JPS60246149A - Data transmission equipment - Google Patents

Abstract

PURPOSE:To attain data transmission at high speed and with high frequency by providing a clock device to an on-duty controller and all devices to synchronize the system and transmit/receive data when an IEEE-std-488 or an IECTC66 (GP-IB) is used as an interface bus. CONSTITUTION:The on-duty controller 1 and devices 2-6 are provided with the clock device and an IFC signal serving as a managing line of the GP-IB matches the time of the on-duty controller 1 and all the devices 2-6. Thus, the on-duty controller 1 and each device state are synchronized at the right part from the IFC in Fig. In this state, what does each device at which state is programmed, and the access from the on-duty controller 1 can be allowed to respond immediately. In transmitting data, the on-duty controller 1 recognizes the state of the device at each data transfer by using the information added to the data and it is not required to access the device by polling prior to the transfer.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention provides an IEEE-s interface bus.
td-488 or IECTC66 (hereinafter referred to as CP-IB)
The present invention relates to an improvement of a data transmission device that exchanges data between a plurality of electronic devices using a computer (referred to as a computer).

[Prior art]

A conventional device of this type is shown in FIG. In the figure, 1 is the duty controller that manages GP-IB;
2 to 6 are devices that exchange data with the duty controller 1, and 7 to 9 are signals that control data exchange (in the standard, DAV, NRFD,
10 is a data bus, and signals not related to the present invention are omitted.

Next, the operation will be explained. First, before mutually exchanging data, the duty controller 1
In order to manage the status of devices 2 to 6, each device 2 to 6 is controlled by a parallel ball or a serial ball.
Check the status of.

This is data bus 10. Data is exchanged and checked (this is called a three-wire handshake) using control signals 7 to 9 and signals defined by the standard (this is called ATN) although not shown in the figure, and in this way, the controller on duty After device 1 recognizes the status of each device 2 to 6, data is exchanged with each other.

Conventional signal transmission equipment is configured as described above, so in order to know the status of devices 2 to 6, it is necessary to perform handshaking many times, and handshaking is performed using the slowest response according to the standard ( This has the drawback of wasting time preparing for data exchange, ie, checking the status of the device, since it is executed at the speed of the slow device.

(Summary of the Invention) This invention was made in order to eliminate the drawbacks of the conventional ones as described above.The on-duty controller and all devices are provided with a clock device, and the time of the clock device is set by a GP.
- The system is synchronized using the IFC signal, which is the IB control line, and the time signal of the clock device, and the transmission order and signal configuration are notified from the predetermined period or the on-duty controller to all devices. It is an object of the present invention to provide a data transmission device that can perform high-speed operation by transmitting data between the on-duty controller and each device according to the present invention.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to the drawings. The structure of the apparatus of the present invention is similar to that shown in FIG. FIG. 2 is a timing chart of an apparatus according to an embodiment of the present invention, and in the figure, A1-A4 are timing charts showing the operations of the on-duty controller and each device;
0.1, 2°3, . . . indicate the states set by the time signal of the clock device included in the on-duty controller and each device, and AI is the on-duty controller 1. A
2 is device 2. A3 is device 3. A4 is device 4
This is the state of

Now, device 2 is in state 0, 1, 2, 3°...
In all states of..., device 3 is in state 0゜2,...
...and device 4 is in state 1, 33...
. . , it is assumed that data is promised to be sent to the on-duty controller 1, and the states on the left side of FIG. 2 are different. That is, since they are not synchronized, even if the duty controller 1 accesses a device, it must wait until the device reaches the promised state.

Therefore, in this embodiment, as shown in FIG. 2, the time of the duty controller 1 and all the devices 2 to 6 is synchronized using the IFC signal, which is the control line of cpiB. Therefore, in the part to the right of the IFC in FIG. 2, the duty controller 1. The states of each device are all the same, that is, they are synchronized. In such a state, each device is programmed to know what state to do and what to do, so it can immediately respond to access from the duty controller 1.

Furthermore, when transmitting data, the structure of the signal is agreed upon in advance, and information indicating the status of the device, that is, whether it is operating normally, or whether the previous transfer was normal or abnormal, is added to the data. By sending this information, the duty controller 1 can use this information to know the status of the device each time data is transferred. Therefore, there is no need to access the device by polling or the like prior to transfer, and the work of the duty controller l is reduced. Further, depending on the information from this device, the duty controller 1 may select one of a plurality of predetermined programs, and thereby exchange data.

According to this embodiment, a clock device is provided in the on-duty controller and each device to synchronize the system and exchange data according to a predetermined program. Therefore, the status of the device can be checked by polling. Furthermore, this allows GP-IB, which was originally used in an asynchronous system with a bus speed matching the speed of the slowest device, to be used at extremely high speed operation. Also, as mentioned above, you can know the status of the device without polling, so
It is possible to configure a system that allows for high-frequency data exchange.

In the above embodiment, the system is synchronized by IFC, but the time adjustment and reset of the clock device may be performed using a normal talker/listener function, and the same effect as in the above embodiment can be obtained.

〔Effect of the invention〕

As described above, according to the data transmission device according to the present invention, the duty controller and all devices are provided with a clock device,
The system is synchronized by the clock device, and data is exchanged according to the transmission order and signal configuration agreement determined in advance or notified from the on-duty controller to each device, so the device status can be checked by polling. This has the effect of enabling very high-speed, high-frequency data transmission.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the configuration and signals of a conventional data transmission device and the present invention, and FIG. 2 is a timing chart showing the operation of the data transmission device according to an embodiment of the present invention. 1... Duty controller that manages GP-IB, 2-
6... CP-IB device, 7-9... Control signal for three-wire handshake (GP-IB),] 0.
・Data bus (GP-
IB). Agent Masuo Oiwa Figure 1 Figure 2

Claims (2)

[Claims] (1) IEEE-std as an interface bus
- In a data transmission device that uses IECTC66 (GP-IB) and transmits data between a duty controller that manages the interface bus and one or more devices, a clock device is provided between the duty controller and each device. The system is synchronized by the time signal of the clock device, and the data transmission order and signal configuration are predetermined or notified from the on-duty controller to each device, and the on-duty controller and each device are communicated. 1. A data transmission device characterized in that data transmission is performed using . (2) The data transmission device according to claim 1, characterized in that when transmitting data from each device to the on-duty controller, information indicating the status of each device is added and transmitted. .