JPH0133053B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a retransmission pulse generator that scales an input pulse and then outputs it as a retransmission pulse.

<Prior Art> Generally, in a pulse generating flowmeter such as a turbine flowmeter, the number of pulses per unit volume of passing fluid is not a well-defined value such as 12.42 pulses per unit volume. For this reason, when calculating the integrated flow rate, the input pulses from the pulse emitting type flowmeter are scaled and converted into unit pulses, such as 10 pulses per pulse, and then retransmitted. In this case, conventionally the scaling constant K (for example 10/12.42) given the input pulse is
The data are thinned out to be as close to equal intervals (regular period) as possible according to the principles established for the data. For example, when 1000 input pulses are input, 805 retransmission pulses are output.

<Problems to be Solved by the Invention> However, in the conventional device, the signals are simply thinned out so that they are almost equally spaced, so when looking at the instant, the uniformity is weak, and the output ripple is large when input to the F/V converter. There was a problem in that it was not possible to directly obtain an analog 1 to 5V output, which was used for indicating meters, etc., through the F/V converter.

The present invention solves these problems,
It is an object of the present invention to provide a re-transmission pulse generator with excellent uniform spacing, which can directly obtain an analog 1 to 5 V output used for indicating a meter etc. through an F/V converter.

<Means for Solving the Problems> The present invention that achieves the above object includes an input counter that counts input pulses, a count value of this input counter that is read every measurement period, and calculations necessary for scaling performed. an arithmetic control means for determining the number and period of pulses to be retransmitted; an output counter for outputting retransmission pulses with a period set by the arithmetic control means; and the number of output pulses of the output counter and the arithmetic control means. Input the number of pulses to be set, and when the number of output pulses reaches the set number of pulses, stop the pulse output of the output counter, and
and a pulse number counter that outputs a signal indicating that the set number of pulse outputs of the arithmetic and control means have been completed.

Then, a retransmission pulse corresponding to the pulse input in the first measurement cycle is output from the output counter in the next measurement cycle, and the end of the next measurement cycle is notified to the calculation control means of the pulse number counter. It is characterized by being determined by the end signal.

<Function> Each component of the present invention has the following function. The calculation control means performs scaling calculation. Since the retransmission pulse generation circuit is configured using an output counter and a pulse number counter, the retransmission pulse output period will be delayed compared to the input pulse measurement period, but within the output period, Since the pulse period is held constant, the output ripple is reduced.

<Example> The present invention will be explained below using the drawings.

FIG. 1 is a connection diagram showing one embodiment of the present invention. In the figure, 1 is an input counter that counts input pulses P _i from a pulse emitting type flow meter (not shown), etc., and 2 is a processor used as an arithmetic control means.
It is used to read data via the oscilloscope, perform calculations necessary for scaling, and set the number and period of pulses to be retransmitted. Usually, the scaling constant C is in the range of 0 to 1, but it may be set to 1 or more. The following relationship exists between the input pulse P _i and the output pulse number Po.

P _i xC=Po (1) 3 is the re-transmission pulse generation circuit, and the output counter 3
1 and a pulse number counter 32, and a processor 2
A set number of re-transmission pulses Po having a set period are outputted from the data bus 4 via the data bus 4. The output counter 31 divides the clock pulse Pc applied to the clock input CLK by the period Tc set by the processor 2 and outputs a retransmission pulse Po to the output terminal OUT. It is prohibited by becoming “L”. Note that the clock pulse Pc is selected to have a sufficiently high frequency compared to the retransmitted pulse Po.
The pulse number counter 32 is connected to the output counter 3 which is added to the clock output CLK via the NOR gate NOR.
The number of re-transmission pulses Po from 1 is counted, and when the number set by processor 2 is reached, the output terminal
out to "H" level, closes the gate GATE of the output counter 31 via the inverter IV ₁ , and prohibits the re-transmission of the pulse Po. At the same time, an interrupt is applied to the processor 2, and the set number of pulses Po is output. This is to notify you that the output has finished. The pulse number counter 32 is a gate input
Trigger pulse Pt applied to GATE via inverter IV ₂ and NOR gate applied to clock input CLK
Dummy clock Pd is connected to processor 2 via NOR.
When it is added from , it is ready to start counting.

The operation of the device configured in this manner will be described next. FIG. 2 is a time chart explaining the operation of the apparatus shown in FIG. 1, and FIG. 3 is a flow chart. First, processor 2 outputs the retransmission pulse Po that it wants to output.
The period To of the clock pulse Pc is set in the output counter 31 as a frequency division ratio m (=To/Tc) according to the period Tc of the clock pulse Pc. The next retransmission pulse you want to output
The number No of Po is set in the pulse number counter 32.
Then, when the processor 2 outputs the trigger pulse Pt and the dummy clock Pd in this order, the pulse number counter 32 enters the counting start state, the output of the pulse number counter 32 becomes "L", and the output counter 31
Open the gate and start outputting the output pulse Po. The pulse number counter 32 decrements a preset number by 1 each time the output pulse Po rises, and when the value reaches zero, the output is set to "H" and the gate of the output counter 31 is closed. At the same time, the output becomes an interrupt for processor 2, so it changes from “L” to “H”
When the number changes, an interrupt is sent to the processor 2 to notify that the output of the set number of pulses Po has ended.

The processor 2 reads the count value of the input counter 1, performs scaling, and sets the number and cycle of the next retransmission pulses in the output counter 31 and pulse number counter 32 of the retransmission pulse generation circuit 3,
The retransmission pulse Po continues to be generated while continuously changing the pulse period using the same procedure.

<Effects of the Invention> As explained above, the present invention has the following effects.

Since the period of the retransmission pulse Po is determined by scaling in the processor 2, the periodicity of the retransmission pulse Po is superior to that of conventional thinning.

Although the retransmission pulse is delayed by one measurement cycle compared to the input pulse, high real-time performance can be achieved by making the interrupt cycle faster as necessary.

Even when the number of input pulses changes suddenly, the processor 2 can shorten the interrupt cycle to easily follow the re-transmitted pulses.

[Brief explanation of drawings]

Figure 1 is a connection diagram showing one embodiment of the present invention, Figure 2 is a connection diagram showing an embodiment of the present invention.
The figure is a time chart explaining the operation of the apparatus shown in FIG. 1, and FIG. 3 is a flow chart. DESCRIPTION OF SYMBOLS 1...Input counter, 2...Arithmetic control means (processor), 3...Retransmission pulse generation circuit, 31
... Output counter, 32 ... Pulse number counter,
4...Data bus.

Claims (1)

[Claims] 1. An input counter that counts input pulses, and arithmetic control that reads the count value of this input counter every measurement cycle, performs calculations necessary for scaling, and determines the number and period of pulses to be retransmitted. an output counter that outputs retransmission pulses with a period set by the arithmetic control means; and an output counter that outputs the number of output pulses of the output counter and the number of pulses set by the arithmetic control means; a pulse number counter that stops the pulse output of the output counter when reaches a set number of pulses, and outputs a signal to the arithmetic control means notifying that the set number of pulse outputs has been completed; A retransmission pulse corresponding to the pulse inputted in is outputted from the output counter in the next measurement cycle, and the end of the next measurement cycle is determined by an end signal of the pulse number counter to the calculation control means. Characteristic re-transmission pulse generator.