CN1083572C - Process control machine pulsed insertion plate - Google Patents

Abstract

The present invention relates to a pulsed insertion board of an industrial control computer. A pulsed insertion technique is used in the board, and the present invention is composed of a starting and stopping signal input processing circuit, a pulse signal input processing circuit, a logical operation circuit, a T2 gate control electric level output circuit and a T1 gate control electric level output circuit. The insertion board, a flow rate detection device and a pulse counting card of the industrial control computer work together to enhance the effective bit number of the accumulated pulse number of a flow meter. Consequently, the detection precision of the flow meter is enhanced.

Description

Process control machine pulsed insertion plate

The utility model relates to a kind of pulse insertion technology, is applied on the flow instrument calibrating installation, improves the calibration accuracy of instrument and the automatization level of verification process.

Need improve the resolution of step-by-step counting in many applications, when having a certain specific flowmeter of pulse output signals with standard pipe prover calibrating, (because the umber of pulse that flowmeter per unit volume output quantity can produce is limited) that the umber of pulse of collecting during the calibrating is always limited.Counter under the normal condition can only be realized the accumulative total of whole pulse number, and cumulative errors are positive and negative 1 pulse, if the umber of pulse of accumulative total is fewer, this error can produce very big influence to the precision of system.Therefore, must increase the number of significant digit of umber of pulse in this case.At present, the main whole pulse counter that adopts carries out pulse accumulative total, not only precision is low, and this counter can't be realized the automatic collection of umber of pulse and the automatic control of verification process, so the scene mostly adopts artificial method to examine and determine, so not only speed is slow, low precision, efficient is low, but also brings personal error easily.

Fundamental purpose of the present invention is to propose a kind of process control machine pulsed insertion plate, is loaded on the flow instrument calibrating installation, by this plate and flow instrument calibrating installation and industrial computer collaborative work, realizes the high-precision measuring of umber of pulse.Thereby improve the automatization level of flow instrument calibration accuracy and verification process.

Major technique content of the present invention is, this process control machine pulsed insertion plate implementation method is to have adopted pulse insertion technology, its principle is collected in the complete umber of pulse that calibrating run duration flowmeter sends with a counter as shown in Figure 1, measures two time intervals simultaneously.

T ₁Be first flowmeter pulse of tracking detecting device enabling signal, and the time interval between first flowmeter pulse of tracking detecting device stop signal.

T ₂Be the time interval between detecting device startup and the stop signal.

N start by the front and back detecting device and stop signal between the whole pulse number of accumulative total.

N ' is the umber of pulse of actual accumulative total.

As can be seen, T ₁For in fact adding up n the time that the whole pulse number is used,, can pass through T so if pulse is even (being constant period) ₁/ n obtains the width of individual pulse, uses T again ₂Remove and just can obtain at T ₂The actual umber of pulse that should add up in time period.Actual accumulative total umber of pulse n ' is calculated by following formula: $n^{\&prime;}=n\frac{T_2}{{\mathrm{<figure-callout\; id="1"\; label="T"\; filenames="C9811418100141.png"\; state="\{\{state\}\}">T</figure-callout>}}_1}$

Its structure as shown in Figure 2, by start stop signal input processing circuit, pulse signal input processing circuit, logical operation circuit, T ₁Gate electrical level output circuit, T ₂The gate electrical level output circuit constitutes.

