JPH03216725A - Electronics - Google Patents

Abstract

PURPOSE:To easily and surely discriminate the state of a printer at low cost by tracing a busy signal on a printer while data is transferred and discriminating the state of the printer by means of the traced result. CONSTITUTION:An electronic unit mainbody 1 and the printer 2 are connected by respective signal lines of BUSY (busy signal), DATA (data), CLK (reference clock) and GND (reference voltage). The busy signal is traced on the printer 2 while data is transmitted, and the state of the printer 2 is checked based on the traced result. When the printer 2 is in a state where it cannot receive data, an alarm is issued. Thus, the stat where the printer cannot receive data such as the nonconnection of the printer 2 and the forgetfulness of the turning-on of a power switch in the printer 2 can surely, easily and inexpensively by checked.

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention relates to electronic devices such as word processors and personal computers, and particularly to electronic devices that are connected to a printer and send data to the printer.

[Conventional technology]

Conventionally, in the connection between a printer and an electronic device, if the BUSY signal was inactive, data was unilaterally sent from the electronic device to the printer side, and the state of the BUSY signal did not matter while data was being sent.

[Problem to be solved by the invention J However, in conventional examples such as Ouki, the BUSY signal is ignored while data is being sent, so data can be sent to the printer even when the printer is not connected or the printer's power switch is OFF (open). Therefore, with thermal transfer type handy printers, there has been a problem that data previously sent to the printer may be mistakenly printed. In view of the above-mentioned points, an object of the present invention is to reliably and easily check for inconvenient conditions in which the printer cannot receive data, such as when the printer is not connected or the printer is forgotten to turn on the power switch, even when data is being transferred to the printer. Our goal is to provide electronic devices with improved operability. L Means to solve the problem]

