JPH0748757B2 - Communication device - Google Patents

Description

The present invention relates to a communication device in which a terminal device such as a so-called handheld computer, pocket computer or handy terminal is connected to a higher model through a communication adapter. The present invention relates to a communication device including a communication adapter for deriving a continuous activation signal to a terminal in response to a pulsed activation command signal from a host model, and a connection unit for connecting the terminal to the communication adapter.

[Prior Art] A communication device of this type generally known in the past is an example of the connection means for connecting a communication adapter to a higher-order model such as a workstation by a connector or the like. It was configured by connecting terminals with a connector or the like. Then, when a pulsed start command signal from the higher model is input to the communication adapter, a continuous start signal is derived from the communication adapter to the terminal side, which allows the terminal to select from the next higher model. Prepare to receive signals.

[Problems to be Solved by the Invention] However, in this type of conventional communication device, the operator mistakenly disconnects the terminal from the communication adapter during communication when a start signal is output from the communication adapter to the terminal, and then again. When the terminal is plugged in and unplugged, the startup signal for the terminal repeats ON and OFF, which results in the terminal malfunctioning and destroying the programs and data stored inside. There was a flaw.

In view of such circumstances, the present invention, even if the terminal is removed from the communication adapter during communication when the activation signal is output from the communication adapter to the terminal side, the activation signal for the terminal repeats ON and OFF. It is an object of the present invention to provide a communication device capable of preventing the above.

[Means for Solving the Problems] A communication device according to the present invention includes a communication adapter for deriving a continuous activation signal to a terminal in response to a pulsed activation command signal from a host model, and the terminal for communicating with the communication device. The communication adapter includes connection means for connecting to the adapter, and connection state detection means for detecting a connection state by the connection means, wherein the communication adapter detects the detection output from the connection state detection means. It is characterized in that it has a standby means for waiting the output of the activation signal to the connected terminal until the activation signal is issued from the higher-level model and the activation signal output condition is satisfied after the derivation of the above.

[Operation] According to the present invention, the connection state by the connection means for connecting the terminal to the communication adapter is detected by the connection state detection means. Then, when the detection output from the connection state detection means is derived, the connected terminal device until the activation signal output condition is satisfied from the host model after the detection output is derived and the activation signal output condition is satisfied. The communication adapter is provided with standby means for waiting for the output of the activation signal to the communication adapter. As a result, even if the terminal is connected to the communication adapter during communication, the previous start signal will not be input into the terminal at the same time as the connection, and wait for the start command signal issued from the higher model after connection. For the first time, the activation signal will be input to the terminal.

Embodiments of the Invention Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 2 is a block diagram showing the entire communication device according to the present invention.

A communication adapter 4 is connected to a workstation 2 which is an example of a higher-end model.
A terminal 6 such as a so-called handheld computer, pocket computer or handy terminal is connected. Further, as shown by the arrow in FIG. 2, the terminal device 6 is inserted into one of the plurality of slots (grooves) formed in the communication adapter 4. In this state, a command signal from the workstation 2 is input to the terminal device 6 via the communication adapter 4, and the terminal device 6 operates based on the input command signal.

FIG. 3 is a system diagram of the communication adapter 4.

The communication adapter 4 has a CPU 18 that can execute control operations in a predetermined procedure, a ROM 14 that stores operation program data of the CPU 18, a RAM 16 that can write and read necessary data, and serial-parallel conversion and control. It is composed of a serial input / output controller 20 and the like. The CPU 18 is equipped with an I / O port for maintaining signal consistency with an external device.

The communication adapter 4 is configured to be connectable to the work station 2 which is an example of a higher model by a connector 10. Further, each of the terminals 6a to 6f is configured to be connectable by the connectors 12a to 12f which are an example of connecting means. FIG. 3 shows six types of terminals, that is, the terminal 6a in the slot 1 to the terminal 6f in the slot 6, each terminal comprising a start signal control circuit 30 and an optical communication circuit 32. There is. In the figure, 8a to 8f are status display lamp control circuits for displaying the control status of each terminal. In the figure, reference numeral 50 is a standby means described later.

A predetermined power source is supplied to each of the circuits, the CPU 18, the RAM 16 and the like from a power source circuit (not shown).

FIG. 4 is a flowchart showing a program stored in the ROM 14 shown in FIG.

First, in step S1, it is determined whether or not there is a terminal in the slot designated by the host model. If it is determined that there is no terminal, the program ends. If it is determined that there is a terminal device, the process proceeds to step S2, and similarly to step S1, it is determined whether or not the terminal device is in the slot designated by the host model, and it is determined that there is no terminal device. In that case, the program ends as it is. Then, when it is determined in step S2 that there is a terminal, the process proceeds to step S3 for the first time. Thus, step S1
Then, in step S2, two checks are performed to control the existence of the terminal device. next,
In step S3, it is determined whether or not a start command signal is transmitted from the higher-level model. If it is determined that it is not, the program ends as it is, but if it is determined that there is, the process proceeds to step S4. In step S4, processing for outputting a terminal activation signal generation pulse signal from the I / O port is performed, and then the program ends.

FIG. 1 is a circuit diagram showing a specific configuration of the standby means 50 shown in FIG.

