case of an input switch, the actual waiting time in response to an input switching command. This is inconvenient because the time required for the switch to settle must be programmed in advance.

On the other hand, the latter combination of an input switch and a DMM uses an input switch to switch only the output of multiple devices under test, such as when measuring the output voltage of a Zener diode reference voltage source or the zero-drift voltage of an operational amplifier. It is sufficiently effective for measurements. However, in order to measure the linearity of multiple operational amplifiers or A/D converters, for example, the output voltage of a voltage generator must be applied to the object under test.
It is necessary to connect the voltage generator, input switch, and DMM in cascade, and measurement control cannot be performed using the current two cables.

The present invention has focused on these points, and its purpose is to provide a measuring device connection network that can perform measurement sequence control using a plurality of cascade-connected measuring devices with a relatively simple configuration. .

(Means for Solving the Problems) The measuring device connection network of the present invention has a master trigger terminal, a first A connector having a slave trigger terminal, a second slave trigger terminal, a first busy terminal, a second busy terminal, and a common terminal, a node setting mechanism for selectively setting a master node or a slave node, and a first slave trigger terminal. A first switch that connects the terminal and the second slave trigger terminal and whose contacts are opened when the power is turned on, and a second switch that connects the first busy terminal and the second busy terminal and whose contacts are opened when the power is turned on. Connect the master trigger terminals of the measuring instruments with the first cable, and connect the common terminals with the second cable.
cable, and connect the first slave trigger terminal and second slave trigger terminal of the adjacent measuring instrument to the third slave trigger terminal.
Connect the 1st busy terminal and 2nd busy terminal of the adjacent measuring device to the 3rd busy terminal with the 4th cable.
It is characterized by being connected in the same direction as the cable.

(Example) Hereinafter, an example of the present invention will be described in detail using the drawings.

FIG. 1 is a circuit diagram showing one embodiment of a bus interface of a measuring instrument used in the present invention. In FIG. 1, 1 is a connector, and the connector 1 includes a master trigger terminal T ₁ , a first slave trigger terminal T ₂ , a second slave trigger terminal T ₃ , a first busy terminal T ₄ , and a second busy terminal. T ₅ and common terminal T ₆ are provided. 2 is a first switch that connects the first slave trigger terminal _T2 and the second slave trigger terminal _T3 , and the contact is normally closed and opened when the power is turned on. 3 is a second switch that connects the first busy terminal T ₄ and the second busy terminal T ₅ ; the contact is normally closed like the first switch 2, and is opened when the power is turned on.
4 is a node setting mechanism that selectively sets the node to be a master node or a slave node;
The output signal is applied to the input/output control section 5. This input/output control unit 5 includes a node setting mechanism 4.
In addition to the output signal, a master trigger signal, ready signal, and trigger selection signal are added from inside the setting device. Then, a start signal and an end signal are outputted from this input/output control section 5 to the inside of the measuring instrument. Note that the end signal is valid only when the measuring instrument is used as a master node, and the trigger selection signal is valid only when the measuring instrument is used as a slave node. Reference numeral 6 denotes a driver/receiver, which is connected between the connector 1 and the input/output control section 5 and receives a master trigger signal, a first slave trigger signal, a second slave trigger signal, and a first slave trigger signal.
Transmits and receives a busy signal and a second busy signal.

Figure 2 shows connectors 1a to 1 between multiple measuring instruments.
It is a connection explanatory diagram of C. Connector 1a of each measuring instrument
The master trigger terminals T ₁ of ~1c are connected to each other by the first cable L ₁ , and the common terminals T ₆ to each other are connected to the second
The first slave trigger terminal T ₂ and the second slave trigger terminal T ₃ of the adjacent measuring instrument are connected by a third _cable L ₃ , and the first busy terminal T ₄ of the adjacent measuring instrument and the second busy terminal
T ₅ is connected by a fourth cable L ₄ to the third cable L ₃ in the same direction.

In such a configuration, the measuring instrument set as the master node makes the master trigger signal output to the master trigger terminal _T1 true at the same time as the start of measurement, and outputs a start signal to the internal circuit. When the internal circuit becomes ready, the first slave trigger signal output to the first slave trigger terminal _T2 becomes true, and the second slave trigger signal output to the second slave trigger terminal _T3 also becomes true. . In this way each slave trigger terminal
After m seconds have passed since each slave trigger signal output to T ₂ and T ₃ becomes true, _the first busy terminal
Observe the busy terminal _T5 , and if each signal becomes false, proceed to the next preset step.

On the other hand, the measuring device set as a slave node operates as follows. First, before starting measurement, a trigger selection signal is used to select and set whether to be activated by a master trigger signal or a slave trigger signal. Each slave trigger signal system and each busy signal system are both set to input mode until either the first slave trigger signal or the second slave trigger signal arrives.
Then, when either the first slave trigger signal or the second slave trigger signal arrives, the busy signal system of the signal system that arrived is set to output mode within n (n<m) seconds, and the output busy signal becomes true. . At this time, if it is set to be activated by a slave trigger signal, a start signal is output to the internal circuit. When the internal circuit becomes ready, or if it has become ready, other slave trigger signal systems are set to output mode and the output slave trigger signal is made true. Observe the busy signal of the signal system that is in input mode after outputting the slave trigger signal, and if it becomes false (or if it becomes false), check the busy signal of the signal system that is in output mode. make it false If it is set to be activated by a master trigger signal, a start signal is output to the internal circuit when the master trigger signal arrives. In this case, the busy signal will be output after the slave trigger signal arrives, similar to when activated by the slave trigger signal.