In order to achieve the above object, the present invention provides an electronic device connectable to a printer having a BUSY signal output, including a detection means for tracing a change in the level of the BUSY signal even while sending data to the printer, and a tracer for the detection means. The present invention is characterized by comprising a determining means for determining whether or not the printer is in a state where it cannot receive data based on the result, and a warning generating means for issuing a warning based on an affirmative determination by the determining means. . [Function] According to the present invention, in an electronic device that can be connected to a printer having a BUSY output, the BUSY output is output even when data is being sent to the printer.
The SY signal is traced, the status of the printer is checked based on the tracing results, and a warning is issued if the printer is unable to receive data, so if the printer is not connected or the printer is forgotten to turn on, It is possible to easily and inexpensively check whether a printer such as the printer cannot receive data, and the operator can receive a warning, which greatly improves operability. [Example] Hereinafter, an example of the present invention will be described in detail with reference to the drawings. Figure 1 shows the basic configuration of an embodiment of the present invention. In the figure, A is a detection means that traces changes in the level of the BUSY signal even while sending data to the printer. Reference numeral B denotes a determining means for determining whether or not the printer is in a state where it cannot receive data, based on the trace result of the detecting means A. C is a warning generating means that issues a warning based on an affirmative determination by the determining means. Figure 2 shows a connection state between an electronic device and a printer according to an embodiment of the present invention. In the figure, l is an electronic device (U) such as a word processor, and the portion to the left of the dotted line in the figure represents the main body of the electronic device. 2 is a printer (PRN) connected to the electronic device 1 via a connector, cable, or the like. FIG. 3 shows the timing of data transfer to the printer 2. As shown in FIG. 2, the electronic device main body l and the printer 2 have BUSY, DATA,
They are connected by CLK (reference clock) and GND (reference voltage) signal lines, and the direction of the signals is that the BUSY signal goes from the printer 2 to the electronic device main body 1 side, and the DATA and CLK
A signal is output from the electronic device main body l to the printer 2. GND is a reference voltage. Furthermore, the BUSY signal line is pulled up by a resistor R inside the main body. Due to this pull-up, when the printer 2 is not connected or the power switch of the printer 2 is in the F position, the BUSY signal is inactive, that is, the printer 2 appears to be in a state where it can receive data. Therefore, at this time, when the electronic device main unit 1 receives a command to send data to the printer 2 from a keyboard (not shown) or the like, it starts sending data to the printer 2 unconditionally. However, at this time, the BLISY signal of the printer 2 remains inactive during data transmission. Next, make sure that printer 2 is connected normally and
When the power switch is turned on, the BUS
The Y signal becomes active (“Low” level) for a certain period of time. In the embodiment of the present invention, by utilizing the property of this BUSY signal,
The status of the printer 2 is checked on the electronic device 1 side according to the processing procedure shown in the flowchart of FIG. First, printer 2
When the process of sending 1 byte (8 bits) of data to is selected on the electronic equipment side, the process program shown in FIG. 4 is called as a subroutine from the internal ROM. In the first step S1, the BUSY signal from the printer 2 is read, and if this BUSY signal is at "High" level (inactive), the process advances to step S4, and the BUS
If the Y signal is "Low (active)", the process moves to step S2. In step S2, it is checked whether the BUSY signal remains at the "Low" level for more than a predetermined time determined by the specifications of the printer 2. If the BUSY signal of the printer 2 is "Low" level (active) for more than a specified time, it is determined that the printer 2 is not in a state to receive data, and the process moves to step S3, where a buzzer (not shown) is activated.
A warning is issued by driving a display, etc., and the data transfer process is completed. If the time has not exceeded in step S2, the process returns to step SL again. In step S4, 1 byte (8bit) is sent to the printer 2.
t) data transfer is started, and the process moves to step S5. In step S5, the BUSY signal is constantly traced during this data transfer, and the BUSY signal goes to "High" level (
It is monitored whether there is a moment when the level changes from "inactive" to "Low" level (active). If the BUSY signal transitions from the "High" level to the "Low" level in step S5, it is determined that the data has been sent normally and the data transfer process ends. On the other hand, if the BUSY signal remains at the "High" level and does not change in step S5, the printer 2 is not connected or
Or, it is determined that the power of printer 2 is OFF,
Proceeding to step S6, a buzzer, display, etc. (not shown) is activated to issue a warning, and the data transfer is completed. FIG. 5 is a flowchart showing the processing procedure of another embodiment of the present invention. In the above-described embodiment shown in FIGS. 2 to 4, it was explained that the level change of the BUSY signal is always traced during data transfer, but when data is sent to the printer 2,
When the timing at which the USY signal becomes "Low" level (active) is known in advance, the BUSY signal may be checked only at that timing. For example, the third rising edge of the CLK (clock) signal,
This may be checked 100 μsec after the first rise of the CLK signal. The steps in the flowchart in FIG. 5 are only changes from step S5 onward in the flowchart in FIG.
Steps Sl-S4 are the same and will therefore be omitted. First, if data is sent to printer 2, step S5
-1, the BUSY signal should be at a "Low" level (active). It is determined whether it is a predetermined timing 1, and if it is the predetermined timing, the process moves to step S5-2. In step S5-2, it is determined whether or not the BUSY signal is at "Low" level (active), and if it is active, the process is terminated, and if it is not active, the process proceeds to step S6 and a warning is issued. Finish the process. [Effects of the Invention] As explained above, according to the present invention, the BUSY signal is traced even while data is being transferred to the printer, and based on the trace results, it is possible to detect conditions such as disconnection of the printer or forgetting to turn on the power switch of the printer. Since I decided to make a determination,
Since this can be easily and reliably determined at low cost and a warning is issued to the operator, the operability is significantly improved.

[Brief explanation of drawings]

Fig. 1 is a block diagram showing the basic configuration of an embodiment of the present invention, Fig. 2 is a wiring diagram showing the connection state between an electronic device main body and a printer according to an embodiment of the invention, and Fig. 3 is the same as Fig. 2. A timing chart showing an example of the timing when data is sent to a printer, FIG. 4 is a flow chart showing the processing procedure of the embodiment of the present invention shown in FIG. 2, and FIG. 5 is a processing procedure of another embodiment of the present invention. FIG. 1...Electronic device body, 2...Printer, BUSY...Busy signal from the printer (active: "Low" level) DATA...Data signal to the printer, CLK...
Reference clock from which the printer reads data, GND: Reference voltage. Figure 2 Figure 3 Figure 4

Claims (1)

[Scope of Claims] 1) In an electronic device connectable to a printer having a @BUSY@ signal output, a detection means for tracing a level change of the @BUSY@ signal even while data is being sent to the printer; The apparatus is characterized by comprising a determination means for determining whether or not the printer is in a state where it cannot receive data based on a trace result, and a warning generating means for issuing a warning based on an affirmative determination by the determination means. electronic equipment.