JPH0431158B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to remote monitoring and control of measuring instruments, servo amplifiers, etc. that input/output analog signals, and particularly relates to transmission lines such as optical fibers that transmit serial data. The invention relates to an analog signal input/output device provided between a monitor and a monitoring control target.

[Conventional technology]

Figure 5 shows a general remote monitoring and control system that monitors and controls measuring instruments, servo amplifiers, etc.
Upper controller 1 and multiple monitoring and control targets 2a,
2b,..., 2n are connected by a transmission line 3 made of optical fiber, and the monitoring and control targets 2a, 2
Interfaces 4a, 4b, as analog signal input/output devices are provided before and after b,...2n, respectively.
..., 4n are inserted.

Here, when the controller 1 transmits serial data via the transmission line 3, the interface 4
a, 4b, ..., 4n select the signals of their own stations, convert them into parallel data, and then convert them into analog signals and add them to the monitoring control targets 2a, 2b, ..., 2n, while also transmitting signals to these monitoring control objects. 2a, 2b,...,
The analog data outputted by 2n is digitized and converted into serial data, which is then sent back to the host controller 1 via the transmission line 3.

FIG. 6 is a block diagram showing the detailed configuration of the interface 4a, in which 41 is a central processing unit (hereinafter referred to as CPU), 42 is a memory, and 43 is a transmission line 3.
At the same time, the parallel data is converted to serial data and transferred to the transmission line 3.
44 is a DMA (Direct Memory Access) controller that transfers data using a vacant bus, 45 is a D/A converter, and 46 is an A/A converter.
D converters are shown respectively.

In FIG. 6, data sent from the transmission line 3 is received by a serial controller 43, and is sent to a memory 4 under the control of a DMA controller 44.
Transferred to 2. Next, this data is applied to the D/A converter 45 by the CPU 44, where it is converted into an analog signal and added to the monitoring control target. On the other hand, the analog signal from the monitoring control target is digitized by the A/D converter 46, and then temporarily stored in the memory 42 by the CPU 41. This data is also transferred to the serial controller 43 under the control of the DMA controller 44, where it is converted into serial data and sent out through the transmission line 3. These series of operations are performed under the control of the CPU 41 according to a predetermined procedure.

Note that the reason why the CPU 44 does not directly perform the input/output operation of data via the serial controller 43 but is controlled by the DMA controller 44 is that when inputting/outputting analog data at high speed with the host controller 1, the CPU 41 program This is because transmission and reception becomes impossible under control.

[Problem that the invention attempts to solve]

Although the conventional analog signal input/output device described above has few functions, it has many elements, namely,
The addition of the CPU 41, memory 42, and DMA controller 44 complicates the hardware configuration, increases the size, and reduces reliability accordingly.

The present invention was made in order to eliminate the drawbacks of such conventional devices, and its purpose is to provide an analog signal input/output device whose configuration can be significantly simplified, thereby achieving miniaturization and improved reliability. do.

[Means for solving problems]

The analog signal input/output device according to the present invention includes a receiving section that receives serial data and converts it into parallel data, a transmitting section that converts the parallel data into serial data and transmits it, and a coupling circuit that links these transmitting and receiving sections. a D/A converter that is directly connected to the serial signal control device and converts the parallel data of the receiving section into an analog signal; and a transmitting section that is also directly connected to the serial signal control device and converts the analog signal into a digital signal. It is equipped with an A/D converter in addition to the above.

[Effect]

In this invention, the serial data on the transmission line is received by the receiving section of the serial signal control device, the corresponding parallel data is added to the D/A converter, the analog signal is added to the monitoring control target, and the coupling circuit After a predetermined period of time has elapsed since the receiving operation, the analog signal from the monitoring control target is digitized by the A/D converter, and then converted into serial data by the transmitter of the serial signal control device and sent to the transmission line. .

〔Example〕

FIG. 1 is a block diagram showing the overall configuration of an embodiment of the present invention, in which a serial controller 43 as a serial signal control device is coupled to the transmission line 3.
Furthermore, the above-mentioned D/A converter 45 and A/D converter 46 are directly connected to this serial controller 43.

FIG. 2 is a block diagram showing the detailed configuration of the serial controller 43, which mainly receives data on the transmission line 31 and transfers the parallel data to the D/A converter 45.
A transmitter 410 added to the A/D converter 46
The transmitting section 420 converts the output of the converter into a serial signal and sends it out to the transmission line 32, and the delay circuit 430 as a coupling circuit is provided to proceed to the transmitting operation when the receiving section 410 performs the receiving operation.

