JPH0720571Y2 - Recorder - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Use The present invention relates to a recorder for storing changes in physical quantity and chemical quantity in a storage medium such as a floppy disk in an industrial plant or a laboratory.

(B) Conventional technology Conventional recorders convert measured signals, that is, input signals into digital signals with an A / D converter, capture them at a predetermined cycle, and sequentially store them in a storage area of a storage medium such as a floppy disk. I remember it. The data stored in the storage medium is the bit configuration of the digital signal taken in by the A / D converter.

(C) Problems to be Solved by the Invention In the above-mentioned conventional recorder, the bit configuration of the data taken in at each sampling is the same. Therefore, when the bit structure of one data is large and the sampling period is short, a large capacity storage medium is required to store the data. Using one with a small storage capacity quickly fills it up, requires replacement and is cumbersome and cumbersome. In order to use one storage medium as long as possible, it is sufficient to reduce the bit configuration of data and lengthen the sampling cycle, but this cannot perform accurate recording.

The present invention has been made in view of the above problems, and an object thereof is to provide a recorder capable of storing as much data as possible in one storage medium without lowering the data accuracy. There is.

(D) Means and Actions for Solving the Problems The recorder of the present invention is one in which input data is sampled and taken in at a predetermined cycle and stored in the storage means as digital data. Difference value calculating means for obtaining a difference value of sampling digital data, and all bits of the digital data are stored in a predetermined reference area of the storage means. Storage control means for controlling the storage of the value.

In this recorder, when the input data is taken in by sampling, the storage area of the storage means for storing the data is a reference area, for example, if the storage means is a floppy disk, it is determined whether it is the head area of the block, and if it is the reference area. , All the bits of the data captured this time are stored there.
Then, in the subsequent sampling, the difference value between the current data and the previous data is obtained by the difference value calculation means, and this difference value is stored. Generally, since the change of data is very small, the difference value can be stored as small-bit data, so that the total number of data that can be stored in one block in the same sampling period increases.

(E) Embodiment Hereinafter, the present invention will be described in more detail with reference to embodiments.

FIG. 2 is a block diagram of a recorder in which the present invention is implemented. This recorder is a multi-channel analog measurement signal
I _1, I _2, ..., I _n is separated into respective channels by the multiplexer 1, further taken into CPU3 is converted into a digital signal by the A / D converter 2. The data is taken into the CPU 3 at a predetermined sampling cycle, and the taken data is temporarily stored in the RAM 4. Then, the data is dropped and stored in the floppy disk 6 for storing the data for a long period of time. The ROM 6 is provided for storing the program of the CPU 3.

The CPU 3 has a function of calculating a difference value between the fetched data D _i and the previous data D _i−1, and when the storage area of the floppy disk 6 in which the current data is to be stored is the head area of the block. Has a function of storing the data D _i , and thereafter, controlling to sequentially store the difference value for each sampling of the data.

In this embodiment, the types of data stored in the floppy disk 6 are divided into four types (a) to (d) shown in FIG. In the type (a), the data part has 14 bits, and the captured data D _i corresponds to this. 16 bits including 2 bits of the type identification part. The (b) type has a 10-bit data section, the (c) type has a 6-bit data section, and the (d) type has a 2-bit data section. The types (b) to (d) correspond to the difference value D _d , and when the difference value D _d is −2 to 1, the type (d) is the difference value D _d.
Is -32 to 31, except for -2 to 1, the (c) type is
The type (b) is selected when the difference value D _d is −512 to 511 except for −32 to 31.

Next, the data storage processing operation of the recorder of the above embodiment will be described with reference to the flow chart shown in FIG.