The start stop signal input processing circuit is made of overvoltage negative pressure holding circuit 3, de-twitter circuit 5, signal amplification change-over circuit 6, photoelectric isolating circuit 8, pulse shaping amplification circuit 10, jumper switch 12, pulse-level shifting circuit 13.The signal 1 that is come by the calibrating installation start stop switch enters current limliting, the amplitude limiting processing that overvoltage negative pressure holding circuit 3 is carried out signal, and overvoltage negative pressure holding circuit is by adjustable resistance VR ₁, the 16th resistance R ₁₆, the 19th resistance R ₁₉With the 3rd diode D ₃, the 4th diode D ₄, the 2nd diode D ₂Constitute the 3rd diode D ₃, the 4th diode D ₄Play clamping action, the 2nd diode D ₂Play the negative pressure protective effect, the 16th resistance R ₁₆, the 19th resistance R ₁₉Play metering function, the 1st adjustable resistance VR ₁Be variable resistor, by regulating the 1st adjustable resistance VR ₁Adjustable threshold voltage makes this input circuit can adapt to very wide input voltage range.The output of overvoltage negative pressure holding circuit 3 connects de-twitter circuit 5, and de-twitter circuit 5 is by the 1st electrochemical capacitor E ₁Constitute, but the clutter in the filtering start stop signal prevents the misoperation of back circuit.The output of de-twitter circuit 5 connects signal and amplifies change-over circuit 6, and signal amplifies change-over circuit 6 by the 3rd triode N ₃9013 constitute, and the signal output after the amplification connects photoelectric isolating circuit 8, and photoelectric isolating circuit 8 is by the 1st photoelectrical coupler O ₁4N27 and the 1st resistance R ₁Constitute, its effect is that outer signals and industrial computer equipment are isolated fully, fundamentally suppresses the extraneous interference signal, and the output signal of photoelectric isolating circuit 8 enters pulse shaping circuit 10, and pulse shaping circuit 10 is by resistance the 4th resistance R ₄, the 22nd resistance R ₂₂, the 25th resistance R ₂₅, the 1st triode N ₁9013, Schmidt trigger U1:O 74LS14 constitutes, will be by the 1st photoisolator O ₁Start stop signal convert the TTL logic level to, the output pin 8 of Schmidt trigger U1:0 connects the pin one that jumper switch 12 is SC9, SC9 can be set as pin one and pin two short circuit or pin 3 and pin two short circuit by short-circuit block, if start stop signal is level type (level is a steady state value in promptly between the count block), with pin one and the pin two short circuit of short-circuit block with SC9, directly input arithmetic logic circuit and T of start stop signal at this moment ₂The gate electrical level output circuit.If start stop signal is impulse type (level is two spikes in promptly between the count block), then with the pin 3 and pin two short circuit of short-circuit block with SC9, at this moment the start stop signal of impulse type is introduced into pulse-level shifting circuit 13, outputs to logical operation circuit and T by pulse-level shifting circuit 13 again after converting pulse signal to level signal ₂The gate electrical level output circuit, pulse-level shifting circuit 13 is by JK flip-flop U2:A 74LS109A and the 3rd resistance R ₃Form, constitute bistable circuit.

The pulse signal treatment circuit is made up of overvoltage negative pressure holding circuit 4, signal amplification change-over circuit 7, photoelectric isolating circuit 9, pulse shaping amplification circuit 11, and overvoltage negative pressure holding circuit 4 is by the 2nd adjustable resistance VR ₂, the 17th resistance R ₁₇, the 5th resistance R ₅With the 6th diode D ₆, the 7th diode D ₇With the 5th diode D ₅Form, the pulse signal 2 that comes from flowmeter enters current limliting, the amplitude limiting processing that overvoltage negative pressure holding circuit is carried out signal, the 6th diode D ₆, the 7th diode D ₇Play clamping action, the 5th diode D ₅Play the negative pressure protective effect, the 17th resistance R ₁₇, the 5th resistance R ₅Play metering function, the 2nd adjustable resistance VR ₂Be variable resistor, by regulating the 2nd adjustable resistance VR ₂Adjustable threshold voltage makes this input circuit can adapt to very wide input voltage range.The output of overvoltage negative pressure holding circuit 4 connects signal and amplifies change-over circuit 7, and signal amplifies change-over circuit 7 by the 4th triode N ₄9013 constitute, and the signal output after the amplification connects photoelectric isolating circuit 9, and photoelectric isolating circuit 9 is by the 2nd photoelectrical coupler O ₂4N27 and the 20th resistance R ₂₀Constitute, its effect is that outer signals and industrial computer equipment are isolated fully, fundamentally suppresses the extraneous interference signal.The output signal of photoelectric isolating circuit 9 enters pulse shaping amplification circuit 11, and pulse shaping amplification circuit 11 is by the 8th resistance R ₈, the 23rd resistance R ₂₃, the 26th resistance R ₂₆And the 2nd triode N ₂9013, Schmidt trigger U1:E 74LS14 constitutes, will be by the 2nd photoisolator O ₂Pulse signal convert the TTL logic level to, this signal outputs to logical operation circuit and pulse signal output circuit by jumper switch SC13.SC13 is a jumper switch, and the effect of this switch is that pulse signal both can be come from the outside, again can be from process control machine pulsed numbered card itself, so that debugging.

