JPH03192454A - Data transfer device - Google Patents

Abstract

PURPOSE:To efficiently and speedily execute data transfer by counting the number of data frames prepared by a remote channel and suitably sending information showing the counted number to a local channel. CONSTITUTION:At a remote channel 300, a preparation completing data frame number counter 350 is provided to count the number of the data frames, and a transmission controller 360 is provided to send the count value to a local channel 100 when the count value reaches a value determined in advance. At the local channel 100, a transmission controller 150 is provided to calculate difference between the number of transfer request byte count frames, which are generated by a frame byte count generating circuit 180, and the sent count value and based on the difference, a byte count buffer 380 is controlled. Thus, the idle state of the byte count buffer at the remote channel can be immediately known and the data transfer is not interrupted.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application) The present invention relates to a transfer device having a remote channel and a local channel, and particularly relates to transfer request byte count buffer management when transferring data from a remote channel to a local channel.

(Prior Art) Generally, in a data transfer device, when transferring data from a remote channel to a local channel, a data transfer request byte count in units of data frames is sent from the local channel to the remote channel. In the remote channel, this data transfer request byte count is stored in a byte count buffer and read out. The remote channel creates a data frame based on the read transfer request byte count and stores it in the data buffer. It then reads this data frame and sends the data frame to the local channel. The local channel receives and accepts this transmitted data frame.
The local channel manages the byte count buffer of the remote channel based on the difference between the number of transfer request byte count frames and the number of transfer data frames described above.

(Problems to be Solved by the Invention) In the conventional data transfer device described above, when the local channel receives a transfer data frame, it determines that the data transfer request byte count frame has been used, and calculates the number of transfer request byte count frames and the transfer data. A countdown is performed to find the difference with the number of frames. However, if transfer request byte count frames are sent out continuously from the local channel, all transfer data frames are received even though the transfer request byte count frames are read from the byte count buffer. Until then, the local channel recognizes that the number of data frames stored in the data buffer is unused. Also, on the local channel, even if there is free space in the remote channel's byte count buffer.

As a result, the local channel assumes that the byte count buffer is full.

Transfer request byte count may not be sent.

As described above, the conventional data transfer device has a problem in that the byte count buffer of the remote channel is not used effectively, and data transfer is temporarily interrupted.

An object of the present invention is to provide a data transfer device in which data transfer is not interrupted.

(Means for Solving the Problems) The present invention includes a local channel connected to an input/output processing device, and a remote channel connected to the local channel and performing data transfer with a device control device, When transferring data from the remote channel to the local channel, a plurality of data transfer request/byte count frames indicating a data transfer request are provided from the local channel to the remote channel, and the data transfer request byte count is stored in a storage means. Been.

In the data transfer device that sequentially sends data frames to the local channel based on the data transfer request byte count frame, the remote channel includes a count means for counting the number of data frames, and a count value of the count means is predetermined. When the value is reached,
sending means for sending the count value to the local channel; the local channel is provided with calculating means for calculating a difference between the transfer request byte count frame number and the sent count value; There is obtained a data transfer device characterized in that the storage means is managed based on the data transfer method.

Further, the sending means may send a count value to the local channel when sending of the data frame is completed.

Further, the local channel determines to send the data transfer request byte frame based on the difference. (Embodiment) Next, the present invention will be described by way of an embodiment.

Referring to FIG. 1, a data transfer apparatus according to the present invention includes a local channel 100 and a remote channel 300. The remote channel 300 has an input/output (Ilo)
) controller 310. Data buffer (RDB) 3
20, frame transmission circuit 330° buffer controller 340 and 37o2 created data frame number counter (MDFC) 350, sending controller 360.
A byte count buffer (RBCB) 380 and a near +/- frame receiving circuit 390 are provided. Also, the local channel 100 is a frame receiving M SOO 1210
, data frame buffer (LDB) 120 , I
lo: +7) 0-la 130, high 7 ar y y)
Rollers 140 and 160. Transmission controller 150. Frame transmission circuit 170. frame byte callan) (BC
) generation circuit 180. and byte count buffer (LB
CB) is equipped with l90.

An input/output processing device (not shown) is connected to the local channel 100, and the input/output processing device provides a transfer request byte count to the local channel 100 in predetermined units. This transfer request byte count is write-controlled by the buffer controller 160 and is written to the LBC.
B 190.

Under read control of the buffer controller 160.

The frame BC generation circuit 180 reads the transfer request byte count from the LBCB 190 and converts it into a data transfer request byte count (ABC) in units of frames. This data transfer request BC is sent to the frame transmitting circuit 170.
sent to. In frame transmission circuit 170, a transfer request byte count frame is created from data transfer request BC, and this transfer request byte count frame is sent to a remote channel under the control of transmission controller 150.

As shown in FIG. 2, this transfer request byte count frame includes a transfer request byte count (ABC) and an identifier D1, and the identifier D1 indicates that it is a transfer request byte count.

In the remote channel 300, the frame receiving circuit 390 receives the transfer request byte count f1/-mu.