Figure 3 is a diagram showing an example of the connection between a master node and a slave node, in which a trigger signal is sequentially transmitted from the master node located at the bottom to the slave node located at the top. b shows a state in which the busy signal is sequentially returned from the slave node to the master node located below, and b indicates that the trigger signal is sequentially transmitted from the master node located in the center to the slave nodes located above and below. This shows a state in which the busy signal is sequentially returned from the slave nodes arranged above and below to the master node arranged in the center, and c indicates a trigger signal from the master node arranged above to the slave node arranged below. The figure shows a state in which busy signals are sequentially transmitted from the lower slave node to the upper master node.

Figure 4 shows that one of the i DMMs is the master node, and all the others are slave nodes, and multiple i DMMs are triggered simultaneously by the master trigger signal.
This figure shows a connection diagram when measuring the voltage of the measurement target DUT on the stand.

FIG. 5 is a timing chart for explaining the operation of FIG. 4, and all signals are assumed to be L active. In FIG. 5, a to d are signals related to the master node, a indicates the output signal of the master trigger, b indicates the output signal of the slave trigger i, c indicates the input signal of the busy i,
d indicates a ready signal of the internal circuit. e～i
is a signal related to slave node 1, and e
indicates the input signal of slave trigger j, f indicates the output signal of busy j, g indicates the output signal of slave trigger i, h indicates the input signal of busy i, and i indicates the ready signal of the internal circuit. ing. j
~n is a signal related to the slave node (i-1), j indicates the input signal of slave trigger j, k indicates the output signal of busy j, l indicates the output signal of slave trigger i, m indicates a busy i input signal, and n indicates a ready signal of the internal circuit.

When the output signal of the master trigger becomes true, the ready signals of the internal circuits of the master node and each slave node become false (not ready) almost simultaneously, and A/D conversion for measurement is started. The ready signal of each node becomes true upon completion of A/D conversion. When the ready signal of the master node becomes true, the output signal of the slave trigger i of the master node and the input signal of the slave trigger j of the slave node 1 also become true.

Slave node 1 performs an AND operation between the input signal of slave trigger j and the ready signal of the internal circuit, and makes the output signal of busy j and the output signal of slave trigger i true only when both signals are true. . When the output signal of busy j of the slave node 1 becomes true, the input signal of busy i of the master node also becomes true. On the other hand, as the output signal of slave trigger i becomes true, the input signal of slave trigger j of slave node (i-1) also becomes true.

The slave node (i-1) performs a logical product of the input signal of this slave trigger j and the ready signal of the internal circuit, and outputs the output signal of busy j and the output signal of slave trigger 1 only when both signals are true. Make true. When the busy j output signal of slave node (i-1) becomes true, the busy i input signal of slave node 1 also becomes true. On the other hand, the slave node (i-1) observes the input signal of busy i at least m seconds after the output signal of slave trigger i becomes true. Here, since the slave node (i-1) is connected to the terminal, the input signal of busy i is always false. Therefore, the output signal of busy j is made false.

In this way, when the output signal of busy j of slave node (i-1) becomes false, the input signal of busy i of slave node 1 also becomes false, and subsequently the output signal of busy j also becomes positive.

Furthermore, as the output signal of slave node 1's busy j becomes false, the input signal of master node's busy i also becomes false, and the measurement operation by one activation of the master trigger ends. .

Figure 6 shows a voltage generator GOS outputting a predetermined voltage and applying it to a plurality of i measurement target DUTs (for example, operational amplifiers), and then switching the response output of each DUT using an input switch SCAN. A connection diagram for measurement is shown. In this case, the voltage generator GOS becomes the master node, and the input switches SCAN and DMM are respectively set to become slave nodes and activated by a slave trigger. That is, the input switch SCAN is configured to sequentially switch the response output of the DUT from 1 to i with one trigger, and outputs slave triggers one by one after a settling time associated with the switching.

FIG. 7 is a timing chart for explaining the operation of FIG. 6, and all signals are assumed to be L active. In FIG. 7, a to d are signals related to the master node GOS, where a indicates the output signal of the master trigger, b indicates the ready signal of the internal circuit, and c indicates the output signal of the slave trigger i. , d indicates the input signal of busy i.
e to i are signals related to the slave node SCAN, where e indicates the input signal of slave trigger j, f indicates the output signal of busy j, g indicates the ready signal of the internal circuit, and h indicates the slave trigger The output signal of i is shown, and i is the input signal of busy j. j to n are signals related to the snow node DMM, where j indicates the input signal of slave trigger j, k indicates the output signal of busy j, l indicates the ready signal of the internal circuit, and m indicates the slave trigger i. , and n indicates the input signal of busy i.