Logical operation circuit is by OR circuit 16, NOR gate circuit 14 and JK flip-flop circuit 15 constitute, the effect of OR circuit 16 is to make the start and stop control signal not only can come from external unit but also can come from industrial computer itself, OR circuit 16 by or a door integrated circuit U3:A74LS32 constituted, the switching value output signal 1 that its pin one connects the industrial computer numbered card is D01, pin two connects the output terminal of start stop signal treatment circuit, because the switching value output signal of industrial computer numbered card can put 1 or clear 0 by software, therefore available software is controlled process control machine pulsed insertion plate and is counted, if want to control process control machine pulsed insertion plate with the start stop signal of external unit, then must be with the switching value output signal D01 of process control machine pulsed numbered card clear 0 (preventing the locked OR circuit 16 of D01).The effect of NOR gate circuit 14 is to judge whether the output of OR circuit is identical with the output of JK flip-flop circuit 15, open or locked JK flip-flop circuit 15, NOR gate circuit 14 is made of XOR gate integrated circuit U4:A 74LS86, its pin one connects the pin one 2 (the network label is TIG) of JK flip-flop U2:B 74LS109A, pin two connects 3 pin (the network label is SYTT) of OR circuit U3:A 74LS32, signal as TIG and SYTT is all high level or is all low level, XOR gate U4:A 74LS86 output low level then, JK flip-flop U2:B 74LS109A is locked, prevent that it from overturning under the pulse action that acts on pin one 0, different as TIG with the signal level of SYTT, then XOR gate U4:A 74LS86 exports high level, JK flip-flop U2:B 74LS109A is opened, and U2:B 74LS109A overturns in the time of just can arriving at the rising edge of the pulse that acts on pin one 0.JK flip-flop circuit 15 is made of JK flip-flop U2:B 74LS109A and U1:A 74LS14, the effect of U1:A 74LS14 is to make the level of 13 pin of U2:B 74LS109A and 14 pins opposite, U2:B 74LS109A is barricaded as JK flip-flop, U2:B 74LS109A is opened during for high level at the pin 4 of U4:A 74LS86, locked during low level, the logical operation by NOR gate circuit 14 and JK flip-flop 15 can obtain T ₁The gate level (be the T among Fig. 1 ₁Time period) TIG, SYTT then are T ₂The gate level (be the T among Fig. 1 ₂Time period), TIG outputs to T ₁The gate electrical level output circuit, SYTT outputs to T ₂The gate electrical level output circuit, (4) pin of U2:A links to each other with 15 pin of U2:B, and links to each other with process control machine pulsed numbered card, can carry out clear operation by the output switching terminal mouth D01 of process control machine pulsed numbered card.Its logical operation process as shown in Figure 1, initial period SYTT and TIG are low level, when start stop signal SYTT becomes high level, the level of XOR gate U4:A 74LS86 pin one and pin two is opposite, at this moment its pin 3 is exported high level, JK flip-flop U2:B 74LS109A is opened, and the rising edge that JK flip-flop U2:B 74LS109A will be applied the impulse level on pin one 0 triggers upset, T like this ₁Just can follow the tracks of first flowmeter pulse of detecting device enabling signal; After JK flip-flop U2:B 74LS109A overturns, TIG becomes high level, this moment, SYTT also was a high level, the level of XOR gate U4:A 74LS86 pin one and pin two is identical, at this moment pin 3 output low levels of U4:A 74LS86 are locked with JK flip-flop U2:B 74LS109A, even even on the pin one 0 of JK flip-flop U2:B 74LS109A flowmeter pulse input is arranged at this moment, JK flip-flop can not overturn yet, and it is constant that TIG keeps high level.When TIG becomes low level again, the level of XOR gate U4:A 74LS86 pin one and pin two is opposite, at this moment XOR gate U4:A 74LS86 pin 3 is exported high level, JK flip-flop U2:B 74LS109A is opened, the rising edge that JK flip-flop U2:B 74LS109A will be applied the impulse level on pin one 0 triggers upset, T like this ₁Just can follow the tracks of first flow pulse of detecting device stop signal, just can obtain T ₁The time interval.

