JP2001203579A - Analog module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an analog module that processes analog data as digital data within a range easily utilized in a system and can restore a parameter to convert an input value into an output value to have a precision set at factory shipment at an optional point of time. SOLUTION: The analog module is provided with a parameter storage means 2 that has a user's area 3 to which a written value by a user is stored and a manufacturer's area 4 to which values written by the manufacture and to be bolded in the module are stored and with a means 5 that copies the values stored in the manufacture's area 4 to the user's area 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an industrial controller, and more particularly, to an analog input module for converting, for example, an analog signal supplied from a sensor into a digital signal within a range easily usable in the controller.
Or, it relates to an analog output module that performs the reverse operation.

[0002]

2. Description of the Related Art FIG. 14 shows a configuration of a conventional analog module. FIG. 1 shows an example of an analog input module that converts an analog input signal into a digital signal within a range that can be easily used in the system and outputs the digital signal. Although an analog output module is also used as an analog module that performs the reverse operation, the present invention will be described using an analog input module as an example. In the analog input module of FIG. 14, for example, a voltage value having a single range is input as an input analog signal.

FIG. 15 is a diagram illustrating gain and offset as conversion parameters when an analog input signal is converted into a digital signal in the analog input module of FIG. 14 and then converted into a converted value to obtain an output signal. FIG. In the figure, the analog input signal
It is assumed that a digitally converted value of -500 to +500 (digit) is output from the module corresponding to a voltage in the 10 to +10 V range.

In the analog input module 50 shown in FIG. 14, an analog input signal is converted into a digital signal by an A / D converter 52 via an input unit 51, and converted by a conversion value processing 53 into a conversion signal stored in an EEPROM 58. Processing is performed using the gain 59a and the offset 59b as parameters, and output to the system bus 54 as digital signals. The operation of the conversion value processing 53 will be described later.

The gain setting 60a operates when the external switch 56 is turned on, writes the output of the A / D converter 52 as a gain 59a into the EEPROM 58, and sets the offset setting 60b when the external switch 57 is turned on. It operates and outputs the output of the A / D converter 52 to the offset 59.
Write it to the EEPROM 58 as b. Normally, the default values of the gain 59a and the offset 59b are written to the analog module at the time of shipment from the factory by the manufacturer.

The microcomputer 55 includes an analog input module 5
0 controls the entire operation of the hardware, such as hardware initialization, conversion value processing in the module, writing to the EEPROM 58, and data transmission to the system bus 54. That is, conversion value processing 53, gain setting 60
Each block of a and the offset setting 60b is not hardware but software processing by the microcomputer 55.

The gain and offset are parameters used for conversion from the output of the A / D converter 52 to a digital signal output to the system bus 54 by the conversion value processing 53. In some cases, a function that allows setting to be performed is given to an analog module.

[0008] This is because when the analog module is installed in a system device or installed in a plant and operates, an applied voltage or an applied current may be applied to a connection partner by an amount corresponding to a full scale of an input range. This may not be possible because of leakage current in the circuit or resistance of the connection cable.

In order to prepare for such a case, before the user operates the analog module, the minimum output value output from the connection destination is stored in the analog module, for example, as a gain, and the minimum output value is output as an offset. , An offset setting function is required.

Next, the operation of the conversion value processing 53 using the gain and the offset will be described. The conversion value processing 53
As described above, it is not actually hardware but software processing performed by the microcomputer 55. The first function is a full scale conversion using a gain and an offset with respect to the output of the A / D converter 52, and the second function is an upper limit value and a lower limit value in a range exceeding the full scale. This is the attachment process.

A specific processing example will be described with reference to FIG. First, as a first procedure, +10 V is applied to the input and the external switch 56 is pressed. At this time, the A / D conversion section 52 has +60
0, and this value is used as the gain 59a in the EEPROM.
58 is written. As a second procedure, 0 V is applied to the input and the external switch 57 is pressed. At this time, the output +10 of the A / D converter 52 is used as the
The data is written to the ROM 58. These procedures need only be performed once when the analog module 50 is used for the first time, and are executed, for example, by a manufacturer at the time of factory shipment.

