JPS6210457B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a command error detection method that quickly restores the original state when a failure occurs in a processing system in which a terminal device is connected to a processing device.

In a processing system where a display terminal device is connected to a processing device, if a system failure occurs and the writing is interrupted while data is being written from the center side to the terminal side, it will take a complex process to return to the state before the failure occurred. Requires processing procedures or other measures. For example, if a system failure occurs while transferring (writing) display data from the center side to a display terminal device, the transferred data is stored on the center side in order to restore the original state after the failure is removed. The disadvantage was that it required additional memory and a processing procedure for recovery.

The present invention has been made to solve the above-mentioned drawbacks, and aims to provide a command error detection method that facilitates restoration of the system to its original state after a system failure occurs.

The present invention provides a processing system in which a terminal device having a display unit and a display memory is connected to a processing device via a communication path, and a means for adding a command code related to the data to data sent from the processing device and sending the data. Then, two types of identification signals (for example, A and B) are added alternately before and after the command code and at the end of the data, and the added identification signal, command code, and data are continuously transmitted. means, a storage unit for storing a series of identification signals sent from the processing device, and means for comparing and discriminating the stored series of identification signals and issuing a control signal when a different type of identification signal is detected. and means for reading out a command code according to the control signal and displaying it on the display section, and when sending data from the processing device to the terminal device, the command code is added to the front of the data, and the command code is added before and after the command code. and the tail of the data 2
Types A and B identification signals are added alternately, for example, when the odd-numbered transmission is performed, the identification signal A is added, and when the even-numbered transmission is performed, the identification signal B is added, and the signal is received by the sending terminal device. This command error detection method is characterized in that a series of identification signals are discriminated, and when a different type of identification signal is detected between the identification signals, a command code in the storage section is read out and displayed on the display section.

Hereinafter, the present invention will be explained with reference to the drawings. FIG. 1 is a block diagram illustrating one embodiment of the present invention, in which 1 is a terminal device, 2 is a discrimination circuit, 3 is a display section, 4 is a keyboard, 5 is a writing circuit, 6 is a storage section, 7, 8
is a readout circuit, 9 is a gate circuit, 10 is an OR circuit,
11 is a multi-control device, 12 is a memory, 13 is a communication path, 14 is a detection circuit, 15, 16, 17, 1
8, 19, 20, 21, 22 are registers, 23 is a main storage device, 24 is a file device, 25 is a processing device, A ₁ , A ₂ , A ₃ , B ₁ , B ₂ , B ₃ is an identification signal, D is data, K is a scanning circuit, L ₁ , L ₂ , L ₃ is a switching circuit, S is a command code, a, b are contacts, C, d are control signals, e, g, i are signal parts, f is a command The part and h are the data part, and the parts A, B, C, D, and H are contact points. Registers 15, 16, 18, 19 in FIG.
21 and 22 are identification signals A ₁ , A ₂ , and
It is assumed that A ₃ , B ₁ , B ₂ , and B ₃ are set in advance, and that switching circuits L ₁ , L ₂ , and L ₃ are initially set to the contact a side. Further, command codes S ₁ -Sn in the main memory 23 are sequentially read out and set in the register 17, while data D ₁ -Dn in the file device 24 are read out in the register 20 (main memory 23 is read out and set). (via).
In FIG. 1, the command code S ₁ is stored in the register 17.
is set and data _D1 is set in the register 20, the scanning circuit sequentially scans contacts A to E and starts transmission. Therefore, identification signal A ₁ , command code S ₁ , identification signal A ₂ , data
Transmission data consisting of D ₁ and identification signal A ₃ is sent to the communication path 13 in this order. When the detection circuit 14 detects the final identification signal A ₃ or B ₃ , it issues a control signal C to switch the switching circuits L ₁ , L ₂ , and L ₃ to the contact b side. Therefore, the switching circuits L ₁ , L ₂ , and L ₃ are alternately switched each time one group of transmission data is sent out. The transmitted transmission data is stored in the memory 12 of the multi-control device 11 and then transmitted to the terminal device 1 from which it is read out again. Although a plurality of terminal devices 1 are connected to the multi-control device 11, only one terminal device is shown in the figure.

In the terminal device 1, the transmitted data passes through the write circuit 5 and is stored in the storage section 6. The identification signal A ₁ is stored in the signal section e in the storage section 6.
Command code S ₁ in command part f, identification signal in signal part g
A ₂ , data D ₁ is stored in the data section h, and identification signal A ₃ is stored in the signal section i. The data _D1 of the data section h is read out by the readout circuit 8,
The data is sent to the display section 10 via the gate circuit 9 and the OR circuit 10, so that the data _D1 is displayed.

