JP3191247B2 - Signal processing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a signal processing apparatus for executing predetermined signal processing by a microprocessor, outputting the processed signal to a load side, and changing the processing state of the signal processing by a switch signal from a switch. The present invention relates to a signal processing device improved so that a switch does not malfunction.

[0002]

2. Description of the Related Art FIG. 4 is a block diagram showing a configuration of a conventional signal processing device. A two-wire signal transmitter is shown as an example of the signal processing device in this case. Reference numeral 10 denotes a two-wire signal transmitter that converts a physical quantity such as a process variable into an electric signal and transmits the electric signal. Power is supplied from a DC power supply 11 via a load 12. DC power supply 11 and load 12 are stored in receiving instrument 13.

[0003] The electrical signal is transmitted to the transmission line L _1, L ₂ by two-wire signal transmitter 10 as a current signal I _L, receiver 13 knows the process variable by detecting the voltage change developed across the load 12 .

[0004] current signal I _L is transmitted by, for example, two-wire signal transmitter 10 which is set to the range corresponding to the pressure in the piping is converted into a unified current of 4~20mA the receiver 13 of the load At the same time, a 4-digit digital display is displayed on the monitor.

In this case, for example, when it is desired to change the pressure range, change various parameters, or monitor, it is convenient if the two-wire signal transmitter 10 can be operated from outside.

For this reason, the handheld terminal 14 is connected as necessary using transmission lines L ₁ ′ and L ₂ ′, and the two-wire signal transmitter 10 has a dedicated data communication function with the handheld terminal 14. Then, digital data such as parameter change is transmitted from the handheld terminal 14 to the two-wire signal transmitter 10.

The two-wire signal transmitter 10 has the following configuration with respect to the overall configuration described above. SNR is a detector (sensor) that detects pressure / differential pressure and converts it into an electric signal. The converted analog signal is converted into a digital signal by an analog / digital converter A / D, and the converted signal is transmitted through a microprocessor μP. Is stored in the random access memory portion of the memory MEM1.

Using the stored digital signal, the microprocessor μP executes a predetermined operation such as linearization according to an operation procedure written in, for example, a read-only memory portion of the memory MEM1, and performs a digital / analog conversion by the digital / analog converter D / A. It outputs to the output circuit OPC via A.

On the other hand, a predetermined calculation result by the microprocessor μP is digitally displayed in a necessary number of digits on a built-in monitor LCD. The output circuit OPC converts the voltage signal converted into an analog signal by the digital / analog converter D / A into 4 to
Is converted into a unified current signal I _L of 20mA is transmitted to receiver 13 via the transmission line L _1, L _2.

Further, the output circuit OPC make power of an internal circuit of two-wire signal transmitter 10 with a portion of the current signal I _L. In this case, for example, the monitor LCD current signal I _L
Is digitally displayed.

The RTE is a rotary encoder as shown in FIG. By rotating the operation axis SFT, for example, when the rotation is in the forward direction, the two adjacent pulse signals A and B generated by the rotation have a predetermined phase difference determined by the rotation direction as shown in FIG. Is output. When the rotation is in the opposite direction, two adjacent pulse signals A and B generated by the rotation are output while maintaining a phase difference opposite to that in the case of FIG. 6A as shown in FIG. 6B. You.

The interface circuit INF uses the pulse signals A and B to generate a binary number of pulses corresponding to the number of revolutions at which software processing is easily performed as shown in FIG. 6 (a) or 6 (b). The rotation number signal X of the rectangular wave of FIG.
(B)), and outputs a low-level or high-level direction signal Y (FIGS. 6 (a) and 6 (b)) corresponding to the rotation direction to the microprocessor μP as an interrupt signal via the switch SW to zero. Set points, span, etc.

The IFC is an interface for performing data communication with the handheld terminal 14, and is connected between the transmission lines L ₁ and L ₂ and the microprocessor μP.
The digital signals from the transmission lines L ₁ and L ₂ are transmitted as parallel data to the microprocessor μP, and the data from the microprocessor μP are transmitted as serial signals to the transmission lines L ₁ and L _2.
It has the function of transmitting to the side.

Next, the handheld terminal 14 is configured as follows. SER is a setting device operated by an operator, has a built-in monitor, and changes a mode for switching between the zero adjustment and the span adjustment of the two-wire signal transmitter 10, requests a model, changes a display resolution, changes a range, and detects an abnormality. , or it can be a variety of settings or request a display of the value of the current signal I _L.

ΜP ′ is a microprocessor, for example, to which data from a setter SER is inputted,
In accordance with the processing procedure stored in the interface IF
A digital signal is transmitted to the two-wire signal transmitter 10 via C '.

The microprocessor μP ′ converts the response data from the two-wire signal transmitter 10 into an interface I.
The data is taken into the memory MEM 'via the FC', and is decoded according to the processing procedure stored in the memory MEM 'and displayed on the monitor of the setting unit SER.

[0017]

However, in a normal switch operation with such a switch SW, for example, as shown in FIG. 7A, a switch process is performed several seconds after the switch SW is switched from off to on. To start,
When the switch SW is broken and is in the on state (FIG. 7B), the processing is immediately executed when the power is turned on, so that there is a problem of causing a malfunction.

In this way, the process is started a few seconds after the switch SW is turned on, for example, when the zero point is adjusted, the zero pressure is applied to the detector SNR and the adjustment is performed in a stable state. However, it takes several seconds before the zero pressure is actually applied and the adjustment becomes possible.