T ₁The gate electrical level output circuit is by jumper switch 18, negative circuit 21, and T ₁24 formations of gate level output end, jumper switch 18 is the SC11 in the circuit diagram, can make 1 and 2 short circuits or 3 and 2 short circuits by short-circuit block, negative circuit 21 is by Schmidt trigger U1:C 74LS14 and pull-up resistor the 9th resistance R ₉Constitute, be used for signal inversion with TIG, 2 pin of jumper switch 18 (network number is TIGATE) directly and gate level T ₁Lead-out terminal 24 links to each other, if with 1 and 2 short-circuits of terminals of short-circuit block with SC11, then the TIG signal just directly outputs to terminal 24, if with 3 and the 2 pin short circuits of SC11, then TIG is with regard to the first terminal 24 that outputs to again after U1:C 74LS14 is anti-phase.

T ₂The gate electrical level output circuit is by jumper switch 20, negative circuit 23 and T ₂26 formations of gate level output end, jumper switch 20 is the SC10 in the circuit diagram, and available short-circuit block makes 1 and 2 short circuits or 3 and 2 short circuits, and negative circuit 23 is by Schmidt trigger U1:B 74LS14 and pull-up resistor the 11st resistance R ₁₁, the 7th resistance R ₇Constitute, be used for signal inversion with SYTT, 2 pin of jumper switch 20 (network number is TGATE) directly and gate level T ₂Lead-out terminal 26 links to each other, if with 1 and 2 short-circuits of terminals of short-circuit block with SC10, then the SYTT signal just directly outputs to terminal 26, if with 3 and 2 short-circuits of terminals of SC10, then the SYTT signal is with regard to the first terminal 26 that outputs to again after U1:B74LS14 is anti-phase.

2 pin that pulse signal directly leads to jumper switch 17 SC13 link to each other with pulse signal output end 25.

The principle of work of process control machine pulsed insertion plate as shown in Figure 3, at first with the gate terminals and the T of the terminal 24 of process control machine pulsed insertion plate and the impulse meter of process control machine pulsed numbered card (be used for accumulative total umber of pulse n) ₂Timer (is used for determining time T ₂) gate terminals link to each other, the counting end (being the CLK end) of the impulse meter of process control machine pulsed numbered card (accumulative total umber of pulse n) links to each other the T of process control machine pulsed numbered card with the terminal 25 of process control machine pulsed insertion plate ₂The counting end of timer (CLK end) links to each other with the clock-signal generator of process control machine pulsed numbered card, again with the terminal 26 of process control machine pulsed insertion plate and the T of process control machine pulsed numbered card ₁The gate terminals of timer links to each other, and the counting end of numbered card (CLK end) links to each other with the clock-signal generator of numbered card.Like this, the pulse n counter and the T of process control machine pulsed numbered card ₂Timer will be counted when terminal 24 output levels are high (or low) and regularly, stop counting and timing when terminal 24 output levels are low (or high), so just can count n and T by industrial computer software read pulse ₂Value, T ₁Timer will carry out timing when terminal 26 output levels are high (or low), stop regularly so just can reading T by industrial computer software when 26 of terminal is output as low (or high) ₁Time value is obtained the actual pulse number by software again.

