JPH0389743A - Terminal equipment - Google Patents

Abstract

PURPOSE:To avoid the fault of a line by informing an operator of the effect of overlap when all the equipment addresses of terminal equipments which are previously connected to the line are all fetched before the line is connected to a terminal controller and when overlap is detected. CONSTITUTION:A host connection buffer 3 connecting/disconnecting a transmission/reception buffer part 2 and a transmission/reception control part 4 is provided between the transmission/reception buffer part 2 with the terminal controller 21 and the transmission/reception control part 4. When a register dumping the use state of the line as to all the equipment addresses are compared with the equipment address which is set to its own equipment. When they are not overlapped, the buffer 3 is connected and transmission/reception with the terminal controller 21 is attained. When they are overlapped, the buffer 3 is not connected and the effect is informed to the operator so as to prompt resetting. Thus, the overlap of the equipment addresses is detected before the connection to the terminal controller 21 is executed, and a system can be restored.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a terminal device that can detect duplication of device addresses and enable resetting.

[Conventional technology]

Generally, when the data link establishment method between the terminal controller and the terminal device is the polling/selecting method, if the device addresses of the terminal devices overlap, response frames from one terminal will collide on the line, resulting in line failure. occurs.

The method for avoiding failures due to duplication of device addresses as described above is that the terminal device itself does not have a unique device address, and as shown in Japanese Patent Laid-Open No. 62-298859, the device address of the terminal device is changed when the terminal device starts up. A method is known in which settings are distributed from a terminal controller that is being managed.

[Problem to be solved by the invention]

However, this method requires the addition of a command for setting the device address, and the protocols for the terminal controller and terminal device must be set for this purpose.

An object of the present invention is to detect and recover duplicate device addresses before connecting to a terminal controller without establishing a new protocol between the terminal controller and the terminal device or installing a device for distributing addresses between the terminal controller and the terminal device. The objective is to provide a terminal device that can perform

[Means to solve the problem]

The present invention is characterized by providing an upper connection buffer between the transmission/reception buffer section and the transmission/reception control section for connecting/disconnecting the terminal controller, a register for dumping the line usage status for all device addresses, and a register for dumping the line usage status for all device addresses. If there is no overlap, the buffer is connected to enable transmission and reception with the terminal controller. Also, if one duplicate is set, the buffer is not connected and the operator is notified of this and prompted to reset.

[Effect]

As long as the device addresses overlap, the upper connection buffer disconnects the sending/receiving buffer and the sending/receiving control unit.
You can prevent it from being connected to a terminal controller.

〔Example〕

An embodiment of the invention will be described below with reference to the drawings.

Figure 1 is an internal block diagram of a terminal device that best represents the features of the present invention, Figure 2 is a time diagram for tracing the operating device address (hereinafter abbreviated as UA), and Figures 3 and 4 are The figure shows an example of a message screen to an operator and an example of its processing routine when the own UA overlaps with the UA of another operating terminal device. Note that the program shown in the processing routine is stored in the program storage section 8 in the terminal device.
The information is stored in the terminal device and processed by the CPU within the terminal device.

In FIG. 1, the terminal controller 21 (hereinafter T
CE21), a terminal device 1 comprising a data processing section 19 that processes data from the TCE21, and an upper interface section 20 that controls data transmission and reception with the TCE21.
In order to monitor all UAs for polling addresses from TCE21 and the presence or absence of responses thereto,
A unit address duplication detection section 19 is provided which is held in the state holding section 16 and notifies the data processing section 19 when a UA that overlaps with its own UA is detected.

The operation of the embodiment of the present invention configured as described above will be explained below using FIG.

First, the polling frame from the TCE 21 is received by the transmitting/receiving buffer 2, only the rear address part is taken out by the frame address detection part 13, and the terminal device address holding part 14 takes out the polling frame.
The polled U is held until the next polling occurs and is set up in the used UA state holding unit 16.
If the device assigned the A number is in the startup state, a normal response frame RR is returned from the terminal device to the TCE 21. After passing the address of the frame through the transmitting/receiving buffer 2, the frame address detecting section 13 extracts the address and T
Analyze whether it is the address of CE21 or not, and if it is the address of TCE21, write a flag indicating that the set-up address is in use from the TC:E device address detection unit 15 to the used UA status holding unit 16. Output the control signal. Similarly, for all device addresses managed by TCE21, use U
Write to the A state holding unit 16. A write time diagram is shown in FIG. 2. If no duplication of UA is detected as a result of detecting the presence or absence of a usage state, the upper connection buffer 3 is opened and the TCE 21 is brought into a connection state. If the same UA assigned to the own terminal device 1 is used by another terminal device, the device address comparison unit 17 generates an interrupt signal.

The data processing unit 19 is notified of this fact. When the interrupt signal is received, the CPU 7 in the terminal device displays on the display device 10 a message screen shown in FIG. 3 that informs the operator that the UA is duplicated and prompts the operator to reset the UA. After the display, the operator inputs an unused device address from the keyboard 12, and if the input value is valid, resets the value to the reception control unit 5 as his UA. FIG. 4 shows an example of processing when a duplication occurs, from generation of a duplication detection interrupt signal to resetting. After that, as explained above, the unit address duplication detection section 18 again performs
When it is confirmed that there is no overlap in the UA, the upper connection buffer 3 is opened under the control of the device address comparison unit 19, and the T
Connection with CE21 is established.

〔Effect of the invention〕

According to the present invention, (1) The terminal device 1 and the TCE 21 maintain a disconnected state until the upper connection buffer 3 is opened, and the condition for opening is that the device address of the device itself does not overlap with that of another terminal device. Since this is confirmed by the unit address duplication detection unit 18, line failures can be avoided.

(2) When UA duplication occurs, the usage status of other UA is displayed on the screen and the settings can be reset from the keyboard 12, making the operation easy (conversational).

(3) Since command addition with TCE21 is unnecessary,
It is compatible with TCE21 modification and existing terminal equipment.

(4) There is no need to install an address distribution device between the TCE 21 and the terminal device.

[Brief explanation of drawings]

Fig. 1 is an internal block diagram of a terminal device according to an embodiment of the present invention, Fig. 2 is a time chart for dumping device addresses, and Fig. 3 is a screen prompting the operator to reconfigure when a device address duplication is detected. Format FIG. 4 is a program flowchart for displaying FIG. 3 on the screen. 1...Terminal device, 3...Upper connection buffer, 16.
...Used UA status holding unit, 18...Unit address duplication z Ra Fujitaka 20

Claims (1)

[Claims] 1. In a terminal device that transmits and receives data frames to and from a terminal controller using a polling selection method, when the device starts operating, before connecting the terminal controller to the line, the terminal device is already connected to the line. A mechanism is provided to import all the device addresses of the device, check whether or not there are duplicates with the device address set for the device itself, and when a duplication is detected, notify the operator to that effect and prompt the device address to be reset. A terminal device characterized by: