JP3307830B2 - Communication system between the transmitter that outputs pulse signals and the communication terminal - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a communication system with a transmitter for outputting a pulse signal having a weight of a measured amount.
More specifically, this is a communication method in which a transmitter that converts a signal output from a measuring device into a pulse signal and outputs the pulse signal can communicate using a communication terminal device that communicates with the transmitter.

[0002]

2. Description of the Related Art In the fluid industry, state quantities such as temperature, pressure, viscosity, density, pH value, volume flow rate, and mass flow rate are measured according to the purpose. In these measurements, centralized measurement management is usually performed. The above-mentioned state quantity is mainly transmitted by a two-wire transmission method of an analog signal having a span width of 4 to 20 mA,
On the receiving side, a resistance load is connected and converted into a voltage signal to be a control target signal. For example, in a flow meter, a flow signal output in proportion to the flow rate is converted into a current signal by a transmitter,
Further, the current signal is amplified and shaped to transmit the current signal within the span width. These zero adjustments and specification changes are performed by changing the circuit constants of the electric circuit in the transmitter, but usually the transmitter is integrated with the body of the flow meter. When the place is remote, it takes time for the adjustment work, which is inconvenient. For this reason, communication terminals have been developed in which adjustment is made by remote communication using the output signal line of the transmitter.

A communication terminal superimposes a communication signal obtained by modulating desired information into a frequency, an amplitude or a phase on an analog signal transmitted from a transmitter to a receiver via a two-wire output signal line. Then, it communicates with the electric circuit built in the transmitter according to the protocol to set the measurement range, adjust the zero point, display the flow rate, adjust the span, check the maintenance information, diagnose, etc. Yes, many are portable. As described above, the communication terminal communicates with the transmitter via the output signal line using the communication signal.As an example, the communication when the pulse signal is output from the transmitter of the flow meter is frequency-modulated. The case where the method is used will be described below.

FIG. 4 is a waveform diagram for explaining communication between a conventional transmitter for outputting a pulse signal and a communication terminal, and FIG. 4A shows a communication waveform when a pulse signal is not output. FIG. 4B is a communication waveform when a pulse signal is output, 10 is a communication signal, 11 is a constant level signal, 1
2 is a pulse signal.

[0005] As shown in FIG. 4 (A), when the pulse signal is not output, 0 (zero) is a constant level signal 11 of larger constant current than mA, the communication period T _11, the constant level signal 11 On the other hand, communication can be performed by superimposing the communication signal 10. However, as shown in FIG. 4 (B), when the pulse signal 12 is output during the communication period T ₁₂ is launched pulse signal 12, the communication signal 10 by deactivation is disconnected, due to the communication signal 10 Communication becomes impossible.

[0006]

SUMMARY OF THE INVENTION In a measuring device having an output signal line for transmitting two lines of a pulse signal output from a transmitter of a flow meter, a communication terminal device is connected during a measurement period in which the pulse signal is output. It is impossible to communicate with a transmitter using a communication signal. For this reason, in order to perform communication, it is necessary to temporarily stop the measurement so as not to output the pulse signal. However, when a fluid is flowing constantly as in a chemical device, the flow is hardly stopped. For this reason, there was a problem that communication with the transmitter could not be performed immediately using the communication terminal during operation of the chemical device.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described circumstances, and is intended for communication between a transmitter and a communication terminal without stopping a flow in a measuring device that outputs a pulse signal, such as a transmitter of a flow meter. It is intended to be able to perform.

[0008]

According to a first aspect of the present invention, an output signal line of a transmitter having a communication function of processing a signal from a measuring device and outputting a pulse signal having a weight of a measured amount is output. Connect, using a communication terminal device that performs communication by superimposing a communication signal on the output signal, read the measurement amount, change the specification of the measurement device, adjust or check, etc. After the power is turned on, the pulse signal is not output until a certain period of time, and a communication waiting period for waiting for a communication signal from the communication terminal is set, and a communication signal from the communication terminal is not received within the communication waiting period. The transmitter is in a measurement mode for outputting a pulse signal, and when receiving a communication signal from the communication terminal within the communication waiting period, the transmitter is turned off until the transmitter is turned off. In the communication mode, a communication mode enabling communication with the communication terminal device is provided.In the communication mode, even if a signal is input from the measuring device, communication is prioritized without outputting the pulse signal. It was made.