Technique effect of the present invention is this process control machine pulsed insertion plate and flow calibrating installation and process control machine pulsed numbered card collaborative work, can improve the number of significant digit of flowmeter accumulative total umber of pulse, thereby improve the meter proof precision, if the umber of pulse of accumulative total is less than 1000, with former flowmeter counting apparatus measure can only have 3 significant figure, the precision of pulse accumulative total is less than 1 ‰, add this pulse insert plate after number of significant digit can reach 6, the precision of pulse accumulative total can reach 1,000,000/.And the few more raising precision of umber of pulse effect is obvious more.

Fig. 1 is a technical schematic diagram of the present invention;

Fig. 2 is a block diagram of the present invention;

Fig. 3 is circuit theory diagrams of the present invention;

Fig. 4 is a using method connection layout of the present invention.

T ₁Be the time interval between first flowmeter pulse of first flow pulse of following the tracks of the detecting device enabling signal and tracking detecting device stop signal, T ₂Be the time interval between detecting device startup and the stop signal; the whole pulse number that is added up between detecting device startup and the stop signal before and after the n; 1 calibrating installation start stop switch signal; 2 flowmeter pulse signals; 3,4 overvoltage negative pressure holding circuits, 5 de-twitter circuits, 6,7 signals amplify change-over circuit; 8,9 photoelectric isolating circuits; 10,11 pulse shaping amplification circuits, 12,17,18,20 jumper switchs, 13 pulses-level shifting circuit; 14 NOR gate circuits; the 15JK flip-flop circuit, 16 OR circuit, 17 jumper switchs; 21,23 negative circuits, 24T ₁Gate level output end, 25 treated Transistor-Transistor Logic level pulse signal output end, 26 T ₂Gate level output end, A industrial computer, B process control machine pulsed insertion plate, the process control machine pulsed numbered card of C.

Realize embodiments of the invention as shown in the figure.

This process control machine pulsed insertion plate is to be loaded on the flow instrument calibrating installation, by this plate and flow instrument calibrating installation and process control machine pulsed numbered card collaborative work, realizes the high-precision measuring of umber of pulse, as shown in Figure 4.

Claims (1)

1, process control machine pulsed insertion plate is characterized in that this plate is to have adopted pulse insertion technology, is collected in the whole umber of pulse that calibrating run duration flowmeter sends with a counter, measures two time intervals simultaneously, that is:

T ₁Be first flowmeter pulse of tracking detecting device enabling signal, and the time interval between first flowmeter pulse of tracking detecting device stop signal;

T ₂Be the time interval between detecting device startup and the stop signal;

N start by the front and back detecting device and stop signal between the whole pulse number of accumulative total;

N ' is the umber of pulse of actual accumulative total.

T ₁For in fact adding up n the time that the whole pulse number is used, can pass through T ₁/ n obtains the width of individual pulse, uses T again ₂Remove and just can obtain at T ₂The actual umber of pulse that should add up in time period, actual accumulative total umber of pulse n ' is calculated by following formula: $n^{\&prime;}=n\frac{T_2}{T_1}$

Its structure is by start stop signal input processing circuit, pulse signal input processing circuit, logical operation circuit, T ₁Gate electrical level output circuit, T ₂The gate electrical level output circuit constitutes;

The start stop signal input processing circuit is made of overvoltage negative pressure holding circuit (3), de-twitter circuit (5), signal amplification change-over circuit (6), photoelectric isolating circuit (8), pulse shaping amplification circuit (10), jumper switch (12), pulse-level shifting circuit (13); The signal (1) that is come by start stop switch enters overvoltage negative pressure holding circuit (3), and overvoltage negative pressure holding circuit is by adjustable resistance (VR ₁), the 16th resistance (R ₁₆), the 19th resistance (R ₁₉) and the 3rd diode (D ₃), the 4th diode (D ₄), the 2nd diode (D ₂) constitute, its output connects de-twitter circuit (5); De-twitter circuit (5) is by the 1st electrochemical capacitor (E ₁) constitute, its output connects signal and amplifies change-over circuit (6); Signal amplifies change-over circuit (6) by the 3rd triode (N ₃) constitute, its output connects photoelectric isolating circuit (8), and photoelectric isolating circuit (8) is by the 1st photoelectrical coupler (O ₁) and the 1st resistance (R ₁) constitute, being used for suppressing the extraneous interference signal, its output signal enters pulse shaping circuit (10); Pulse shaping circuit (10) is by resistance the 4th resistance (R ₄), the 22nd resistance (R ₂₂), the 25th resistance (R ₂₅), the 1st triode (N ₁), Schmidt trigger (U1:O) constitutes, and converts start stop signal to the TTL logic level, by jumper switch (12) directly input arithmetic logic circuit and T ₂The gate electrical level output circuit, or send into pulse-level shifting circuit (13) by jumper switch (12), pulse-level shifting circuit (13) is by JK flip-flop (U2:A) and the 3rd resistance (R ₃) form, constitute bistable circuit, convert pulse signal to level signal, its output connects logical operation circuit by jumper switch (12);