The standby means 50 is a D-type flip-flop 24 and an LE for optical communication.
It is composed of a D driver 26. Further, in the figure, reference numeral 28 denotes a switch, which is built in the connectors 12a to 12f and turned on when the terminal is connected, and turned off when the terminal is disconnected. The switch 28 constitutes connection state detection means for detecting the connection state of the connection means for connecting the terminal to the communication adapter.

First, if the terminal is connected to the communication adapter via the connector, the switch 28 is turned on and the voltage is flip-flop.
It is input to the 24 ▲ ▼ terminals and also to the CPU as a terminal presence / absence confirmation signal. Then, the CPU can confirm that the terminal exists, while the flip-flop 24
Clearing is canceled by. In this state, when the start command signal is issued from the host model and input to the CPU of the communication adapter, the CPU of the communication adapter outputs the start signal ON signal for one pulse and is input to the CK terminal of the flip-flop 24. As a result, the output from the Q terminal of the flip-flop 24 is switched from the low level to the high level,
It is inverted by the optical communication LED driver 26 and becomes a low level. Then, a current starts to flow through the light emitting diode 30, a predetermined light is emitted from the light emitting diode 30, and the light is input to the terminal as an activation signal.

In the above-mentioned state, the terminal is in a normal communication state in which it operates based on the command signal from the host model, but a case where the terminal is unexpectedly pulled out during the communication will be described.

When the terminal is unplugged from the communication adapter, first switch 28
Is turned off, the flip-flop 24 is cleared, and the terminal presence / absence confirmation signal is not input to the CPU. As a result, the output from the Q terminal of the flip-flop 24 is switched to the low level, is inverted by the optical communication LED driver 26 and becomes the high level, and the current stops flowing through the light emitting diode 30 and the start signal is not output. Further, since the terminal presence / absence confirmation signal is not input to the CPU, NO is determined in steps S1 and S2 as shown in FIG. 4, so the activation signal ON signal from the CPU is input to the flip-flop. Will not be done.

Next, when the terminal is further connected to the communication adapter in this state, first, the switch 28 is turned on, the clear of the flip-flop 24 is released, and the terminal presence / absence confirmation signal is input to the CPU. Then, YES is determined in steps S1 and S2 in FIG. In this state, the output from the Q terminal is still at the low level because the clear of the flip-flop 24 is released. Therefore, at this stage, the activation signal is not yet output from the light emitting diode 30. Next, when a startup command signal is issued from the host model and input to the CPU of the communication adapter, YES is determined in step S3 of FIG. 4, and the startup signal ON signal is input from the CPU to the CK terminal of the flip-flop. It Then, the output from the Q terminal of the flip-flop 24 is switched to the high level, is inverted by the optical communication LED driver 26 and becomes the low level, and the current flows through the light emitting diode 30 to output the activation signal. In other words, if the terminal is pulled out and reconnected during communication, the activation signal is output to the terminal only after the activation command signal issued from the higher-level model is derived after the connection. Become. That is, by the flip-flop 24 and the LED driver 26 for optical communication, in response to the detection output from the connection state detection means, when the terminal is connected, the start command issued from the host model after the connection A standby unit is configured to wait for the input of the activation signal of the connected terminal until the activation signal is derived based on the signal.

[Effects of the Invention] Even if the terminal is connected to the communication adapter during communication, the previous activation signal is not input into the terminal at the same time as the connection, and the activation command signal issued from the higher model after the connection is transmitted. Since the start signal will be input to the terminal only after waiting, the operator mistakenly disconnects the terminal from the communication adapter and plugs it in again during communication when the start signal is output from the communication adapter to the terminal side. Even if the device is connected or disconnected, the start signal for the terminal does not repeat ON and OFF, avoiding the inconvenience that the terminal malfunctions and the programs and data stored inside are destroyed. I got it. In addition, the communication adapter is provided with a standby function that waits for a start command signal issued from a higher-level model after the terminal is connected to the communication adapter and outputs a start signal to the terminal for the first time. For this reason, the higher-order model need not have the standby function at all, and the standby function can be exhibited without giving a special burden to the higher-order model.

[Brief description of drawings]

FIG. 1 is a circuit diagram showing a standby means used in the present invention. FIG. 2 is a schematic diagram showing the overall configuration of the communication device according to the present invention. FIG. 3 is a system diagram of a communication adapter used in the present invention. FIG. 4 is a flow chart for explaining the operation of the communication adapter. In the figure, 2 is a workstation, which is an example of a high-end model,
6a to 6f are terminals, 4 is a communication adapter, 12a to 12f are connectors as an example of connection means, 28 is a switch as an example of connection state detection means, 50 is a standby means, 24 is a flip-flop, and 26 is optical communication. LED driver for.

Claims (1)

[Claims] 1. A communication adapter for deriving a continuous activation signal to a terminal in response to a pulsed activation command signal from a host model, and connection means for connecting the terminal to the communication adapter. Connection state detecting means for detecting a connection state by the connecting means, wherein, when the detection output from the connection state detecting means is derived, the communication adapter is activated from a higher-level model after the detection output is derived. A communication device, comprising: standby means for waiting the output of the activation signal to the connected terminal until a command signal is issued and the activation signal output condition is satisfied.