According to a second aspect of the present invention, a signal from a measuring device is arithmetically processed and connected to an output signal line of a transmitter having a communication function of outputting a pulse signal having a weight of a measured amount,
Using a communication terminal device that performs communication by superimposing a communication signal on an output signal, in a communication method for reading a measured amount, changing specifications of a measuring device, adjusting or checking, etc., after turning on the power to the transmitter. Without outputting the pulse signal up to a certain time, a communication waiting period for waiting for a communication signal from the communication terminal, and when the communication signal from the communication terminal is not received within the communication waiting period, the transmission is performed. The device is in a measurement mode for outputting a pulse signal, and when a communication signal from the communication terminal device is received within the communication waiting period, the transmitter is connected to the communication terminal until a predetermined time elapses after the end of communication. Communication mode that enables communication with the device, and in the communication mode, even if a signal from the measuring device is input, priority is given to communication without outputting the pulse signal. It is obtained by way.

According to a third aspect of the present invention, in the measurement mode according to the first or second aspect of the present invention, when there is no signal from the measuring device and the pulse signal is not output, the transmitter is connected to the communication terminal. The communication mode is switched from the measurement mode to the communication mode when a communication signal from the communication device is received.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In order to explain an embodiment of a communication system between a transmitter for outputting a pulse signal and a communication terminal according to the present invention, an outline of a communication process between a measuring apparatus and a communication terminal according to the present invention will be described. The case of a flow meter will be described.

FIG. 1 is a diagram for explaining an outline of a communication process between a measuring device and a communication terminal according to the present invention. In FIG. 1, 1 is a flow meter, 2 is a transmitter, 3 is an electric circuit, 4a, 4
b is an output signal line, 5 is a receiver, 6 is a power supply, and 7 is a communication terminal.

In FIG. 1, a flow meter 1 outputs a flow signal proportional to the flow rate. A transmitter 2 is integrally attached to the flow meter 1, and an electric circuit 3 is housed in the transmitter 2.

The electric circuit 3 is connected to a receiver 5 via output signal lines 4a and 4b for transmitting a pulse signal. Inside the receiver 5, a signal detection resistor _RL and a power supply 6 are connected in series. I have. The power supply 6 supplied to the electric circuit 3 is turned ON / OFF by a switch SW.

A communication terminal 7 is connected to the output signal lines 4a and 4b, as required, at positions 7a and 7b. As the communication terminal 7, a personal computer, a handheld terminal or the like capable of transmitting and receiving communication signals is used. The communication terminal 7 is operated to communicate with the transmitter 2.

According to the communication system between the transmitter for outputting a pulse signal and the communication terminal according to the present invention, the transmitter 2 communicates during the communication waiting period in order to eliminate the period in which the pulse signal and the communication signal for communication are matched. This communication method switches between the measurement mode and the communication mode depending on whether or not a communication signal from the terminal device 7 is received. This will be described below.

FIG. 2 is a first embodiment of a waveform time chart for explaining a communication system between a transmitter for outputting a pulse signal and a communication terminal according to the present invention.
FIG. 2B shows a case where the transmitter 2 enters the measurement mode without receiving the communication signal from the communication terminal 7 during the communication waiting period. FIG.
This is the case where the communication mode is received and the communication mode is set.

In FIG. 2A, the output signal line 4a
When the power is turned on to the transmitter 2 at time t _0A by the switch SW, the fixed time T from time t _0A to time t _1A becomes:
This is a communication waiting period for waiting for reception of a communication signal from the communication terminal device 7. During this communication waiting period, even if the flow signal is output from the flow meter 1, the pulse signal is not output from the transmitter 2. If the communication signal from the communication terminal 7 to the transmitter 2 is not received within the communication waiting period, the pulse signal 12 is output if the flow signal is output from the flow meter 1 at time t _1A at the end of the communication waiting period. Is output to switch to the measurement mode. Note that even when the flow signal from the flow meter 1 is not output at time t _1A , the measurement mode is set and the output is L (LO
W) The pulse signal 12 is output at the time when the flow rate signal is output from the flow meter 1 when the signal is output as the constant level signal 11 of the level.

