JP2504062B2 - Intermediary device for general-purpose bus connection of programmable controller - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a general-purpose bus connection mediation device used when connecting a programmable controller to a general-purpose bus such as a multibus or a VME bus.

<< Summary of the Invention >> In the intermediary device for connecting a general-purpose bus of a programmable controller according to the present invention, an operation of extracting transmission data is performed with respect to the programmable controller, and with respect to the communication controller for the general-purpose bus, it is extracted. By making a transmission request based on the transmitted transmission data, the mediation between the two is performed.

<< Conventional technology and its problems >> Conventionally, for example, "programmable
Controller application manual SYSMAC S series Tateishi Electric Co., Ltd., page 51 ", connects the programmable controller to a dedicated bus called SYSWAY through the host link unit, and connects the programmable controllers to each other via this dedicated bus. There is disclosed a system for exchanging data between a programmable controller and a host device such as a personal computer or a minicomputer.

In this dedicated bus, a host controller normally has a control right to perform bus arbitration by software control, and therefore a protocol adapted to such an arbitration system is also adopted in the host link unit.

Further, as shown in page 7 of the above-mentioned reference document, the control in the scanning type programmable controller is common processing, I / O refresh processing, remote I / O processing, arithmetic processing, PC link service processing. A series of processes such as upper link service processing and tool service processing are cyclically performed, and when the upper link service time arrives, the bus occupation is passed to the upper link device. As the processing of the above, wait for the HALT ready from the programmable controller, HALT the CPU of the controller, fetch the transmission data from the shared memory of the controller in that state,
The procedure to release LT is taken.

By the way, with the recent increase in the amount of data transfer, there is a demand to connect this type of programmable controller to a general-purpose bus such as a multibus (IEEE796) or VMEbus (IEEEP1014). The upper link unit uses a system that adjusts the bus by software control, so it is applicable to general-purpose buses such as multi-bus and VME bus that perform bus arbitration only by hardware. I can't.

On the other hand, in a conventional communication controller for making a connection to a general-purpose bus of this type, the operation of transmitting data to the general-purpose bus is started only after waiting for transmission data and a transmission request. Therefore, even if such a communication controller is inserted between the programmable controller and the general-purpose bus, the mutual connection cannot be performed smoothly.

That is, as described above, the programmable controller waits for the upper link service time to arrive, issues a HALT ready, and waits for the data to be fetched from its own shared memory, whereas the general-purpose bus communication controller On the side as well, since it is in a state of waiting for data to arrive and a transmission request to be given in the same manner, the programmable controller and the communication controller cannot match at all.

<Object of the Invention> An object of the present invention is to provide a general-purpose bus connection mediation device that uses an existing general-purpose bus communication controller and is capable of connecting a programmable controller and a general-purpose bus. is there.

<< Constitution and Effect of the Invention >> In order to achieve the above-mentioned object, the present invention waits for a HALT ready signal from the programmable controller, HALTs the CPU of the same controller, and then from that controller's shared memory. First means for performing a series of operations for taking out the transmission data and releasing the HALT of the controller after the completion of the fetching, and for giving a transmission request to the communication controller for the general-purpose bus based on the fetched transmission data And a second means for performing an operation.

With this configuration, it is possible to exchange data between the programmable controller and the general-purpose bus communication controller, and as a result, the programmable controller can be connected to the general-purpose bus via the intermediary device and the communication controller. A large amount of data can be transferred at high speed to a host device, another programmable controller, or the like.

<< Description of Embodiments >> FIG. 1 uses the intermediary device 1 according to the present invention to connect between a programmable controller 2 and a communication controller 3, whereby the programmable controller 2 is connected.
FIG. 3 is a block diagram showing an example in which is connected to a general-purpose bus 4.

As shown in the figure, the intermediary device 1 is mainly composed of a microprocessor, and has a program memory, a work memory, and an I / O.
It is composed of an 80188 system equipped with

The programmable controller 2 is composed of a 6809 system 20 which also includes a microprocessor, a program memory, a work memory, an I / O, etc. In particular, in the figure, only the shared memory 21 used for transmission control is shown. There is.

The communication controller 3 is an existing communication controller applied to a multi-bus, a VME bus, etc.
186 system 30. Particularly, in this embodiment, a dual port controller 31 and a dual port memory 32 are newly provided.

The dual port memory 32 is used as a temporary storage area in transmission control, and has a large capacity of 256 Kbytes.

Next, FIG. 2 is a flow chart schematically showing the control operation of the intermediary device 1, the programmable controller 2 and the communication controller 3, and the data transfer processing operation will be systematically described below with reference to this flow chart.

If some data arrives via the general-purpose bus 4 and is received by the communication controller 3 (step 301), the communication controller 3 immediately interrupts the intermediary device 1 and the communication controller 3 receives the data. The obtained data is taken out by the intermediary device 1, and thereafter the intermediary device 1 is in a state of waiting for a HALT ready (No at step 202).

In this state, the programmable controller 2
When the upper link service time arrives on the side and HALT ready is issued (step 101), the waiting in the intermediary device 1 is released (Yes in step 202), and the HALT signal is sent from the intermediary device 1 to the programmable controller 2. In response to this, HALT is confirmed on the programmable controller 2 side (Yes at step 102), and immediately H
The ALT state is set (step 103).

As a result, the bus of the programmable controller 2 is handed over to the intermediary device 1 side, and the intermediary device 1 retrieves the transmission data from the shared memory 21 and the received data retrieved from the communication controller 2 in the shared memory 21. Write in a predetermined area (step 204).

After that, if HALT release processing is performed (step 205),
The HALT on the programmable controller 2 side is released (step 104), and thereafter, common processing, I / O refresh processing, remote I / O processing, arithmetic processing on the programmable controller side until the next upper link service time arrives. PC link service processing is repeated.

On the other hand, on the side of the intermediary device 1, following the HALT cancellation processing, a data transmission request is given to the communication controller 3 based on the transmission data taken out from the shared memory of the programmable controller.

Then, on the communication controller side, in response to this data transmission request, the transmission data given from the intermediary device 1
The data is transmitted to the general-purpose bus 4 via the modem 39.

Further, particularly in this embodiment, since the data transfer between the intermediary device 1 and the communication controller 3 is performed via the large-capacity dual port memory 32, the transmission efficiency is high,
The ability of the general-purpose bus 4 can be fully utilized.

In the above data transmission / reception processing, the address buffers 11, 33, 35, 37 and the data transfer 12, 34, 36, 38
Is appropriately controlled by opening and closing.

As described above, according to this embodiment, the existing communication controller 3 can be used and data can be transmitted and received between the programmable controller 2 and the general-purpose bus 4. Therefore, the existing programmable controller can be used. A wider data transfer system can be constructed.

[Brief description of drawings]

FIG. 1 is a block diagram showing the configuration of a system to which the device of the present invention is applied, and FIG. 2 is a flow chart for explaining the operation of the device of the present invention. 1 ... Mediation device 2 ... Programmable controller 3 ... Communication controller

Claims (1)

(57) [Claims] [Claim 1] Wait for HALT ready from the programmable controller to HAL to the CPU of the controller
The first means for performing a series of operations for applying T to take out the transmission data from the shared memory of the same controller in that state, and releasing the HALT of the same controller after completion of the taking out, and the taken out transmission data, A general-purpose bus connection mediation device of a programmable controller, comprising: a second means for performing an operation of giving a transmission request to a general-purpose bus communication controller.