When +5 V is supplied as an analog input voltage during normal use by a user, A / D
The output of the converter 52 is +305. The function of the conversion value processing 53 is to perform conversion value processing on the output value by the following equation to obtain an output X to the system bus 54.

X = (A / D converter output value−offset) × resolution / (gain−offset) (1) IF X> 500 THEN X = 500 ← Upper limit value pasting IF X <−500 THEN X = −500 ← Past lower limit value The value obtained by this processing is given to the system bus 54 as a digital output. By substituting the above-mentioned gain and offset values and calculating equation (1) with a resolution of 500, the output value X to the system bus 54 is 25
0 (digit) is obtained.

Next, as the EEPROM 58 of FIG.
In many cases, the cost is low due to cost and space constraints on analog modules, and serial EEPROMs in small packages are often used. FIG. 16 shows an example of connection between such a serial EEPROM and a microcomputer, and FIG. 17 shows an example of access to the serial EEPROM.

As a serial EEPROM, only 8
A 256-word × 16-bit (1024 × 16, etc., various memory capacity) memory is stored in a package having only pins. As shown in FIG. 16, a read command is supplied to the Din terminal while giving a ^* CS signal as shown in FIG. By giving a write command or a write command, data at a desired address can be read or data can be written.

As shown in FIG. 17, for example, address 8
There is only one Din terminal for bits, and commands and addresses are serially given to the EEPROM bit by bit. Status and read data from the Dout terminal are also output serially one bit at a time.

As shown in FIG. 17, the status at the time of the read operation is normally 0, which indicates that the data bit subsequently comes out. The same as the start bit in serial communication such as RS232C is the status. On the other hand, during a write operation, a command, an address, and write data are given from the Din terminal, and the status corresponding to the write operation is ready (completed).
Or busy (incomplete) is output.

[0018]

As described above,
In a conventional analog module, the gain and offset values are set so that the input / output characteristics of the analog module are within the accuracy guarantee range when shipped from the factory. However, if the user adjusts the gain and offset in order to cope with a certain usage environment, the gain and offset values written in the EEPROM will be overwritten and will be lost. If you want to reset the gain and offset, send it back to the factory and set the gain and offset values again, or prepare your own high-precision voltage and current generators and reset the gain and offset. There was a problem that had to be.

An analog module having a plurality of ranges as input ranges, for example, -10V to + 10V range, 0 to + 10V range, -5V to + 5V range, 0 to
Some analog modules have five ranges, such as a +5 V range and a +1 V to +5 V range. In such an analog module, if gain and offset values are provided for each range, there is a problem that a large amount of EEPROM capacity is required to write the values and the analog module becomes expensive.

Further, as described above, in the conventional analog module, the serial EEP
Since a ROM is often used and it takes time to read and write data, there is a problem that an analog module having a high conversion speed cannot be obtained.

SUMMARY OF THE INVENTION In view of the above problems, it is an object of the present invention to be able to return the gain and offset values to the accuracy set at the time of shipment from a factory at an arbitrary time, and also to a multi-range module. It is an object of the present invention to provide an analog module which can set a gain and an offset corresponding to only one range at the time of factory shipment, and can further speed up reading and writing of data.

[0022]

FIG. 1 is a block diagram showing the principle configuration of the present invention. FIG. 1 is a block diagram showing the principle configuration of an analog module for processing analog data as digital data in a range that can be easily used in the system, that is, an analog input module or an analog output module.

In FIG. 1, a parameter storage means 2 and a parameter copy means 5 are provided inside the analog module 1. The parameter storage means 2 is, for example, an EEPROM as a rewritable memory, and includes a user area 3 and a maker area 4.

The user area 3 stores parameters written by the user as parameters for converting an input value to an output value.
Is an area for storing parameters to be stored in the module, for example, parameters written by the manufacturer at the time of factory shipment.

The parameter copying means 5 is for copying the parameters stored in the maker area 4 to the user area 3, and this copy is executed at any time. For example, if the user uses a parameter stored in the maker area to convert an input value to an output value at the time of starting use of the analog module, the parameter is copied to the user area by the parameter copy unit 5. used.

For example, even if the user rewrites the parameters, for example, the gain and offset values stored in the user area 3 and uses the analog module at a certain point in time, the user again rewrites the manufacturer area 4 at an arbitrary point in time. Is copied to the user area 3, the analog module can be used again with the accuracy set at the time of factory shipment.

In the embodiment of the present invention, in order to prevent the maker area 4 from being rewritten as an erroneous operation by the user, the parameter stored in the maker area 4 is rewritten externally, for example, by a gain write command from a system bus. May be further provided.

In the embodiment of the present invention, in order to correspond to a plurality of ranges as ranges indicating input value ranges, the input values are stored in the maker area 4 in response to a range change instruction from a user, for example, a user. Parameter correction means for calculating the value of the parameter to be used after the range change by using the parameter which has been changed and storing the calculated value in the user area 3 may be further provided.

In this case, the plurality of ranges are composed of one or more voltage ranges and one or more current ranges, and the maker area 4 stores the voltage parameters and the current parameters. Receives the instruction to change the range from the outside, and uses either the voltage parameter or the current parameter according to whether the changed range is the voltage range or the current range. The value of the parameter to be calculated can also be calculated.

Further, in the embodiment of the present invention, the analog module 1 further includes a high-speed parameter storage means which can copy and store the parameters stored in the user area 3 and which can be read out faster than the parameter storage means 2. You can also.

The analog module according to the present invention is, for example, an analog input / output module for converting an analog / digital input value into a digital / analog value, and a parameter for converting an input value into an output value is, for example, a certain input. Gain and offset corresponding to the value.

The analog module according to the present invention may be configured such that a parameter for converting an input value to an output value is not rewritten by a user. Such an analog module also includes parameter storage means and parameter copy means.

The parameter storage means stores a conversion parameter storage area for storing a parameter for converting an input value into an output value, and a parameter which is written from the manufacturer and which should be held in the module. And a rewritable memory.

The parameter copying means copies the parameters stored in the maker area to the conversion parameter storage area, and thereby converts the parameters stored in the maker area at any time into input values. It can be used to convert to an output value.

In such an analog module,
In order to correspond to a plurality of ranges as ranges indicating input value ranges, in response to an external range change instruction, use the parameters stored in the manufacturer area to change the parameter values to be used after the range change. A parameter correction unit that calculates and stores the parameter in the conversion parameter storage area, and executes rewriting of the parameter stored in the maker area only when an external write command is received;
A maker area rewriting means may be further provided.

As described above, according to the present invention, even if the user generally rewrites the parameters set at the time of factory shipment, for example, the values of gain and offset, the values can be used again at any time. It becomes possible.

[0037]

FIG. 2 is a block diagram showing a configuration of an analog input module according to a first embodiment of the present invention. In the figure, the description of the parts performing the same operation as the conventional example of FIG. 14 is omitted. In FIG. 2, the user setting area 20 and the manufacturer setting area 21 are indicated by thick lines, which indicate emphasis corresponding to the claims. The same applies to other figures.

FIG. 2 is different from FIG.
A user setting area 20 and a manufacturer setting area 21 are provided in the ROM 19, and a gain 20a and an offset 20b are stored in the user setting area 20, and a gain 21a and an offset 21b are also stored in the manufacturer setting area 21. This is a fundamental difference.

In response to this difference, the user setting area 20
Setting 23a, offset setting 23b, and manufacturer setting area 21 for setting a gain and an offset for
Setting 24 for setting gain and offset to
a, offset setting 24b, and user setting area 20
Input to the gain setting 23a and the offset setting 23
switches 22a and 22 for switching between connection to the b side or connection to the manufacturer setting area to copy the gain and offset stored in the manufacturer setting area 21
b is provided.

A mode switch 16 for switching between three modes as a mode for controlling writing of a gain and an offset in the user setting area 20 and the manufacturer setting area 21 is provided. Push button switch for gain 1
7. The offset push button switch 18 corresponds to the external switches 56 and 57 in the conventional example of FIG. 14, and when these switches are pressed, the gain and offset as the output values of the A / D converter 12 are stored in the EEPROM 19. Is stored.