The receiving section 410 also includes a demodulator 411 that divides frame-structured data from the transmission path 31 into data D1 and a clock K, a frame/address detection circuit 412 that detects the frame and its own address, and a frame/address detection circuit 412 that detects the frame and its own address. An AND gate 413 that sends a clock only when the address detection circuit detects the address of its own station, and this AND gate 41
Shift register 414 inputs data following the above address when clocked through 3.
and a bit number counter 415 that counts the clocks passing through the AND gate 413, and when this bit number counter 415 reaches a predetermined value, the contents of the shift register 414 are latched and the D/A converter 45
It consists of a latch 416 that feeds the

On the other hand, the transmitting section 420 includes an oscillator 421 that generates a clock, a bit number counter 422 that is reset by the output of the delay circuit 430 and counts the clock from that point on, and an oscillator 421 that responds to the bit number counter 422. An AND gate 423 that passes a clock, a shift register 424 that loads the output of the A/D converter 46 along with a synchronization frame code FLA and an address ADD of the host controller 1 (FIG. 5) according to a load signal from a delay circuit 430, and an AND gate. A modulator 42 synchronously modulates the contents of the shift register 424 in accordance with the clock of 423 and sends it out to the transmission path 32.
It consists of 5.

In the analog signal input/output device configured as described above, when synchronously modulated data is sent to the demodulator 411 via the transmission path 31, here,
The data is divided into data D1 and clock K and sent to frame/address detection circuit 412. This detection circuit detects the frame and the address of the own station's port, and when it matches the address of the own station, the AND gate 413
By opening the gate, subsequent data is input into the shift register 414. On the other hand, this data D1
The number of bits is counted by the bit number counter 415, and when all the data is taken into the shift register 414, the bit number counter 415 closes the latch 41.
6 is operated, and a completion report E is added to the frame/address detection circuit 412. The contents of latch 416 are thus converted to an analog signal by D/A converter 45, completing the receive cycle.

On the other hand, the conversion start command for the A/D converter is selected at an optimal time depending on the required conversion time, etc., but in this case, after the D/A converter receives the data, the data is It is becoming more and more popular. That is, the data of the A/D converter 46 is loaded into the shift register 424 along with the frame FLA for synchronization and the address ADD of the host controller 1 by the load signal L of the delay circuit 430. When the delay circuit 430 applies the load signal L to the shift register 424, the bit number counter 42 simultaneously
2, the clock K starts counting from that moment, and when the data has been loaded into the shift register 424, this clock K and the contents of the shift register 424 are input to the modulator 425. The signal is synchronously modulated here and then sent out to the transmission path 32. The transmission cycle is thus completed.

FIG. 3a shows the configuration of serial data sent through the transmission path 31, and FIG. 3b shows the configuration of the serial data sent out through the transmission path 32.
DataLink Control) format,
In addition, if necessary, CRC (Cyclic Redundancy)
Error detection may be performed by adding redundant bits for (Check).

Figures 4a to 4d are time charts showing examples of transmission procedures. When the upper controller 1 transmits data from each port at predetermined time intervals as shown in figure a, each port transmits data as shown in figure b. The D/A converter is operated from the moment the frame code/address is detected, and the data is obtained via the A/D converter 46 after the host controller has finished transmitting one frame of data, as shown in c in the same figure. At the same time, the A/D data is loaded from each port to the upper controller 1 as shown in d of the same figure.
Conversion data is sent.

In the above embodiment, a case has been described in which data transmission is performed by polling from a higher-level controller, but the present invention can also be applied to a call response method in which data transmission is started from each port.

By the way, although the present invention is for inputting and outputting analog signals from measuring instruments, servo amplifiers, etc., the serial signal control device 40 constituting the above embodiment is also capable of inputting and outputting contact signals. It can also be applied to remote sequence control by connecting.

〔Effect of the invention〕

As explained above, the present invention includes a serial signal control device comprising a receiving section, a transmitting section, and a coupling circuit that couples the two, a D/A converter that converts data from the receiving section into an analog signal and adds it to a monitoring control target. Since the main part consists of an A/D converter in addition to a transmitter that digitizes the analog signal output by the monitoring control target, the configuration is significantly simplified compared to conventional equipment that performs program processing. Therefore, it is possible to reduce the size and improve reliability, and furthermore, it is easy to make the entire device into a custom LSI.

[Brief explanation of drawings]

Fig. 1 is a block diagram showing the overall configuration of an embodiment of the present invention, Fig. 2 is a block diagram showing the detailed structure of the main elements of the embodiment, and Fig. 3 shows the operation of the embodiment. 4 is a time chart for explaining the operation of the same embodiment, FIG. 5 is a block diagram showing a general remote monitoring and control system, and FIG. 6 is a conventional analog signal input/output. FIG. 2 is a block diagram showing the configuration of the device. DESCRIPTION OF SYMBOLS 1... Upper controller, 2a, 2b...2n... Monitoring control object, 3... Transmission line, 43... Serial controller as a serial signal control device, 45... D/A
converter, 46...A/D converter, and the same reference numerals in each figure indicate the same or corresponding parts.

Claims (1)

[Claims] 1. A receiving unit that converts serial data from a transmission line into parallel data, a transmitting unit that converts parallel data into serial data and sends it to the transmission line, and after either one of these transmitting and receiving units completes its operation. A serial signal control device having a coupling circuit that couples the two so that the other starts operating after a predetermined time, and a D/A that converts the parallel data of the receiving section into an analog signal and adds it to the monitoring control target. a converter, and an A/D that converts the analog signal output by the monitoring control target into a digital signal and inputs the digital signal to the transmitter.
An analog signal input/output device characterized by comprising a converter.