Next, in the processing device 25, the next command code S ₂ is stored in the register 17, and the data is stored in the register 20.
When _D2 is set, the scanning circuit sequentially scans contacts A to E and begins transmission. Therefore, this time, the identification signal B ₁ , the command code S ₂ , and the identification signal
Transmission data is sent out to the communication channel 13 in the order of B ₂ , data D ₂ , and identification signal B ₃ . In the terminal device 1, the transmission data is written into the storage section 6, and its contents are rewritten.

Error detection in the terminal device 1 will be explained using diagrams. FIG. 2 is a block diagram explaining error detection, where A ₁ , A ₂ , A ₃ , B ₁ are identification signals, D ₁ , D ₂ are data, S ₁ , S ₂ are command codes, e, g, i is a signal part, f is a command part, h is a data part, t is time, and _t1 is time. FIG. 2a shows transmission data that is first transmitted, and this transmission data is stored in the storage section 6 of the terminal device 1 as shown in FIG. 2b. Of these, the data _D1 of the data section h is displayed on the display section 10 as described above. Note that the command code _S1 includes the command content regarding the data _D1 . Next, the second transmission data (i.e.
B ₁ , S ₂ , B ₂ , D ₂ , B ₃ ) is transmitted, and when a system failure occurs at time t ₁ during this transmission, as shown in FIG.
Transmission data is interrupted as shown in . In this case, the contents of the storage section 6 on the terminal device side will be as shown in FIG. 2d. In FIGS. 2C and 2d, before time t ₁ of failure occurrence, signal section e of storage section 6 changes from A ₁ to
The command part f has been rewritten from _{S 1 to} S ₂ , and the signal part g has also been rewritten from A ₂ to B ₂ . However, the data section h and signal section i are not rewritten, and the previous data _D1 and identification signal _A3 remain.

The determination circuit 2 in the terminal device 1 shown in FIG.
Since it has the function of checking g and i, it issues a control signal d in the state shown in FIG. 2d. Therefore, the gate circuit 9 becomes "open" and the command code _S2 read out by the readout circuit 7 is displayed on the display section 3. The operator uses this command code S ₂ and data
By looking at the display "D _1" , you can know whether there is an abnormality or not, and you can also know up to which point it is accurate, so you can send the required request signal from the keyboard 4 to the center side when the fault is removed and the system returns to normal. This allows you to request the transmission of necessary data. Furthermore, since unnecessary data _D2 is not displayed when a failure occurs, there is no risk of confusing the operator.

As described above, in the present invention, when a failure occurs, the details of the failure can be ascertained on the terminal device side, so that the system can be quickly restarted when normality is restored, and the burden on the processing device side is reduced, resulting in cost reduction. It has the advantage of being measurable.

[Brief explanation of the drawing]

FIG. 1 is a block diagram for explaining one embodiment of the present invention, and FIG. 2 is a block diagram for explaining error detection. The symbols used in the figures are as follows. 1 is a terminal device, 2 is a discrimination circuit, 3 is a display unit, 4 is a keyboard, 5 is a write circuit, 6 is a storage unit, 7 and 8 are read circuits, 9 is a gate circuit, 10 is an OR circuit, 11 is a multi a control device, 12 a memory, 13 a communication path,
14 is a detection circuit, 15, 16, 17, 18, 1
9, 20, 21, 22 are registers, 23 is a main storage device, 24 is a file device, 25 is a processing device,
A ₁ , A ₂ , A ₃ , B ₁ , B ₂ , B ₃ are identification signals, D, D ₁ ,
_D2 is data, K is a scanning circuit, _L1 , _L2 , _L3 are switching circuits, S, _S1 , _S2 are command codes, a, b are contacts,
C, d are control signals, e, g, i are signal parts, f is command part, h is data part, t is time, _t1 is time, i,
B, H, D, and H indicate contact points.

Claims (1)

[Claims] 1. In a processing system in which a terminal device having a display section and a display memory is connected to a processing device and data transferred from the processing device is displayed on the display section, a command code related to the data is added to the data sent from the processing device. means for adding a plurality of types of identification signals to the front and rear of the command code and the tail of the data for each transmission and transmitting the data as a series of data; a storage section for storing an identification signal and a command code; a means for comparing and discriminating the identification signals in the storage section and emitting a control signal when a different type of identification signal is detected; and a means for generating a command code in the storage section by the control signal. means for displaying on the display section, the command code is added to the front part of the data when the data is sent from the processing device to the terminal device, and the command code is added to the front part of the data and the end part of the data is An error detection method characterized in that the terminal device adds a different type of identification signal for each transmission and sends it out, and the terminal device detects an error by detecting a mismatch between the identification signals read from a storage unit. .