JPH0214825B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field of the Invention The present invention relates to a communication system between child systems in a distributed system having a parent-child relationship.

Background of the Technology There is a communication system as shown in FIG. 1 consisting of systems A, B, and C. Here, system A is, for example, a display terminal, system B is a DSC (data stream compatible), and system C is a host. P is a primary station, S is a secondary station, and a session is connected between them. APP is an application session program. Of course, it is possible for system B to relay and system A to communicate with system C. In this case, the secondary station S raises the initiate self (iNiTiATE SELF), the primary station P returns a bind (BiND), and the In other words, A and B and B and C are connected and start communicating (HDLC procedure). When communication ends, the secondary station raises TERMiNATE SELF, the primary station returns unbind (UNBiND), and the connection is severed.

Prior Art and Problems By the way, a plurality of slave stations are generally connected to a master station, and in such a system, it is also necessary for the slave stations to communicate with each other. Of course, this can be done by installing transmission lines between the slave stations, but if the master station relays the communications between the slave stations, then of course there is no need to lay a transmission line, which is economical.
However, relaying between systems that have parent-child protocols is only possible if the relay station has procedures for both primary and secondary stations, and generally the master station has only the primary station P for terminals. Therefore, communication between slave stations using the master station as a relay station is difficult.

OBJECTS OF THE INVENTION The present invention seeks to solve such problems by simple means.

Structure of the Invention The present invention provides a communication system between child systems in a distributed system having a parent-child relationship in which a parent system has only a primary station and a child system has only a secondary station. When a secondary station command indicating a communication request is received from one of the slave systems, the master station returns a primary station command indicating acceptance of the request from the primary station for the slave station, and Convert the next station command to a secondary station command using the conversion function, input it to the primary station for the other slave station, and send the primary station command indicating acceptance of a request to the other slave station. The present invention is characterized in that a communication path between the child systems is established via the parent system, and this will be explained next with reference to an embodiment.

Embodiment of the Invention In FIG. 2, A and A' are child stations (child systems), C is a master station (parent system), and B is a cluster, which correspond to A, C, and B in FIG. 1, respectively. The master station C has a plurality of primary stations P, P ₁ and P ₂ , but no secondary station S, and the slave stations A and A' have only the secondary station S. In such a system, the present invention attempts to communicate between slave stations A and B (cluster B is also the same as a slave station from the perspective of the master station) via master station C. For communication, as mentioned above, the slave station raises the secondary station command initiate self, which is a communication request, and if communication is possible, the master station returns the primary station command bind indicating acceptance of the request, and the connection is established. In the present invention, a conversion device CN ₁ is provided in the master station C, and when an initiated self is sent from a slave station, for example B, it is received by the primary station P ₂ , and the master station C returns the binding to the slave station B. The converter CN ₁ converts the binding into the initiating self and sends it to the primary station P ₁
The primary station _P1 sends the bind to the slave station A. In this way, a communication path is created between B and A via C, and communication is possible. To terminate the communication, slave station B raises the terminate self flag, and master station C generates unbind in the same manner as above and returns this to slave stations A and B, severing the connection.

If communication between A and B becomes possible, communication between slave stations A and A' using Class B as a relay station becomes possible. This can be easily understood from the fact that if _C1 is left through, the configuration will be the same as in Figure 1. In Figure 2, the application program APP is prepared on the cluster side, and when the above slave station A raises the initiate self, it receives a bind from the master station C and converts the conversion device.
Convert this to the secondary station command LOGON on CN ₂ , pass it to the application program APP, and start it.
In this way, slave station A can use the application program APP. When slave station A' raises the initiate self and requests communication with an application program, the situation is similar to that shown in FIG. 1, and the communication is performed in the S, P, and APP systems without conversion.

FIG. 3 is a diagram illustrating an example of communication possible with the present invention. Domain 1 consists of host 1, CCP (communication control processor) 1, slave stations, and cluster 1.
Domain 2 consists of host 2, CCP 2, and cluster 2. In the conventional method, communication between terminals and clusters within domain 1 requires a separate transmission line l, but
If the method of the present invention is adopted, this becomes possible via the host 1. C shows the route in this case, and Fig. 4c
shows this diagrammatically. a, b, c in Figure 3,
d corresponds to b, c, and d in FIG. Figure 3a shows communication between a slave station and a master station within the same domain,
This is also possible with conventional methods. FIG. 4b shows communication between a master station and a slave station in different domains, which is also possible using the conventional method. FIG. 4d shows communication between slave stations in different domains, which is possible in the system of the present invention by performing the above conversion. In addition, in Figure 3
PLU is a master station (primary station) line unit, SLU is a slave station (secondary station) line unit, PU is a processor unit, SSCP is a session control processor, and MSNF is a multisystem networking facility.

FIG. 5 is an explanatory diagram of the system image, where a to c are relays, d to f are SLUs, and direct communication between SLUs. In a, first SLU ₁ raises the initiate self, SSCP issues CINIT (control initiate), and PLU issues BiND/SDT (bind session/start data traffic).
Transfer to SLU ₁ and SLU ₂ , and start the session.
Raise to SSCP. As a result, as shown in Figure 5b
Communication between the SLUs starts using the PLU as a relay station. At the end of the communication, as shown in Figure c, SLU ₁ raises Terminate Self, and SSCP raises C TERM.
(control terminate), unbind PLU, and output it to SLU ₁ , SLU ₂ , and
Raise the session end to SSCP. Figure 5 d~
In the example f, first SLU ₁ raises the initiation,
SSCP issues C INIT to DPLU (dummy primary logical unit), DPLU issues bind to SLU ₁ and SLU ₂ , and raises session start to SSCP. In this way, SLU mutual communication is performed as shown in FIG. In this case, the destination address remains unchanged, but the format is partially changed, such as by making the message issuer the master station. Communication ends with Terminate Self,
CTRM, unbind, performed at session end.

Effects of the Invention As explained above, according to the present invention, a master station having only a primary station can be used as a relay station to communicate between slave stations, allowing for effective use of the network, multiple parents, and various combinations between slave stations. This provides the advantage of enabling communication.

[Brief explanation of drawings]

Figure 1 is an explanatory diagram of the conventional method, Figures 2 and 3
The figure is a block diagram showing an embodiment of the present invention, and FIGS. 4 and 5 are explanatory diagrams of communication forms and procedures. In the drawing, C is a parent system, A, A', and B are child systems, P is a primary station, S is a secondary station, and CN ₁ is a conversion device.

Claims (1)

[Claims] 1 In a communication method between child systems in a distributed system with a parent-child relationship in which the parent system has only the primary station and the child system has only the secondary stations, the parent system has a function to convert primary station commands to secondary station commands. When a secondary station command indicating a communication request is received from one of the slave systems, the master station returns a primary station command indicating acceptance of the request from the primary station to the slave station, and also sends the primary station command to the Convert it to a secondary station command using the conversion function, input it to the primary station for the other slave station, and have the primary station send a primary station command indicating acceptance of the request to the other slave station via the parent system. A communication method between child systems characterized by establishing communication paths between child systems.