Every time the data sampling time comes, the data D _i is read this time (step ST1). Then, this data D _i is temporarily stored in the RAM 4. Next, it is determined whether or not the area of the floppy disk 6 in which this data D _i is to be stored is the head block (step ST2). If it is the head block, the data D _i acquired this time is (a). The type is stored in the head area of the floppy disk 6.
That is, the data D _i is stored as it is for 14 bits (step ST3), and the process returns. Next, when the sampling time arrives, D _i is similarly taken in (step ST1), and it is determined whether or not the storage area is the head block (step ST2).
Is the judgment NO this time, and therefore, the (current intake value D _i ) − (previous D _i−1 ) is obtained as the difference value D _d (step ST4), and this difference value D _d is −2 or more. It is determined whether it is 1 or less (step ST5). When the difference value D _d is very small and is within this range, the determination is YES, and in this case, the data D _d is stored in the (d) type, that is, the data portion is 2
The bit data is stored in the floppy disk 6. If D _d does not belong to −2 or more and 1 or less in step ST5, it is further determined in step ST7 whether D _d is −32 or more and 31 or less. If the difference value D _d is within this range, this determination is YES, and in this case, the data D _d
Is stored as type (c) (step ST8). That is, the data portion is stored as 6-bit data in the next storage area of the floppy disk 6, and the process returns. If D _d is not −32 or more and 31 or less in the determination in step ST7,
Next, in step ST9, it is determined whether or not the difference value D _d is −512 or more and 511 or less, and if it is within this predetermined range, the data
D _d is stored in the (b) type, that is, 10 bits are stored as data in the area of the floppy disk 6 and the process is returned. Even in this step ST9, if D _d is not within the predetermined range, the data D _d is stored as the (a) type, that is, the difference value D _d is very large, that is, the difference data D _d is not stored, but the data itself is stored. Memorize (step ST
11). However, usually in a recorder, the change of the data D _i is very small, and the data at the time of this sampling,
Generally, there is almost no difference from the data at the time of the previous sampling, and it is rare that D _d becomes extremely large. Therefore, usually (c) or (d) type can be used. , It is possible to greatly save the storage capacity of the floppy disk. For example, if the first decimal number data is 6012, and is changed to 5988, 5958, 5910, 5911, and so on, the first data 6012 is stored as it is in the first block as 14-bit data, After that, the difference and the next difference values −24, −30, −48, and +1 are sequentially recorded as data. And -24,
-30 is the (c) type, -48 is the (b) type, and +1 is stored as the (d) type data. When such five 14-bit data are summed up, it can actually be stored in 6 bytes.

When reading the data stored as described above, first read the first data as it is, and from the next data, look at the type identification section to determine the data length, and determine the data determined for each data type. It is sufficient to read the part and take the sum with the previous data.

An example of the data format stored in the floppy disk 6 of the recorder of the above embodiment is shown in FIG. 4 (a). That is, 14-bit data is stored as it is in the first block, and thereafter, the 2-bit code of the type identification section and the bits of the data corresponding to the type identification section follow.

In the above embodiment, two bits of the type identification section are provided at the beginning of the data, but it is also possible to combine the identification sections into a table and store the identification section and the data section separately in the block. Such an example is shown in FIG. 4 (b).
Further, in the above-mentioned embodiment, the case where the fetched data D _i is sequentially stored in the floppy disk is taken as an example, but the data is temporarily stored in the RAM before being dropped to the floppy disk 6, and one block is stored in the RAM 4. The minute data may be accumulated and then transferred to the floppy disk 6.
In this case, all the data types in the block can be unified. For example, if the previous data are all within 6 bits, the difference value is unified to 6 bits, and as shown in FIG. 4 (c), a type identification code is first provided as data following all bit data of the first block, After that, only the changed amount of data may be sequentially stored. When the absolute value of the change in the data is small and the variation is small,
It is more effective in increasing the number of data.

(F) Effect of the device According to this device, all the bits of the acquired data are stored in the reference area of the storage device when the data is captured at each sampling time, dropped in the storage device, and stored. For each subsequent area, the difference value between the current data and the previous data is calculated, and this difference value is stored sequentially, so normally the difference value has a much smaller number of data bits than the previous data. Therefore, the bit capacity for storing data is small as a whole, and more data can be recorded in the storage means having a constant capacity.

[Brief description of drawings]

FIG. 1 is a flow chart showing a read processing operation of a recorder according to an embodiment of the present invention, FIG. 2 is a block diagram of a recorder according to the present invention, and FIG. 3 is a recorder of the embodiment. FIG. 4 (a) for explaining the data storage format of FIG.
Is a diagram showing an example of continuous data storage of the recorder of the above embodiment, FIG. 4 (b) is a diagram showing an example of data storage of another embodiment, and FIG. 4 (c) is another embodiment. 3 is a diagram showing an example of data storage of FIG. 2: A / D converter, 3: CPU, 4: RAM, 6: Floppy disk.

Claims (1)

[Scope of utility model registration request] 1. A recorder for sampling input data at a predetermined cycle and taking it in and storing it as digital data in a storage means, a difference value calculating means for obtaining a difference value between digital data at the current sampling and digital data at the previous sampling. And storage control means for storing all bits of the digital data in a predetermined reference area of the storage means, and for data following the data in which all the bits are stored, controlling so as to store the difference value. Recorder characterized by having.