[0019]

According to the present invention, as a configuration for solving the above-mentioned problems, a signal transmission device is provided.
The microprocessor executes predetermined signal processing, and
Process results to the receiving instrument, and
Signal for changing the processing state of the signal processing by the switch signal.
In the signal processing device, the microprocessor includes a power supply
Reads the operation status of the switch when turned on
A state determining means for determining on / off, the ON state DOO
The dedicated flag is set in the memory
To a state control means for resetting only flag, dedicated off
When lag is reset, signal processing by switch signal
Starting means.

[0020]

[Operation] The state judging means reads the operation state of the switch by the microprocessor when the power is turned on, and judges ON / OFF of the switch. The state control means includes an on-state
The dedicated flag is set in the memory
, The dedicated flag is reset.

When the dedicated flag is reset,
Signal processing by the switch signal is started. By checking the state of the switch after turning on the power in this manner, the operation can be prohibited even when the switch is in the operating state, and malfunction can be prevented.

[0022]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing the configuration of one embodiment of the present invention. Parts having the same functions as those of the two-wire signal transmitter as the conventional signal processing apparatus shown in FIGS. 4 to 6 are denoted by the same reference numerals, and description thereof will be omitted as appropriate. The present invention will also be described by taking a two-wire signal transmitter as an example of a signal processing device.

The two-wire signal transmitter 15 has a detector SNR,
Analog / digital converter A / D, microprocessor μP, monitor LCD, digital / analog converter D /
A, output circuit OPC, interface circuit IFC, I
The NF, the rotary encoder RTE, the switch SW, and the like are the same as the two-wire signal transmitter 10, except that the memory MEM1 is changed to the memory MEM2.

The memory MEM2 has a memory MEM1
An arithmetic program having a different content from the above is stored.
As a result, the operation by the microprocessor μP has a different operation content from the conventional operation. Hereinafter, these will be described with reference to the flowchart shown in FIG. 2 and the state diagram shown in FIG.

The contents of the calculation in the normal processing are the same as those of the two-wire signal transmitter 10 shown in FIG. 4, but the procedure of the processing for taking in data from the rotary encoder RTE via the switch SW is different. .

As shown in FIG. 3A, when the power is turned on (step 1), the process proceeds to step 2 where the microprocessor μP switches the switch SW in accordance with the program stored in the memory MEM2. Check the operation status.

As a result, if the operation state of the switch SW is on (A in FIG. 3B), the microprocessor μ
P sets a dedicated flag in a flag dedicated area of the memory MEM2 (step 3). While the dedicated flag is set (period A in FIG. 3B), the switch S
The operation by W is prohibited (step 4).

Next, the process proceeds to step 5, where the switch SW
It is determined whether or not the operation state has been released. If it has not been released, the process proceeds to step 4 and the switch operation is prohibited.

If it has been released, the process goes to step 6 to reset the dedicated flag (B in FIG. 3B) so that the switch SW can be operated, and the normal operation mode in step 7 (FIG. The process proceeds to C) of FIG.
The switch process is started at D in (b).

As described above, the switch operation is released a few seconds after the switch SW is turned on, and the switch operation is performed thereafter. However, if the release of the switch operation is earlier than expected, the switch operation processing is not executed. By doing so, the reliability is improved. This is because, for example, it is determined that the release operation has been started due to noise or the like, and a malfunction can be prevented.

Further, the reliability can be improved even if two switches SW are used and the operation is executed only when the two switches SW are simultaneously turned on by a combination of the on / off states. Can be done.

[0032]

As described above, according to the present invention, the state of the switch is confirmed after the power is turned on, so that the operation is prohibited even if the switch is in the operating state. Erroneous operation can be prevented.

[Brief description of the drawings]

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

FIG. 2 is a flowchart showing a calculation procedure for executing the embodiment shown in FIG. 1;

FIG. 3 is a state diagram for executing the embodiment shown in FIG. 1;

FIG. 4 is a block diagram showing a configuration of a conventional two-wire signal transmitter.

FIG. 5 is a configuration diagram showing specific contents of a rotary encoder shown in FIG. 4;

FIG. 6 is a waveform chart for explaining the operation of the rotary encoder shown in FIG.

FIG. 7 is a state diagram showing a state of switch processing of the two-wire signal transmitter shown in FIG. 4;

[Explanation of symbols]

 10, 15 Two-wire signal transmitter 11 DC power supply 12 Load 13 Receiver 14 Handheld terminal RTE Rotary encoder MEM1, MEM2 Memory SW switch

Continuation of front page (58) Fields investigated (Int. Cl. ⁷ , DB name) H04B 3/54 G08C 19/02 H02J 13/00 Patent file (PATOLIS)

Claims (1)

(57) [Claims] 1. A provided in the signal transmitter, by performing a predetermined signal processing by the microprocessor, receives a processing result meter
In the signal processing device, which outputs the signal processing state to the signal processing unit and changes the processing state of the signal processing by a switch signal from the switch, the microprocessor reads the operation state of the switch when power is turned on to determine whether the switch is on or off. When the state is determined , the dedicated flag is set in the memory when the state is ON, and the ON state is set.
State control method that resets the dedicated flag when the
Signal by switch signal when stage and dedicated flag is reset
Means for initiating processing.