In the analog input module 10 shown in FIG.
A user setting area 20 for setting an offset value and a manufacturer setting area 21 are provided, and a mode switch 16 having three positions is provided. The three modes 0, 1, and 2 of the mode switch have the following meanings when the push button switches 17 and 18 are pressed. First, in mode 0, the user sets the gain and offset. Inside the analog module 10, the gain 20a and the offset 20b are written in the user setting area 20.

In mode 1, the values of the gain 21a and the offset 21b stored in the manufacturer setting area 21 are copied to the user setting area 20 via the switches 22a and 22b, respectively.

In the mode 2, the manufacturer sets the gain and offset. Analog module 10
Is written in the manufacturer setting area 21. Although a rotary switch having three positions is used as the mode switch 16 here, other types of switches other than the rotary switch can be used as long as the three modes can be provided.

In FIG. 2, when the user wants to set the gain and offset values to the values written at the time of factory shipment of the analog input module 10, that is, the values different from the values stored in the manufacturer setting area 21, By setting the mode switch 16 to the 0 position and pressing the push button switch 17 for gain and the push button switch 18 for offset with respect to the specified value of the analog input voltage, the output of the A / D converter 12 is obtained. The values of the gain and the offset are written to the user setting area 20 via the gain setting 23a, the offset setting 23b, and the switches 22a and 22b. When it is desired to use the gain and offset values at the time of factory shipment, the mode switch 16 is set to the position 1 and the two push button switches 17 and 18 are pressed, so that the gain and offset values are set from the manufacturer setting area 21. It is read and stored in the user setting area 20.

FIG. 3 is an explanatory diagram of an analog input module according to the second embodiment. 2, the configuration of the analog input module is the same as that of FIG. 2, except that a write command from the system bus 14 is used to set a gain and an offset in the manufacturer setting area 21. Are different.

In the analog input module 10 of FIG. 2 according to the first embodiment, the user can erroneously set the mode switch 16 to the position 2 and write the gain and offset values in the manufacturer setting area 21. Therefore, the reliability of the analog input module is improved so that the gain and offset values written by the manufacturer are not erased due to such erroneous operation by the user.

A command for gain writing and a command for offset writing, which are not disclosed to the user, can be received from the system bus 14. Only when the command is input and the mode switch 16 is in the position 2, The gain setting 24a and the offset setting 24b are controlled so that the gain or offset can be written in the manufacturer setting area 21 of the EEPROM 19. That is, when the mode switch 16 is in the position 2, the on / off of the push button switches 17 and 18 is invalidated, and even if the user accidentally presses these buttons to set the gain and offset values, Writing of the gain and the offset to the manufacturer setting area 21 is not performed.

When the manufacturer wants to set the gain and offset values, set the mode switch 16 to the position 2 and
In addition, by sending a secret command to the user from the system bus 14 and applying a predetermined analog input voltage and pressing the two push-button switches 17 and 18, the gain and offset values are written in the manufacturer setting area 21. It is.

FIG. 4 is an explanatory diagram of an analog input module according to the third embodiment. 3 is compared with FIG. 3 in the second embodiment, an operation range setting command is given from the system bus 14 in addition to the write command. 20a, and stored as an operation range 20c in addition to the offset 20b. When the setting of the operating range is changed, the gain correction 25a, the offset correction 25b
Thus, the gain 21a, the offset 21b, and the changed operation range 20c stored in the manufacturer setting area 21 are read out, the gain and offset values to be used after the range change are calculated, and the user setting area is calculated. 2
0 is stored as the gain 20a and the offset 20b.

In the third embodiment, the analog input module 10 is a multi-range analog input module that can switch between a plurality of analog input operation ranges. When the user wants to change the operation range, for example, from 0 to 10 V range to 0 to 5 V range, the gain 20a and the offset 20b to be stored in the user setting area 20 are gain correction 25a, offset The result of the correction calculation performed by the correction 25b is written. This correction calculation is actually executed by the microcomputer 15, but the calculation will be described later.

