JPH025246B2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to a data recording device that measures and records consumption data of electricity, gas, water, etc. at fixed time intervals, and later collects and analyzes the data. The present invention relates to a data recording device having a removable memory cartridge.

[Technical background of the invention]

FIG. 1 is a block diagram showing the schematic structure of a conventional data recording device. To explain the configuration for measuring power usage data, there is a conversion circuit 1 that converts power into the number of pulses, and a conversion circuit 1 that counts the number of output pulses of the conversion circuit 1 and outputs the contents of the counter at fixed time intervals and then clears the counter. counter circuit 2
and a memory cartridge 7 which can be removed from the main body of the device to store the measured value of the counter circuit 2 and collect the data, and to control writing of data to the memory cartridge 7, clearing of the counter circuit, etc. It is composed of a control circuit 3, and interface circuits 41 and 42 for exchanging signals between the main body of the apparatus and the memory cartridge 7.

Built into the memory cartridge 7 are a memory 5 for storing measured values, a clock 6 for notifying the control circuit 3 of a fixed time period, and a data input/output interface 42. The memory cartridge 7 can be attached to and detached from the main body of the apparatus, and the switch 8 is used to detect whether the memory cartridge is attached or detached.

That is, when the memory cartridge 7 is attached to the main body of the apparatus, the switch 8 is closed and the control circuit 3 detects that the memory cartridge 7 is attached. Data is exchanged between the control circuit 3 and the memory 5 in the memory cartridge 7.
This is performed only when the switch 8 is closed.

[Problems with background technology]

In a data recording device having such a configuration (hereinafter referred to as a load survey device), when the contents of the counter 2 are being written to the memory 5 in the memory cartridge 7 via the interfaces 41 and 42, the memory cartridge 7 is If removed from the main body of the device, it has drawbacks such as the possibility that data may be lost or other data may be destroyed due to failure to operate normally.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide a data recording device that controls the sequence of writing data to a memory in a memory cartridge to prevent data loss or malfunction.

[Summary of the invention]

In order to achieve the above object, the present invention includes a recording device main body, a memory cartridge detachably attached to the recording device main body, and measurement data for each fixed time period via an interface within the recording device main body. A data recording device comprising a control means for storing data in a memory in a memory cartridge,
The first part opens and closes when the memory cartridge is inserted or removed.
a second switch that opens and closes in response to locking and unlocking of the memory cartridge, and inputs opening/closing signals of the first and second switches to indicate the installation state between the recording device main body and the memory cartridge. A detection circuit for outputting a signal is provided, and the control means controls conduction/non-conduction of the interface based on the signal representing the attachment state.

[Embodiments of the invention]

Embodiments of the present invention will be described in detail below with reference to the drawings. Note that the same parts as shown in FIG. 1 are denoted by the same reference numerals, and the explanation thereof will be omitted.

FIG. 2 is a block diagram showing an embodiment of the present invention, and shows a configuration for measuring power usage data as in the case of FIG. 1. Load voltage V _L
and the load current _IL are input to the conversion circuit 1. The conversion circuit 1 includes, for example, a multiplier that multiplies the load voltage V _L and the load current I _L , and a W/F converter (Watt/
frequency conversion) and a frequency divider that converts the output of the W/F converter into an appropriate ratio.
The output of the conversion circuit 1 is transferred to the control circuit 3 via the counter 2 at regular intervals. The control circuit 3 sends the contents of the counter 2 to input/output interfaces 42 and 43.
is input into the memory 5 via the . The memory cartridge 7 includes an interface 42, a memory 5, and a clock 6, and is removable from the main body of the road survey apparatus. The attachment/detachment state of the memory cartridge 7 is detected by two switches SW ₁ and SW ₂ and a detection circuit 9 connected thereto. Detection circuit 9 receives signals from switches SW ₁ and SW ₂ and control circuit 3
A signal indicating the installation state between the recording device main body and the memory cartridge 7 in response to the RST signal from the
Q ₁ , Q ₂ , Q ₃ are output, thereby controlling the control circuit 3.
and the operation of the interface 43 is controlled.

Figure 3 shows the detection circuit 9 and interface circuit 4.
3 is a circuit diagram showing an example of the configuration of No. 3; FIG. switch
SW ₁ is a cartridge detection switch that detects the connection of the cartridge 7 to the main body, and opens and closes according to the attachment and detachment of the cartridge 7. Further, the switch SW ₂ is a lock switch that is manually operated after the cartridge is inserted, and is a switch that opens and closes in response to the locking/unlocking of the memory cartridge 7. The opening/closing signal of the switch SW ₁ is inputted to the set side of the RS flip-flop 12 and the D terminal of the D flip-flop 13 via the inverter gate 10. The opening/closing signal of switch SW ₂ is input to the clock terminal of D flip-flop 13 via inverter gate 11, and at the same time is input to the clock terminal of D flip-flop 14 via inverter gate 11 and inverter gate 15. Here, it is assumed that switches SW ₁ and SW ₂ are closed when the cartridge 7 is installed and locked.

The output Q ₁ of the RS flip-flop 12, the output Q ₂ of the D flip-flop 13, and the output Q ₃ of the D flip-flop 14 are input to the control circuit 3, respectively. The output Q ₂ is also used as a control signal for the tristate gates 16 ₁ to 16 _o of the interface circuit 43. The output signal _Q3 of D flip-flop 14 forms the unlock signal.
Further, the RST signal from the control circuit 3 is input to the reset terminals of the flip-flops 12, 13, and 14. The control circuit 3 (not shown) is composed of a microprocessor and a ROM containing a program, and a memory 5 in the memory cartridge 7.
consists of an address selector circuit and an IC memory circuit. Note that the memory cartridge 7 has a built-in battery (not shown), and the contents of the memory 5 and clock 6 will not change or stop operating even if the memory cartridge 7 is separated from the main body.