At the master node GOS, when the output signal of the master trigger becomes true, the ready signal of the internal circuit becomes false (not ready), and the ready signal becomes true after a certain settling time required for stabilizing the switching voltage. Become. When the ready signal becomes true, the output signal of slave trigger i also becomes true.

In the slave node SCAN, the input signal of the slave trigger j becomes true when the output signal of the slave trigger i of the master node GOS becomes true. When the input signal of slave trigger j becomes true, the output signal of busy j becomes true, and the ready signal of the internal circuit becomes false. As the output signal of busy j becomes true, the input signal of busy i of master node GOS becomes true. The ready signal becomes true after a certain settling time required to stabilize the input switching operation. When the ready signal becomes true, the output signal of slave trigger i also becomes true.

In the slave node DMM, the input signal of the slave trigger j becomes true when the output signal of the slave trigger i of the slave node SCAN becomes true. When the input signal of slave trigger j becomes true, the output signal of busy J becomes true, and the ready signal of the internal circuit becomes false. As the output signal of busy j becomes true, the input signal of busy i of slave node SCAN becomes true. The ready signal becomes true after a certain A/D conversion time required to stabilize the measurement operation. When the ready signal becomes true, the output signal of slave trigger i also becomes true. On the other hand, the slave node DMM observes the input signal of busy i when at least m seconds have elapsed since the output signal of slave trigger i became true. Here, since the slave node DMM is connected to the terminal, the input signal of busy i is always false. Now, make the output signal of busy j false.

Again in slave node SCAN, busy j
The input signal of becomes false because the output signal of busy j of the slave node DMM becomes false. The ready signal becomes false when the busy i input signal becomes false, and the ready signal becomes true after a certain settling time necessary for stabilizing the input switching operation. When the ready signal becomes true, the output signal of slave trigger i also becomes true.

Thereafter, output signals of a plurality of i DUTs to be measured are measured while exchanging slave triggers and busy signals with the slave node DMM.

After measuring a predetermined number of times in this way, the busy i input signal of the slave node SCAN becomes false, so that the busy j of the slave node SCAN becomes false.
The output signal of becomes false, then the master node
The GOS busy i input signal also becomes false. This completes the measurement operation by one activation of the master trigger.

In the above embodiments, the power source for driving the switches 2 and 3 may be provided from the master node. As a result, when switches 2 and 3 of a node are configured with semiconductor analog switches, switches 2 and 3 can be kept on even if the power of nodes connected to the bus is selectively turned off, and the power of the node can be kept on. Selectively turning it off does not affect overall bus operation.

Also, as shown in Figure 8, any connector of bus B
When node ND is removed from CN, that part of the node
Bus B becomes open because the parts corresponding to switches 2 and 3 of the ND disappear. Such inconvenience can be solved by preparing a receptacle RP as shown in FIG. 9 and fittingly connecting it to the corresponding connector CN.

(Effects of the Invention) As explained above, according to the present invention, it is possible to realize a measuring device connection network that can perform measurement sequence control using a plurality of cascade-connected measuring devices with a relatively simple configuration, and has practical effects. is big.

[Brief explanation of the drawing]

Fig. 1 is a circuit diagram showing one embodiment of the bus interface of the measuring instrument used in the present invention, Fig. 2 is an explanatory diagram of the connection of connectors between multiple measuring instruments, and Fig. 3 is the connection between the master node and slave node. Example diagram, Fig. 4 is a specific connection diagram of Fig. 3, Fig. 5 is a timing chart for explaining the operation of Fig. 4, Fig. 6 is also a specific connection diagram of Fig. 3, and Fig. 7 is a specific connection diagram of Fig. 3. 6 is a timing chart for explaining the operation of FIG. 6, FIG. 8 is an explanatory diagram of bus connection, and FIG. 9 is an explanatory diagram of the structure of a receptacle. 1... Connector, 2, 3... Switch, 4...
Node setting mechanism, 5... input/output control unit, 6... driver/receiver, B... bus, ND... node, RP... receptacle.

Claims (1)

[Claims] 1. When constructing a measurement system by connecting a plurality of measuring instruments via a bus, each measuring instrument has a master trigger terminal, a first slave trigger terminal, a second slave trigger terminal, and a first slave trigger terminal. Connect a connector having a busy terminal, a second busy terminal, and a common terminal, a node setting mechanism that selectively sets the node to be a master node or a slave node, and connect the first slave trigger terminal and the second slave trigger terminal and turn on the power. A first switch whose contacts are opened by the switch, and a second switch which connects the first busy terminal and the second busy terminal and whose contacts are opened when the power is turned on are provided. and connect the common terminals to each other.
cable, and connect the first slave trigger terminal and second slave trigger terminal of the adjacent measuring instrument to the third slave trigger terminal.
Connect the 1st busy terminal and 2nd busy terminal of the adjacent measuring device to the 3rd busy terminal with the 4th cable.
A measuring device connection network characterized by being connected in the same direction as the cable.