When the manufacturer writes the gain 21 a and the offset 21 b in the manufacturer setting area 21, the corresponding input range is always kept constant, for example, in the range of 0 to 10 V, so that the gain and offset are written in the manufacturer setting area 21. It is not necessary to store in the analog input module 10 the operating range when is set.

FIG. 5 is an explanatory diagram of the flow of the operation range setting command in the third embodiment. The operation range setting command is a command issued by the user and received via the system bus 14. FIG. 5 is an overall view of the controller. Here, an operation range setting command is issued by an application program 31 mounted on the CPU module 30.

The microcomputer 15 inside the analog input module 10 interprets a command from the system bus 14 and
If the command is an operation range setting command, the operation range to be set is stored in the operation range 20c of the user setting area 20 of the EEPROM, and the gain and offset values stored in the manufacturer setting area 21 are read out. Correction according to the range is performed, and stored as a gain 20a and an offset 20b in the user setting area 20. Note that the conversion characteristic of the A / D converter 12 (the slope of the straight line in FIG. 15) is constant even when the operating range is changed.

FIG. 6 is an explanatory diagram of a gain and offset correction calculation in the third embodiment. In FIG. 1, the analog input module 10 has five input ranges, and a gain value corresponding to an input range of 0 to +10 V is stored as A and an offset value is stored as B in the manufacturer setting area 21. Shall be When the user changes to another input range, the values calculated according to FIG. 6 are written by the gain correction 25a and the offset correction 25b as the values of the gains 20a and 20b to be set in the user setting area. Assuming that the values of A and B are, for example, 600 and 10 as described with reference to FIG. 15, the gain value corresponding to the lower three ranges in FIG. 6 is 305 and corresponds to the lowest range. The offset value is 6.
It becomes 9.

FIG. 7 is a flowchart of the gain correction and the offset correction executed by the microcomputer 15. When the process is started in the figure, first, an operation range setting command is received in step S1, a new operation range is written as an operation range 20c in the user setting area 20 in step S2, and a manufacturer setting area is written in step S3. The gain 21a and the offset 21b inside A, that is, A and B are read.

Then, in step S4, the user setting area 20
Is calculated from A and B, and the gain value calculated in step S5 is stored in the user setting area 20.
Is written as the gain 20a. Then step S
At 6, the offset to be written in the user setting area is calculated, the offset calculated at step S7 is written as the offset 20b, and the process ends.

FIGS. 8 to 10 show examples of input / output characteristics in a multi-range analog module. First, in FIG. 8, the input / output characteristics in the -10 V to +10 V range are the same as the output values to the system bus in FIG. -5V ~
In the + 5V range, as described in FIG. 6, the gain value is 305. For example, the output value corresponding to + 5V as the input value is 500 according to the above-described equation (1), and this value is the upper limit value.

FIG. 9 shows input / output characteristics for the 0 to +5 V and 0 to +10 V ranges. The resolution is 1,000 for these ranges, the upper limit is 1,000,
The lower limit is 0.

FIG. 10 shows input / output characteristics for the +1 to +5 V range. For this range, the resolution is
0, the gain is 305, and the offset is 69, as described above. The output value for +1 V is the lower limit value 0, and the output value for +5 V is the upper limit value of 1,000.

FIG. 11 is an explanatory diagram of an analog input module according to the fourth embodiment. In the fourth embodiment, the setting of the gain and the offset by the user is prohibited. Therefore, the mode switch 16 described in FIG.
The two push-button switches 17 and 18 are removed from the analog input module 10, and the setting of the gain and offset in the manufacturer setting area is performed via the system bus 14 by, for example, a manufacturer or a serviceman as in FIG. This is executed by sending a write command.

The gain and offset values stored in the manufacturer setting area 21 can be copied and used as they are as the gain 20a and offset 20b in the user setting area 20. When the user changes the operating range, the gain and offset are corrected and calculated in the same manner as in the third embodiment, and written in the user setting area 20. As described above, if the operation range when the manufacturer writes the gain and offset in the manufacturer setting area 21 is always constant, for example, in the range of 0 to 10 V, it is not necessary to store the operation range in the analog input module. Absent.