In FIG. 2B, the output signal line 4
When the power of the transmitter 2 is turned on at time t _0B by the switch SW in FIG. 2A, the communication waiting period is up to a certain time T as in FIG. 2A. During this communication waiting period, even if the flow signal is output from the flow meter 1, the pulse signal is not output from the transmitter 2. When a communication signal from the communication terminal 7 to the transmitter 2 is received within a certain time T, for example, at time t _1B , the communication waiting period ends at that time, and the communication mode is switched to a communication mode that enables communication. Be replaced. During the communication mode,
The period from the communication start time t _1B to the time t _3B when the power is turned off after the communication period from the communication end time t _2B has elapsed. When the power is turned on again at time t _4B after time t _3B when the power is turned off, the communication waiting period is from time t _4B to time t _5B from the time t _4B to the fixed time T. if received the communication signal to the transmitter 2, it is possible to switched measured after time t _5B the measurement mode to output a pulse signal 12. It should be noted that, after the communication mode end, once off the power, but was not allowed to become a measurement mode to be turned on the power again, and until the end of communication time t _2B and communication mode, up to a certain period of time followed after the communication mode end T In the communication waiting period, the measurement mode may be entered after the communication waiting period from the communication mode without turning off the power.

FIG. 3 is a second embodiment of a waveform time chart for explaining a communication system between a transmitter for outputting a pulse signal and a communication terminal according to the present invention.

In FIG. 3, the flow meter 1 is in the measurement mode.
From the time t _{1C when} the flow rate signal from the flow meter 1 is stopped and the pulse signal 12 is no longer output from the time t _1C when the constant level signal 11 is continuously output, for example, at the time t _2C . When the communication signal from the transmitter 7 to the transmitter 2 is received, the measurement mode ends at that point and the mode is switched to the communication mode. After switching to the communication mode, the operation is as described with reference to FIG.

[0022]

【The invention's effect】

Advantageous Effects According to Claim 1: Connected to an output signal line of a transmitter having a communication function of processing a signal from a measuring device and outputting a pulse signal having a weight of a measured amount, and a communication signal as an output signal Using a communication terminal that performs communication by superimposing
In a communication method for performing adjustment, inspection, or the like, after turning on the power to the transmitter, the pulse signal is not output until a predetermined time, and a communication waiting period for waiting for a communication signal from the communication terminal is set. When a communication signal from the communication terminal is not received within the period, the transmitter enters a measurement mode for outputting a pulse signal, and when a communication signal from the communication terminal is received within the communication waiting period, Until the power of the transmitter is turned off, the transmitter is set to a communication mode that enables communication with the communication terminal, and in the communication mode, a signal from the measuring device is transmitted. Even if input, the priority is given to communication without outputting the pulse signal. Therefore, even if the pulse signal is output, the mode can be easily switched by turning off and on the power supply. Also, during the communication mode, no pulse signal is output and the communication signal is output with priority, so that the communication signal is not interrupted due to the pulse signal, and the transmission can be performed without stopping the measurement. Communication with the communication terminal can be reliably performed.

According to a second aspect of the present invention, a signal from a measuring device is arithmetically processed and connected to an output signal line of a transmitter having a communication function for outputting a pulse signal having a weight of a measured amount. Using a communication terminal that performs communication by superimposing a communication signal on a communication terminal, in a communication method for reading a measured amount, changing specifications of a measuring device, adjusting or checking, etc. Up to time without outputting the pulse signal, a communication waiting period for waiting for a communication signal from the communication terminal, when the communication signal is not received from the communication terminal within the communication waiting period, the transmitter is The transmitter enters a measurement mode for outputting a pulse signal, and when a communication signal from the communication terminal is received within the communication waiting period, the transmitter performs the communication until a certain time elapses after the communication ends. In the communication mode, a communication mode enabling communication with a terminal device is set. In the communication mode, even when a signal from the measuring device is input, communication is prioritized without outputting the pulse signal. Therefore, the same effect as the first aspect can be obtained.