The memory cartridge 7 has a structure that allows it to be separated from the main body of the load survey device when collecting data. When the memory cartridge 7 is installed, the clock 6 outputs a signal to the control circuit 3 via the interface circuits 42 and 43 at certain time intervals. At this time, the control circuit 3 reads the contents of the counter 2 and stores the data in the memory 5.
and clear counter 2.

Next, the operation when attaching and detaching the memory cartridge 7 will be explained using the timing chart shown in FIG. The switch _SW1 is a microswitch that detects the insertion of a cartridge. When the cartridge is inserted, the switch is automatically closed and the output _Q1 of the flip-flop 12 becomes "1". In this state, since the gates 16 ₁ to 16 _o of the interface circuit 43 are in a high impedance state, signals cannot be exchanged between the memory cartridge 7 and the control circuit 3.

Switch SW ₂ is then locked by the operator's hand. At this time, the D input of flip-flop 13 has already been set to "1" by switch SW ₁ , so when switch SW ₂ is closed, its output
Q ₂ becomes “1”. The output Q ₂ is used as a control signal for the tri-state gate 16, and since the gate 16 becomes conductive, the control circuit 3
It becomes possible to send and receive signals between the memory cartridge 7 and the memory cartridge 7. That is, after the switch SW ₂ is closed, the control circuit 3 can perform the data recording operation. Conversely, when removing memory cartridge 7, first press lock/unlock switch SW _2.
opens. At this time, the output of the gate 15 changes from "0" to "1". and flipflop 1
Since the D input of 4 is “1” (=Q ₁ ), the output Q ₃
becomes “1”. That is, flip-flop 14
The output Q ₃ of the lock/unlock switch SW ₂
detects that the circuit is open and notifies the control circuit 3 of this. At this time, the control circuit 3 writes the contents of the counter (DATA1 in FIG. 5), the end time, and the end mark into the memory 5, as shown in FIG.

Furthermore, after the writing is completed, the control circuit 3 generates the RST signal and flips the flip-flops 12, 13, 1.
Reset 4. After reset, output 12 is “0”
Gate 1 of the interface circuit 43
6 becomes high impedance, and transmission and reception of signals between the control circuit 3 and the memory cartridge 7 becomes impossible.

Subsequently, since the memory cartridge 7 is removed, the switch _SW1 is opened. Lock switch SW ₂
The operation to release the memory cartridge 7 and remove it is done manually, so the
It takes 200ms. On the other hand, the time for Q ₃ = 1 (writing operation at the end) is around 10 ms at most, so switch SW ₁ is opened after switch SW ₂ is opened.
Writing can be performed until the circuit is opened.

〔Effect of the invention〕

As explained above, in the present invention, the gate of the interface circuit is opened and closed based on the opening/closing signals generated from the switch that opens and closes the gate in response to the insertion and removal of the memory cartridge, and the switch that opens and closes the gate in response to the locking and unlocking of the memory cartridge. Control using the generated signals makes it possible to prevent bus signal instability and malfunctions caused by cartridge attachment/detachment. In addition, there is a time delay between opening and closing the switch, and this time delay can be used to write the final data (DATA1), end time, and end mark into the memory just before the cartridge is removed. Therefore, the next time a new memory cartridge is inserted and data is recorded and retrieved, there will be no time gaps or data discontinuities, improving the reliability of the data. Additionally, end marks are written in memory to delimit data. That is, if the memory cartridge has a large capacity, even if the memory cartridge is attached to another load survey device and continuous recording is performed, the end mark makes the unit of recording clear.

Furthermore, in the present invention, since the memory cartridge is not removed during the write operation, there is no need to worry about data being lost or erroneous data being written. Accurate data collection is therefore possible. The present invention can be applied not only to road survey devices but also to other data recording devices to which a memory cartridge can be removably attached, and similar effects can be obtained.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an example of a conventional data recording device, FIG. 2 is a block diagram showing the configuration of an embodiment of the present invention, and FIG. 3 is a specific circuit of the detection circuit and interface used in the present invention. FIG. 4 is a timing chart for explaining the operation of the circuit shown in FIG. 3, and FIG. 5 is a diagram showing the contents stored in the memory in the memory cartridge. 3...Control circuit, 5...Memory, 6...Clock,
7...Memory cartridge, 9...Detection circuit, 4
2,43...Interface circuit, _SW1 ...Attachment/disconnection detection switch, _SW2 ...Lock/unlock switch.

Claims (1)

[Scope of Claims] 1. A recording device main body; A memory cartridge that is detachably attached to the recording device main body and stores measurement data at fixed time intervals via an interface within the recording device main body; a first switch that closes or opens the circuit in response to attachment or detachment of the memory cartridge to the recording device main body; and a second switch that closes or opens the circuit in response to locking or unlocking when the memory cartridge is attached to the recording device body. and the closed state of the first and second switches, the closed state of the first switch, and the open state of the second switch represent the mounting state between the recording device main body and the memory cartridge, respectively. a detection circuit that outputs first and second signals; and a first signal from the detection circuit via the interface to enable signal exchange between the recording apparatus main body and the memory cartridge; A data recording device comprising: control means for causing a write operation to be performed from the recording device main body to the memory cartridge at the time of completion.