In FIG. 11, the user cannot write the values of the gain 20a and the offset 20b in the user setting area. Even if the user changes the range, the gain 21a and the offset 2 written by the manufacturer at the time of shipment from the factory.
1b, the correction calculation is performed, and the result is used for processing the converted value. Therefore, even if the range is changed by the user, the analog input module can always be used in the high accuracy state at the time of shipment from the factory. It becomes possible.

FIG. 12 is an explanatory diagram of an analog input module according to the fifth embodiment. In the fifth embodiment, an analog input module that can use both a voltage input and a current input as an analog input is used. FIG.
2, the analog input is supplied to the A / D converter 12 via the operational amplifier 11a inside the input unit 11, and the input to the operational amplifier 11a is a voltage input substantially applied to both ends of 1 MΩ or both ends of 250Ω. Either the current input applied to the

In order to cope with both the voltage input and the current input, a voltage range gain 21c, a current range gain 21d, a voltage range offset 21e, and a current range offset 21f are provided inside the manufacturer setting area 21. A storage area is provided.

In FIG. 12, when a range setting command for changing the range is input from the user via the system bus 14, the gain for the voltage range depends on whether the changed range is the current range or the voltage range. , Offset for voltage range, or gain for current range,
One of the current range offsets is read out, a correction calculation is made in accordance with the changed operation range, and written as the values of the gain 20a and the offset 20b of the user setting area 20.

FIG. 13 is an explanatory diagram of an analog input module according to the sixth embodiment. In the figure, for example, when compared with FIG.
The difference is that a random access memory (RAM) 32 is provided between the user setting area 20 in the ROM 19 and the conversion value processing 13.

In FIG. 13, for example, at the start of use of the analog input module 10, the gain, offset, and operating range stored in the user setting area 20 are read out from the EEPROM 19 and stored in the RAM 32 so that The conversion value processing in the case of is performed using, for example, gain and offset values set by the manufacturer. As the RAM 32, a built-in one-chip microcomputer may be used, or a RAM device may be provided separately from the microcomputer.

In FIG. 13, in the conversion value processing 13 for the value output from the A / D converter 12, the gain and offset values can be read at high speed, instead of reading the gain and offset values from the EEPROM 19 which takes a long time to read. The gain and offset values can be read from the RAM 32, and the processing can be speeded up.

In the above description, the contents of the invention have been described using the analog input module that converts the analog input signal into a digital signal within a range that can be easily used in the system. However, the present invention is limited to the analog input module. Instead, the present invention can naturally be applied to an analog output module that converts a digital signal into an analog signal.

[0070]

As described above in detail, according to the present invention, even after the user freely changes the gain and offset values according to the use environment, the gain and offset set at the time of shipment from the factory are set. , And the accuracy of the analog input module can be maintained. In addition, even if the user performs an erroneous operation of the external switch, the analog input module can be used with the factory accuracy without destroying the gain and offset values set at the time of factory shipment, thereby improving reliability. it can.

When the user changes the range of the multi-range module, the same accuracy as that at the time of factory shipment can be automatically maintained. In addition, the manufacturer can secure the accuracy for all ranges only by setting the gain and offset for only one range without setting the gain and offset for all ranges.

If an analog module without an external switch is used, an analog module that can reduce the price and can automatically set the gain and offset even when the operating range is changed is provided. Regardless of which range is used in an analog module that has both a voltage range and a current range, the user can set the gain and offset according to the usage environment, and then return to the factory default values. You can also. Further, by storing gain and offset values used for conversion in a high-speed memory, high-speed conversion becomes possible, which greatly contributes to improvement of the practicality of the analog module.

[Brief description of the drawings]

FIG. 1 is a block diagram showing the principle configuration of the present invention.

FIG. 2 is an explanatory diagram of an analog input module according to the first embodiment of the present invention.

FIG. 3 is an explanatory diagram of an analog input module according to a second embodiment.

FIG. 4 is an explanatory diagram of an analog input module according to a third embodiment.