The pulse signal treatment circuit is made up of overvoltage negative pressure holding circuit (4), signal amplification change-over circuit (7), photoelectric isolating circuit (9), pulse shaping amplification circuit (11); The pulse signal of being sent here by flowmeter (2) enters overvoltage negative pressure holding circuit (4); Overvoltage negative pressure holding circuit (4) is by adjustable resistance (VR ₂), the 17th resistance (R ₁₇), the 5th resistance (R ₅) and the 6th diode (D ₆), the 7th diode (D ₇), the 5th diode (D ₅) constitute, its output connects signal and amplifies change-over circuit (7), and signal amplifies change-over circuit (7) by the 4th triode (N ₄) constitute, its output connects photoelectric isolating circuit (9); Photoelectric isolating circuit (9) is by the 2nd photoelectrical coupler (O ₂) and the 20th resistance (R ₂₀) constitute, being used for suppressing the extraneous interference signal, its output signal enters pulse shaping amplification circuit (11), and pulse shaping amplification circuit (11) is by the 8th resistance (R ₈), the 23rd resistance (R ₂₃), the 26th resistance (R ₂₆) and the 2nd triode (N ₂), Schmidt trigger (U1:E) constitutes, and converts pulse signal to the TTL logic level, its output outputs to logical operation circuit by jumper switch 17;

Logical operation circuit is made of OR circuit (16), NOR gate circuit (14) and JK flip-flop circuit (15), the source that is used to select the start and stop control signal of OR circuit (16), by or a door integrated circuit (U3:A) constitute, the switching value output signal (1) i.e. that its input pin connects the industrial computer numbered card is (D01), another input pin connects the output terminal of start stop signal treatment circuit, and output pin connects NOR gate circuit (14); NOR gate circuit (14) is made of XOR gate integrated circuit (U4:A), is used to judge whether T1, T2 gate level are homophase, and its output pin connects the upset of JK flip-flop (15) control JK flip-flop; JK flip-flop circuit (15) constitutes by JK flip-flop (U2:B) with (U1:A), and (4) pin (U2:A) links to each other with (15) pin of (U2:B), and links to each other with process control machine pulsed numbered card;

T ₁The gate electrical level output circuit is by jumper switch (18), negative circuit (21), and T ₁Gate level output end (24) constitutes, and negative circuit (21) is by Schmidt trigger (U1:C) and pull-up resistor the 9th resistance (R ₉) constitute, the just anti-phase pin of Schmidt trigger (U1:C) respectively with link to each other with (1), (3) pin of jumper switch 18, (2) pin of jumper switch 18 links to each other with the gate terminals of process control machine pulsed numbered card;

T ₂The gate electrical level output circuit is by jumper switch (20), negative circuit (23) and T ₂Gate level output end (26) constitutes, and negative circuit (23) is by Schmidt trigger (U1:B) and pull-up resistor the 11st resistance (R ₁₁), the 7th resistance (R ₇) constitute, (2) pin of jumper switch (20) is directly and gate level (T ₂) lead-out terminal (26) links to each other.

This plate is loaded on the flow instrument calibrating installation, by this plate and flow instrument calibrating installation and process control machine pulsed numbered card collaborative work, realizes the high-precision measuring of umber of pulse.

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