JPS622345B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a data transmission system, and more particularly to a control method between a data processing device and a communication control device in a slave side system of a data communication system.

In general, a data communication system using a polling/selecting connection method is comprised of a slave station (terminal) which is a source of information, and a center which processes information and controls connections.

To explain using the configuration example shown in Fig. 1, the center side 2
consists of a processing device 5, a communication control device 6, and a modem 7, and the slave station side 3 or 4 consists of a terminal device 10, a modem 8, or a processing device 12, a communication control device 11, and a modem 9.

The center side and the slave station side are connected by a line 1. According to this figure, multiple connections are made on the slave station side using a branching device. In the system configuration described above, the center side transmits a polling activation signal or a selecting activation signal in order to check the status of the slave station side. When the slave station receives an activation signal addressed to itself, it must send some kind of response to the received signal. If the received signal is a polling activation signal, if there is transmission data, that data is transmitted; if there is no transmission data, a response with no data is transmitted. Furthermore, if the received signal is a selection start signal, a response must be sent to determine whether data can be received from the center side.

As described above, in a data transmission system having a polling signal/selecting signal, a data processing system having a host data processing device and a communication control device on the slave station side may be used.

In the above case, conventionally, the host data processing device 12 issues a reception command to the communication control device 11 in the slave station system as shown in FIG. When the communication control device 11 receives a polling signal/selecting signal from the center system, it transfers it to the host data processing device 12 and generates an interrupt. In response to this interrupt, the host data processing device 12 determines whether the received signal is a polling signal or a selecting signal. In the case of a selecting signal, further processing is performed to determine whether or not data can be received from the center system, but detailed explanation will be omitted.

In the case of a polling signal, it is determined whether or not there is data to be transmitted to the center system. If transmission data exists, the transmission data is transmitted to the center system via the communication control device 11.

If it does not have data to send, it must send a response character to the center system indicating that it does not have data to send. Therefore, the host data processing device 12 creates a response character and issues a transmission command to the communication control device 11. The communication control device 11 transfers a response character to the transmission command and sends it to the center system, and after the transmission is completed, the host data processing device 12
causes an interrupt to. In response to this interrupt, the host data processing device 12 sends the receive command again to the communication control device 1.
Start at 1. Therefore, considering the time when the polling signal is received, even if there is no data to be sent to the center system, an interrupt will be generated to the host data processing device 12, which causes the host data processing device 12 to send The commands and re-received commands must be issued, increasing the load on the host data processing device 12.

The present invention aims to solve the above points. Therefore, the present invention provides a slave station system that is connected to a center system via a communication line and that transfers data to and from the center system in response to an activation signal including a polling signal from the center system. In a data transmission system in which at least one of the child station side systems includes a data processing system having a communication control device and a host data processing device, the host data processing device receives the polling signal. At this time, prepare a transmission command for transmitting a predetermined response character indicating that there is no transmission data, a reception command for receiving an activation signal including the polling signal, and an intra-channel skip command, The above-mentioned commands are stored in a command storage means so as to be chained to the above-mentioned transmission command, the above-mentioned reception command to the above-mentioned intra-channel jump command, and the above-mentioned intra-channel jump command to the above-mentioned transmission command, and the transmission When data is generated, the above-mentioned intra-channel jump command is converted into a no-operation command, the command chain is stopped, and an interrupt from the above-mentioned communication control device is generated. is configured to initiate a received command, and when the communication control device receives the polling signal from the center system in response to the received command, it transmits status information that allows the command chain to continue to the host data processing device. and when a selecting signal is received from the center system, status information for canceling the command chain is notified to the host data processing device.

Hereinafter, the present invention will be explained with reference to the drawings. FIG. 3 is a block diagram of a slave station data processing system according to an embodiment of the present invention. In FIG. 3, 11 is a communication control device, 12 is a host data processing device, 1
3 is a command storage section, 14 is a processing section, 15 is a data storage section, 16 is a channel section, 17 is a processing section, and 18 is a line correspondence section. Further, FIG. 4 shows the operation of the embodiment of FIG. 3 in an operational flow diagram.