Then, the transfer request byte count is stored in the RBCB 380 under write control of the buffer controller 160. Thereafter, the controller 310 controls the buffer controller 370 to read the transfer request byte count from the RBCB 380.

By the way, a device control device (not shown) is connected to the remote channel 300, and the I10 controller issues a data transfer request to the device control device based on the transfer request byte count. The device control device retrieves data from the device based on the data transfer request (read).

Transfer read data to remote channel.

The I10 controller 310 receives and receives data.

A data frame is created based on the transfer byte count read from the RBCB 300. As shown in FIG. 3, this data frame is provided with an identifier D2 indicating that it is a data frame.

Furthermore, the data part (corresponding to the transfer request byte count)
, data frame number DFC, byte count indicating the number of valid data in the data frame) RBC. I1
0 controller 310 stores the data frame in RDB 320 under write control of buffer controller 340 . At this time, a drive command is given to the MDFC 350, and the MDFC 350 counts up.

For example, every time l data frame is written,
C350 is increased by +1.

The buffer controller 340 reads a data frame sequence from the RDB 320 under the control of the transmission controller 360 . This data frame sequence is provided to frame transmission circuit 330 and sent to local channel 100 under the control of transmission controller 360.

The data frame sequence is received by the 71/-me receiving circuit 110 and sequentially written to the LDB 120 under write control of the buffer controller 140.

Once a predetermined number of data frames have been written to the LDB 120, the buffer controller 140 sequentially reads them from the LDB 120 under the control of the frame receiving circuit 110.
I10 controller 130. And I1
0 controller 130 provides data frames to the input/output processing device.

By the way, when all the data frames written in the RDB 320 are read out, that is, when the frame transmission circuit 330 sends out all the data frames, it sends a transfer end signal to the transmission controller 360. The transmission controller 360 monitors the count number of the MDFC 350 and reads the count value to the frame transmission circuit 330 upon receiving the transfer end signal. At this time, MDFC350
will be reset.

The frame transmitting circuit 330 creates a data count frame shown in FIG. 4 based on this read count value. This data count frame is the frame number DFC and D
The frame has an identifier D3 indicating that it is an FC frame. This data count frame is then sent to the local channel 100.

This data count frame is sent to the frame receiving circuit 110.
to the transmit controller 150.

The DFC is subtracted from the transfer request byte count frame number given from the frame transmission circuit 170.

This makes it possible to know the status of the 79-item count buffer of the remote channel. and.

The local channel determines the number of transfer request count frames.

Note that the transmission controller 360 monitors the MDFC 350, and when the count value of the MDFC 350 exceeds a predetermined setting value, it stops reading data frames from the RDB 320 and switches the frame transmission circuit 330, so that the count value of the MDFC 350 stops. Read the value to the frame sending circuit 330.

Based on this, a data count frame may be transmitted. In this case, when the transmission of the data count frame is finished, reading of the data frame from the RDB 320 is restarted and the frame transmission circuit 330 is switched to the RDB 320 side.

(Effects of the Invention) As explained above, in the present invention, the number of data frames created on the remote channel is counted, and information on the counted number is sent to the local channel as appropriate. Since the free space in the byte count buffer of the channel can be immediately known, data transfer can be performed efficiently and quickly. - Transmission controller, 380... Pite count counter (RBCB), 390 ...Frame receiving circuit.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of a data transfer device according to the present invention, FIG. 2 is a diagram showing a data transfer request/guidance count frame, and FIG. 3 is a diagram showing a data frame.
FIG. 4 is a diagram showing a data count frame. 100...Local channel, 110...Frame receiving circuit, 120...Data frame buffer (LDB). 130... Input/output (Ilo) controller, 140° 160... Buffer controller, 150... Transmission controller, 170... Frame transmission circuit, 180
...Frame BC generation circuit, 190...Tsumite count buffer (LBCB), 300...Remote channel. 310...input/output (I/l) controller, 320
...Data buffer (RDB), 330...Frame transmission circuit.

Claims (1)

[Claims] 1. A local channel connected to an input/output processing device;
a remote channel that is connected to the local channel and performs data transfer with the device control device;
When transferring data from the remote channel to the local channel, a plurality of data transfer request byte count frames indicating a data transfer request are provided from the local channel to the remote channel, and the data transfer request byte count is stored in a storage means. , in a data transfer device that sequentially sends data frames to the local channel based on the data transfer request byte count frame, the remote channel includes a count means for counting the number of data frames, and a count value of the count means is stored in advance. When the count value reaches a predetermined value, the count value is sent to the local channel, and the local channel includes calculation means for calculating the difference between the transfer request byte count frame number and the transmitted count value. 1. A data transfer device characterized in that the storage means is managed based on the difference. 2. The data transfer device according to claim 1, wherein the sending means sends a count value to the local channel when sending of the data frame is completed. 3. The data transfer device according to claim 1, wherein the local channel determines whether to send the data transfer request byte frame based on the difference.