Advantageous Effect Corresponding to Claim 3: Claim 1 or 2
In the communication method between the transmitter that outputs the pulse signal and the communication terminal device according to the above, in the measurement mode, when there is no signal from the measurement device and the pulse signal is not output, the transmitter performs the communication. When a communication signal is received from the terminal device, the mode is switched from the measurement mode to the communication mode. Therefore, while the pulse signal is not output in the measurement mode, the mode is switched to the communication mode without turning off / on the power. Also, even if the pulse signal starts to be output during the communication mode, the communication signal is output with priority without outputting the pulse signal, thereby preventing the communication signal from being disconnected by the pulse signal. it can.

[Brief description of the drawings]

FIG. 1 is a diagram for explaining an outline of a communication process between a measuring device and a communication terminal device according to the present invention.

FIG. 2 is a first embodiment of a waveform time chart for explaining a communication system between a transmitter for outputting a pulse signal and a communication terminal according to the present invention.

FIG. 3 is a second embodiment of a waveform time chart for explaining a communication system between a transmitter for outputting a pulse signal and a communication terminal according to the present invention.

FIG. 4 is a waveform diagram for explaining communication between a conventional transmitter that outputs a pulse signal and a communication terminal.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Flow meter, 2 ... Transmitter, 3 ... Electric circuit, 4a, 4b ...
Output signal line, 5: receiver, 6: power supply, 7: communication terminal, 10: communication signal, 11: constant level signal, 12: pulse signal, ... communication waiting period, ... measurement mode, ... communication mode.

──────────────────────────────────────────────────続 き Continued on the front page (58) Fields investigated (Int. Cl. ⁷ , DB name) G08C 19/02 G01C 19/16 G01F 25/00 H04B 1/00 G06F 11/22 G06F 13/00

Claims (3)

(57) [Claims] 1. A signal from a measuring device is arithmetically processed and connected to an output signal line of a transmitter having a communication function of outputting a pulse signal having a weight of a measured amount, and a communication signal is superimposed on the output signal. By using a communication terminal device that performs communication by reading the measured amount, changing the specifications of the measuring device, adjusting and checking, and the like, in the communication method, after turning on the power to the transmitter, the pulse signal until a certain time. The communication is a communication waiting period for waiting for a communication signal from the communication terminal without outputting the communication terminal. When the communication signal from the communication terminal is not received within the communication waiting period, the transmitter outputs a pulse signal. Mode, when receiving a communication signal from the communication terminal within the communication waiting period, the transmitter can communicate with the communication terminal until the power of the transmitter is turned off. You Communication mode.
In the communication mode, a communication method between a transmitter for outputting a pulse signal and a communication terminal, wherein communication is prioritized without outputting the pulse signal even when a signal from the measuring device is input. . 2. A signal from a measuring device is arithmetically processed and connected to an output signal line of a transmitter having a communication function of outputting a pulse signal having a weight of a measured amount, and a communication signal is superimposed on the output signal. By using a communication terminal device that performs communication by reading the measured amount, changing the specifications of the measuring device, adjusting and checking, and the like, in the communication method, after turning on the power to the transmitter, the pulse signal until a certain time. The communication is a communication waiting period for waiting for a communication signal from the communication terminal without outputting the communication terminal. When the communication signal from the communication terminal is not received within the communication waiting period, the transmitter outputs a pulse signal. Mode, and when a communication signal from the communication terminal is received within the communication waiting period, the transmitter enables communication with the communication terminal until a predetermined time elapses after the end of communication. Communication mode.
In the communication mode, a communication method between a transmitter for outputting a pulse signal and a communication terminal, wherein communication is prioritized without outputting the pulse signal even when a signal from the measuring device is input. . 3. In the measurement mode, when the transmitter receives a communication signal from the communication terminal when there is no signal from the measurement device and the pulse signal is not output, the transmitter starts communication from the measurement mode. 3. A communication system between a transmitter for outputting a pulse signal and a communication terminal according to claim 1 or 2, wherein the mode is switched to a mode.