FIG. 5 is a diagram illustrating a flow of an operation range setting command according to the third embodiment.

FIG. 6 is an explanatory diagram of a method of calculating a gain and an offset in a multi-range analog module.

FIG. 7 is a flowchart of a gain and offset correction process according to the third embodiment.

FIG. 8 is a diagram showing input / output characteristics (1) of a multi-range analog module.

FIG. 9 is a diagram showing input / output characteristics (part 2) of a multi-range analog module.

FIG. 10 is a diagram showing input / output characteristics (part 3) of a multi-range analog module.

FIG. 11 is an explanatory diagram of an analog input module according to a fourth embodiment.

FIG. 12 is an explanatory diagram of an analog input module according to a fifth embodiment.

FIG. 13 is an explanatory diagram of an analog input module according to a sixth embodiment.

FIG. 14 is an explanatory diagram of a conventional example of an analog input module.

FIG. 15 is an explanatory diagram of a gain and an offset in the analog input module.

FIG. 16 is a diagram illustrating connection between a microcomputer and a serial EEPROM.

FIG. 17 is a diagram illustrating an access example of a serial EEPROM.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Analog module 2 Parameter storage means 3 User area 4 Maker area 5 Parameter copy means 10 Analog input module 11 Input part 12 A / D conversion part 13 Conversion value processing 14 System bus 15 Microcomputer 16 Mode switch 17 Gain pushbutton switch 18 push button switch for offset 19 EEPROM 20 user setting area 21 manufacturer setting area 30 CPU module 31 application program 32 random access memory (RAM)

Claims (9)

[Claims] 1. An analog module for processing analog data as digital data in a range which can be easily used in a system, wherein a user stores a parameter for converting an input value into an output value and which is written by a user. Parameter storage means having a storage area for storing parameters which are written from the maker side and which are to be held in the module; and storing the parameters stored in the storage area for the user in the storage area for the user. An analog module, comprising: parameter copying means for copying, wherein a parameter stored in a maker area can be used at any time to convert the input value into an output value. 2. The analog module according to claim 1, wherein in the analog module, the parameter storage unit includes a rewritable memory. 3. The analog module according to claim 2, further comprising a maker area rewriting restricting means for executing rewriting of parameters stored in the maker area only when an external write command is received. 3. The analog module according to claim 2, wherein 4. In the analog module, in order to correspond to a plurality of ranges as a range indicating the range of the input value, the analog module receives a range change instruction from the outside,
3. The analog according to claim 2, further comprising a parameter correction unit that calculates a value of a parameter to be used after the range conversion using the parameter stored in the maker area, and stores the parameter value in the user area. module. 5. The plurality of ranges include one or more voltage ranges and one or more current ranges, and the maker area stores a voltage parameter and a current parameter. In response to the instruction to change the range from the outside, the range is changed using either the voltage parameter or the current parameter in accordance with whether the changed range is the voltage range or the current range. The analog module according to claim 4, wherein a value of a parameter to be used later is calculated. 6. The analog module according to claim 1, further comprising a high-speed parameter storage unit in which parameters stored in the user area are copied and stored, and which can be read out faster than the parameter storage unit. Item 7. An analog module according to Item 1. 7. The analog module according to claim 1, wherein parameters for converting the input value into an output value are a gain and an offset respectively corresponding to a certain input value. 8. An analog module for processing analog data as digital data in a range which can be easily used in a system, comprising: a conversion parameter storage area for storing a parameter for converting an input value into an output value; A parameter storage means including a maker area for storing parameters to be held in the module, the parameters being written from the module, and a parameter storage means comprising a rewritable memory; Analog copying means for copying a parameter stored in a maker area at any time to convert the input value into an output value. module. 9. The analog module uses a parameter stored in the maker area in response to an external range change instruction to correspond to a plurality of ranges as the range indicating the input value range. Parameter correction means for calculating the value of the parameter to be used after the range change and storing the parameter in the conversion parameter storage area, and rewriting the parameter stored in the maker area by receiving a write command from the outside. 9. The analog module according to claim 8, further comprising: a maker area rewriting means that executes only when the time has elapsed.