SU1569580A1 - Arrangement for checking the dampening of scale - Google Patents

Abstract

The invention relates to a weight measuring technique, is intended for use in weighing devices, and allows for improved response speed. The device contains an analog-to-digital converter (ADC), registers, a code comparison circuit, a memory device, a three-port output I / O unit, a control circuit that signals a three-time interrogation of the ADC, registers. After the third poll, the ADC codes, registers are sent to the address bus of the storage device, a read operation is performed from the storage device, and the steady-state value of the load weight is output to the data bus of the latter. 2 Il.

Description

The invention relates to the field of weighing equipment and can be used in strain gauges and dispensers.

The purpose of the invention is to increase speed.

FIG. 1 is a functional diagram of the device for determining the steady-state value of the weight of the load; Fig. 2 shows a transient. The process and time points tt, t, t3 remove information.

A device for determining the steady-state weight of the load contains serially connected analog-to-digital converter (ADC) 1, registers 2 and 3, circuit 4 code comparison, the inputs of which are connected to the outputs of the ADC and registers 2 and 3. Synchronization of the device is from circuit 5 control .f

The device also contains a storage device 6, the address buses of which are connected to the outputs of the A / D converters 1 and registers 2 and 3, and the data bus - to the inputs of the comparator 7 and port A of the output three-port bidirectional input-output unit 8. Port B of I / O unit 8 is connected to the output of code comparison circuit 4, and port C is a device output for determining the steady-state value of the weight of the load.

The output of the comparator 7 is connected to the control input of the I / O unit 8 and controls its operation, and the output of the control circuit 5 is connected to the control inputs of the A / D converter 1, registers 2 and 3, 4 code comparison, I / O block 8, memory 6

SP

oh

09 SL

00

The device works as follows.

When the load is fed to the cargo device, the operation of the A / D converter 1 begins, which converts the analog signal corresponding to the weight of the load into a digital code. When reaching the output of the ADC 1 instantaneous value of the signal corresponding to the lower limit of the dose

weighed load, the load is loaded into the lifting device and the device starts to determine the steady state value of the load weight. The type of transient characteristic of the weight depends on the mechanical parameters of the load cell, the nature of the load, and the weight of the load.

Tensor mechanics with sufficient

2

3

accuracy can be described by a second order differential level.

For each sample of the weights, the mechanics parameters are practically unchanged, and the peculiarities of the weights loading are manifested -2 before the beginning of the period of calm, therefore, by the type of the initial section of the transient response, all its parameters can be predicted, including the established weight value. three parameters of the differential equation of the transient process, the combination of which is determined by the three different points of the transition characteristic

Having a table corresponding to the true value of the weight of the load at three points of the beginning of the transition process, it is possible to predict its termination at the beginning of the process, that is. true load weight. A correspondence table can be stored in a storage device of any kind. When using both a persistent storage device and a random access memory device, the size of the table is limited, and there is a possibility of a transient characteristic not considered in this table. In such cases, the determination of the steady-state weight of the cargo occurs upon completion of the transition process, and the information obtained can be used to expand the table stored in the memory device. When using a random access memory, it turns out to be completely absent. information, since in the course of the work it is completed

, 0

35

five

In this case, the performance of the weighing device in the initial period of operation is lower than that of the device with the table entered in advance, and later the performance of both devices are affected by the average performance of both devices, since the time required to fill the matching table , does not exceed 10-15% of the duration of the work shift0

The signals of the control circuit 5, synchronized with the device start-up time, sequentially triple ADC 1 at time t1, t2, t, respectively, with the first two values recorded in registers 2 and 3. After the third interrogation of ADC I on the address bus of the storage device 6 the code corresponding to the current value of the A / D converter I, registers 2 and 3 is sent, a read operation is performed from memory 6 at the given address, and the contents of the memory cell corresponding to this address are transmitted to the data bus properties 60

Thus, at each next weighing there is no delay in waiting for calm, and the initial three points of the transient process provide information on the steady-state weight, If even the memory 6 at the address indicated by the ADC I, registers 2 and 3, there is no information on earlier carried out a similar weighing, the device controls the progress of the weighing transient process and after its completion the weighing result is sent for further processing.

In the case of using random access memory 6, the result is used to supplement the correspondence table, i.e. in the process of operation, the device is adapted and the table of the correspondence of the parameters of the transition process to its initial three points is expanded. Assume that when you first turn on, all cells of random access memory 6 are written with zero. When first accessed, and if you access the address of random access memory 6, the memory cells of which are written with zeros, the Zero code is set on the data bus of random access memory 6 Ratio 7 and puts the I / O unit 8 into a state in which the code from port B passes to ports A and C. The random access memory 6 enters the write mode into the corresponding input code and, the apparatus waits for relieving strain gage full actuation circuit 4 and comparing the codes and then at port C input-output unit 8 is a code corresponding to the true weight of the load and the same code is recorded in the random access memory cell 6,

Claims (1)

Invention Formula A device for controlling the balance of the balance, containing serially connected analog-to-digital converter, registers, outputs of which are connected to the inputs of the code comparison circuit, while the control inputs are connected to the output of the control circuit, characterized in that, in order to improve speed, the output a three-port bidirectional I / O unit with a comparator on the control input; and Q memory device whose address bus is connected to the outputs of analog-digital converter and registers, data bus — to the first port of the output three-port bidirectional input-output unit, the first input of the comparator, the second input of which is connected to the body bus, the second port is connected to the code comparison output and control inputs 0 memory device and output three-port bidirectional I / O unit connected to the output of the control circuit ,, 1 Cargo weight , "J FIG. 2 lower dose limit