JPH027213B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field of the Invention The present invention provides a method for handling addresses of multiple terminal devices accessed using a polling method without duplication.
This relates to a terminal address setting method that can be set automatically.

Prior Art and Problems In a system in which data is transferred by accessing a plurality of terminal devices using a polling method, it is necessary to allocate an address unique to the terminal devices. For example, as shown in Figure 1, a plurality of terminal devices T1 to Tn are connected to a terminal control device TC via a bus BUS, and data transfer is performed by polling from the terminal control device TC, and each terminal device T1~
Tn is provided with address setting sections A1 to An. Also, KEY is the keyboard, DSP is the display device,
PRT is a printer. The terminal control device TC has a function of loading various file data of the terminal devices T1 to Tn and transferring data from each of the terminal devices T1 to Tn to a host computer (not shown).

Address setting sections A1 to An of terminal devices T1 to Tn
is usually configured with CMOS memory and backed up by a battery, and when the power is turned on, the addresses of each terminal device T1 to Tn are displayed on the display device DSP or printed by the printer PRT and sent to other terminals. This was to check whether the address was the same as the device address. If there was a duplicate, the address would be corrected using the keyboard key.

If the system configuration is not changed, the addresses set in address setting sections A1 to An will not be duplicated, but if rearrangement or expansion is performed, check again for duplicate addresses of terminal devices. There is a need. If there is a duplicate, the contents of the address setting field are changed using the keyboard key and a new address is set. As described above, in the past, addresses had to be set manually, and address duplication was detected based on display content or print results, so the address setting operation was complicated.

OBJECTS OF THE INVENTION It is an object of the present invention to automatically detect duplication of addresses of each terminal device, and to automatically set an address different from that of other terminal devices.

Structure of the Invention In the terminal address setting method of the present invention, a plurality of terminal devices are connected to a host device in a multi-drop manner via a bus including a transmission line and a reception line, and the terminal device and the plurality of terminal devices are connected to each other by a polling method. In a system for transferring data between terminal devices, a terminal device includes a switching means for switching a transmission line to a reception line, an address setting section, an address added to a response signal of another terminal device, and an address of the own terminal device. When the terminal device is in operation, the host device sends out the maximum number of polling addresses that can be connected, and the terminal device controls the response means to switch the transmission line to the receiving side and monitors the address added to the response signal of the terminal device, sets the own terminal device address different from the address of the other terminal device, and sets the own terminal device address and the address of the other terminal device by a predetermined number. The polling cycle is compared to confirm that there is no duplication of addresses, and the switching means is controlled to switch the transmission line to the transmission side to respond to the polling. An embodiment will be described in detail below. .

Embodiment of the invention FIG. 2 is an explanatory diagram of an embodiment of the invention, a
indicates a polling signal, b indicates a response signal, a polling signal with polling addresses i, i+1, i+2, ... is sent from the terminal control device, and a response signal with terminal addresses i, i+1 is sent from the terminal device. is sent. Assuming that there is no response signal to polling address i+2, a terminal device that wants to set a terminal address only needs to set i+2 as the terminal address, and it is necessary to check whether this set address i+2 is definitely not duplicated. is monitored for 2 to 3 polling cycles, and when it is confirmed that there is no overlap, the address of the own terminal device is set to i+2 and a response signal is sent to the next polling address.

If a certain terminal address, e.g., i+1, has already been set, it is compared with the address of the response signal of another terminal device in the same way as described above, and since there is a matching address, an address different from the address of the response signal, e.g., i+2, is set. After setting it to
Sends a response signal to the next polling address.

FIG. 3 is a block diagram of the main parts of the terminal device according to the embodiment of the present invention, where SL is a transmission line, RL is a reception line,
SW is a switching circuit, SWC is a switching control circuit, SLC is a transmission level conversion circuit, RLC is a reception level conversion circuit,
CTL is the control circuit, AS is the address setting section, PW is the power supply section, CR is the relay, Cr is the relay contact, S is the power switch, KEY is the keyboard, DSP is the display device, and PRT is the printer.

When the power supply section PW turns on the power switch S, the relay CR operates and the contact cr of the relay CR is activated.
is turned on, power is supplied from the power supply section PW to each section, and at the same time, a power-on signal is applied to the control device CTL. Also, the control signal PWC from the terminal control device
The power supply unit PW can be controlled on and off by the on control signal, and the relay CR operates in the same way as when the power switch S is turned on, and its contact CR turns on, and the power supply to each part is activated. Power is supplied, and at the same time, a power-on signal a is applied to the control device CTL.

The control device CTL receives the power-on signal a,
Add control signal b to switching control circuit SWC. Based on this control signal b, the switching control circuit SWC controls the switching circuit SW to connect the transmission line SL to the reception level switching circuit RLC to which the reception line RL is connected. Since each terminal device is connected to the transmission line SL and the reception line RL in a multi-drop manner, it is possible to receive a response signal sent to the transmission line SL from another terminal device.