Hereinafter, the operation of the embodiment will be explained based on FIG. 4.

The host data processing device 12 has a command storage unit 13
A transmitting CCW (CHANNEL COMMAND WORD) having a transmitting command to transmit a response character in advance is configured to be chained to the next receiving CCW having a receiving command to receive a polling signal/selecting signal, and furthermore, the receiving CCW is , send CCW above
The next command with a TRANSFER IN CHANNEL that specifies
A CCW group configured to chain commands to the TIC CCW will be provided. The host data processing device 12 then
When the communication control device 11 is activated, it is determined whether there is data to be sent to the center system. If there is no transmission data, the received CCW is designated as the command address and the communication control device 11 is activated. Also,
If there is transmission data, the command storage unit 13
No Operation Order (NOP) for TIC CCW
Replace it with and start it. Communication control device 11
monitors the activation signal from the center system while the transmission/reception command is being executed. If the received activation signal is a selecting signal, it notifies the channel unit 16 of the status (channel end, input/output device end, device exception) with device exception information added to prevent the command chain, and ends the execution of the received command. . A series of command chains is inhibited by the above status, and an interrupt is generated to the host data processing device 12. Further, if the received activation signal is a polling signal, the normal status (channel end, input/output device end) is notified to the channel unit 16. Based on the above status, the chain of command will continue and the next CCW will be executed.
Here, if the CCW following the reception CCW is the TIC CCW, the transmission CCW will be executed next. send
In CCW, a response character is sent to the center system. Since the transmission CCW is command chained to the reception CCW, after the transmission is completed, the activation signal from the center system is monitored again by the reception command of the reception CCW. In addition, when transmission data to the center system is generated in the host data processing device 12, the TIC CCW of the command storage unit 13 is
By replacing it with a NOP command, the command chain is suppressed and an interrupt occurs, so there is no need to reissue the transmission command.

As described above, according to the present invention, when data is transferred or created to the center system, the host data control device rewrites the contents of the command area, thereby eliminating the need to restart the sending and receiving commands. The load of command issuance and interrupt processing can be reduced, and the processing capacity and processing efficiency of the host data processing device can be improved.

[Brief explanation of the drawing]

FIG. 1 is a configuration example of a data communication system, FIG. 2 is a conventional operation flow in a slave station system, FIG. 3 is a block diagram of a slave station data processing system according to an embodiment of the present invention, and FIG. 4 is an implementation example. FIG. 3 is an example operational flow diagram. In FIG. 3, 11 is a communication control device, 12 is a host data processing device, 13 is a command storage unit, and 14 is a communication control device.
15 is a processing section, 15 is a data storage section, 16 is a channel section, 17 is a processing section, and 18 is a line correspondence section.

Claims (1)

[Claims] 1. A slave station system that is connected to a center system via a communication line and transfers data to and from the center system in response to an activation signal including a polling signal from the center system, In a data transmission system in which at least one of the child station side systems is constituted by a data processing system having a communication control device and a host data processing device, the host data processing device receives the polling signal when receiving the polling signal. , a transmission command for transmitting a predetermined response character indicating that there is no transmission data, and a reception command for receiving an activation signal including the polling signal;
Prepare an intra-channel jump command, and send each of the above commands so that the above-mentioned transmission command is chained to the above-mentioned reception command, the above-mentioned reception command is chained to the above-mentioned channel jump-over command, and the above-mentioned intra-channel jump command is chained to the above-mentioned transmission command. is stored in the command storage means, and when transmission data is generated, the intra-channel jump command is converted into a no-operation command, the command chain is stopped, and an interrupt from the communication control device is generated. The first activation of the communication control device is configured to issue a reception command, and when the communication control device receives the polling signal from the center system in response to the reception command, the communication control device is in a state where it can continue the command chain. Information is notified to the host data processing device, and when a selecting signal is received from the center system, status information for canceling the command chain is notified to the host data processing device. data transmission system.