As mentioned above, the address setting section AS is CMOS
It is composed of memory, etc., and a certain address k
is already set, the control device CTL
is compared with the terminal address added to the response signal sent by another terminal device. This operation is performed for a predetermined number of polling cycles, and if there is no duplicate address, the control device CTL sends a control signal b to the switching control circuit SWC to control the switching circuit SW,
Switch to the initial state. That is, the transmission line SL is connected to the transmission level switching circuit SLC, and the reception line RL is connected to the reception level switching circuit RLC.

Then, a response signal with the address of the own terminal device added to the next polling address is sent out, and the terminal address setting operation is completed.

Also, if no address is set in the address setting section AS, the response signals of other terminal devices are monitored for a predetermined number of polling cycles, and an unused address is set in the address setting section AS from the control device CTL. .

FIG. 4 shows a flowchart of an embodiment of the present invention, in which the switching circuit SW is controlled by powering on manually or automatically from the terminal control device, and the transmission line is
The SL is switched and connected to the receiving side, that is, the receiving level conversion circuit RLC. Next, the response signal of another terminal device is monitored, and the address added to the response signal is compared with the address of the own terminal device to identify that there is no overlap, or an address different from the address added to the response signal. is selected and monitored for 2-3 polling cycles. When it is confirmed that the monitoring periods do not overlap, the switching circuit SW is switched to the initial state and a response signal is sent to the polling address. If there are duplicates, the response signals of other terminal devices are monitored again and the above-described operations are repeated.

As mentioned above, when the power is turned on, it is detected whether the address of the own terminal device overlaps with the address of another terminal device, and if there is no overlap, it is determined that the address of the own terminal device has been set. If there is a duplicate, an address different from the address of other terminal devices will be set. Furthermore, if no address is set in the address setting section AS of the own terminal device, an address that is not used by another terminal device can be selected and set as the address of the own terminal device.

When a cash register is used as a terminal device, it is common for various file data to be downloaded from the terminal control device early in the morning of the day, and it takes a considerable amount of time to load this file data, so automatic loading is not possible. It is requested that the following be done. In such automatic loading, if there is a duplication of terminal addresses, the system may go down. However, as mentioned above, before downloading file data, it is possible to check for duplicate terminal addresses, and if there are duplicates, it can be automatically set to a different address, making automatic loading possible. . Furthermore, even when a standby terminal device is connected, its address can be automatically set without investigating the address setting status of other terminal devices.

Effects of the Invention As explained above, the present invention provides each terminal device with switching means such as a switching circuit SW for switching the transmission line SL to the receiving side, an address setting section AS, and an addition to the response signal of other terminal devices. A means such as a control device CTL is provided to compare the address of the terminal device with the address of the own terminal device, and when the terminal device is operated manually or automatically, the switching means is provided to control the transmission line SL and the receiving level conversion circuit RLC etc. switch to the receiving side of the terminal device, monitor the address added to the response signal that other terminal devices respond to polling, set an address different from this address as the address of the own terminal device, and share this set address with the other terminal device. Compare the device address with the device address for a predetermined cycle such as 2 to 3 polling cycles, confirm that there is no overlap, control the switching means, switch the transmission line SL to the transmission side such as the transmission level exchange circuit SLC, It responds to polling, automatically checks for duplicate terminal addresses, and
Moreover, it is possible to automatically set an address that does not overlap with other terminal addresses.

Therefore, it becomes easy to set addresses for various terminal devices, and even when adding terminal devices, it is possible to automatically set addresses that do not overlap easily.

[Brief explanation of drawings]

Figure 1 is a block diagram of the main parts of a system in which a terminal control device and a connected terminal device are connected via a bus.
FIG. 2 is an explanatory diagram of an embodiment of the present invention, FIG. 3 is a block diagram of a main part of a terminal device according to an embodiment of the present invention, and FIG. 4 is a flowchart of an embodiment of the present invention. TC is a terminal control device, T1 to Tn are terminal devices,
SL is the transmission line, RL is the reception line, SW is the switching circuit,
SWC is a switching control circuit, SLC is a transmission level conversion circuit, RLC is a reception level conversion circuit, CTL is a control circuit, AS is an address setting section, PW is a power supply section, CR is a relay, cr is a relay contact, S is a power switch. ,
KEY is the keyboard, DSP is the display device, and PRT is the printer.

Claims (1)

[Scope of Claims] 1. A plurality of terminal devices are connected to a host device in a multi-drop manner via a bus including a transmission line and a reception line, and data is exchanged between the host device and the plurality of terminal devices by a polling method. In the transfer system, the terminal device includes a switching means for switching the transmission line to the receiving side, an address setting section, and an address added to a response signal of another terminal device and an address of the own terminal device. when the terminal device is in operation, the host device sends out the maximum number of connectable polling addresses, and the terminal device controls the switching device to switch the transmission line to the receiving side, Monitors the address added to the response signal of another terminal device, sets a own terminal device address that is different from the address of the other terminal device, and specifies the own terminal device address and the address of the other terminal device. A terminal address setting method characterized in that the terminal address setting method comprises comparing the number of polling cycles, confirming that there is no address duplication, controlling the switching means, and switching the transmission line to the transmission line to respond to the polling.