JPS63273102A - Remote input and output controller - Google Patents

Abstract

PURPOSE:To safely control the device by receiving a signal representing whether or not power supply of an input/output module is normal and applying properly the processing of an input signal and an output signal in response to said signal. CONSTITUTION:When a voltage is impressed to an input terminal 41, a photocoupler 40 is turned off and it is judged that an external input is in error, the setting of a dip switch 39 setting how to process the output data is read via an interface 38. For example, when output data are all canceled, an output off-flag 34 is set and when the output data are left ad they are, an output storage flag 35 is ON. How to process the input data is judge next and when the transfer of input is, for example, stopped, an output buffer 33 is cleared to reset the output-off flag 34 (S20) if said flag 34 is ON and the content of the output buffer 33 is sent to the output terminal of the input/output module 21. Thus, a fault of an external power supply or the like is detected to control the transmission/reception with a master set.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a programmable controller, and particularly to transmission and reception between a remote input/output controller and a master unit thereof.

(Prior art and problems to be solved by the invention) Part 3
The figure is a block diagram showing the entire master station and remote station of a conventional programmable controller. In the figure,
10 is a programmable controller that serves as the main unit, and 11
1 is its input/output module, -12 is a remote input/output interface, 13 is a CPU, and 14 is a power supply. 20
is the remote input/output internal station, 21 is its input/output module,
22 is a remote input/output controller, and 23 is its power supply.

The conventional programmable controller is configured as described above, and transmits and receives data between the base unit 10 and the remote input/output station 20. At this time, the remote input/output internal station 20 checks the status of its own power supply 23, and if it is normal, serial communication of input/output data is performed. However, it is not possible to identify incorrect input/output data due to a failure of the external load power supply, etc. by only checking the power supply of the own station.

For example, as shown in FIG.
During the period o, malfunctions are likely to occur.

In the main unit 10, a signal that indicates whether the external power supply is normal or not is connected to the input terminal 1:', and the user software can perform safety processing in the event of an external abnormality. There is a problem in that even if a signal indicating an external state is inputted, processing is impossible.

The present invention has been made to solve these problems, and an object of the present invention is to provide a remote input/output controller having an additional function of checking the external status of the remote input/output internal station, including the external power source.

(Means for Solving the Problems) A remote input/output controller according to the present invention includes an input means for inputting a signal detected as to whether the input is in a normal state, and an input from the means and a predetermined setting. It has a control means for controlling output information from the parent device and input information to the parent device based on a command.

(Function) In the present invention, if there is an abnormality in the external power supply or the like, it is detected and transmission and reception with the base unit is controlled.

(Embodiment) FIG. 1 is a diagram showing an embodiment of the present invention, in which 30 is a serial interface, 31 is a human output control interface, 32 is an input buffer, 33 is an output buffer, 34 is an output off flag, and 35 is an output. retention flag,
36 is a RAM.

The output off flag 34 and output hold flag 35 are set to R for convenience.
Although shown separately from the AM 36, it is actually formed as a part of the RAM 36.

37 is a ROM in which programs are stored.

38 is an interface, 39 is a dip switch,
Used to set the processing method for output data and input data in abnormal conditions. 40 is a photocoupler, and the photodiodes on the input side are connected in parallel in opposite directions so that both alternating current and direct current can be used as input signals. 41 is an input terminal. 42 is the CPU, ROM
Predetermined calculations are performed according to the program stored in 37.

The remote input/output controller configured as described above performs predetermined calculation operations as shown in the flowchart of FIG. In other words, the remote input/output controller judges whether the power supply applied to itself (see reference numeral 23 in Figure 3) is normally supplying voltage (Sl), and if it is judged to be normal, then the external It is determined whether the state of the power supply, etc. is normal (S2). This determination is made depending on the presence or absence of input from the photocoupler 40.

For example, during normal operation, a voltage is applied to the input terminal 41, the photocoupler 40 is turned on, and the signal is taken in. If it is determined to be normal, the output off flag 34 and output hold flag 35 are reset and turned off (S3).
. Furthermore, input data is taken in from the input/output module 21 via the input/output control interface 31 (
S4), input cover 32. (S5).

Next, it is determined whether there is an instruction from the parent device (see reference numeral 10 in FIG. 3) (S6), and if there is an instruction, it is determined whether the output off flag 34 is on (S7). Since the output off flag 34 is off here, it is next determined whether the output holding flag 34 is on (S8).

Here it is turned off as well, so next,
The output data is taken in via the serial interface 30 (S9) and stored in the output buffer 33 (S
10). The input data stored in the input buffer 32 is sent to the remote human output interface 12 of the base unit 10 via the serial interface 30 (S
12). Base unit 10 performs a predetermined calculation based on the input to obtain data to be sent to a remote incoming/output station, etc.

Further, the output data stored in the output buffer 35 is sent to the output terminal of the input/output module 21 via the input/output control interface 31 (S13),
A control signal is sent to an external device (not shown). The above operations are repeated until an end command is issued (S14).

The above series of operations is the operation when the external input is determined to be normal in step S2, but if it is determined to be abnormal, it is determined how to process the output data. (S15).

This determination is made by reading the settings of the dip switch 39 via the interface 38.

Here, for example, there are cases in which all output data is turned off and cases in which it is left as is (previous data), and when all output data is turned off, processing is performed to turn on the output off flag 34 (S15). If the output data is to be left as is, the output holding flag 35 is turned on (S17). Next, determine how to process the input data (818)
.

Here, it is assumed that there are three cases, for example, when the transfer of input data is stopped, when the input data is reset to zero, and when the previous input data is sent again. When it is determined that the transfer of input data is to be stopped, it is then determined whether the output off flag 34 is turned on or not.
9), when it is on, clear the output buffer 33 and turn it off 520), and send the contents of the output buffer 33 to the output terminal of the people output module 21 via the input/output control interface 31 (S 1
3).

When the output off flag 34 is off, it is determined whether the output hold flag 35 is on or not (521).
, when it is off, the process returns to the first step (Sl) without performing any processing. When the output off flag 34 is on, the previous data can be output as is, so the contents of the output buffer 33 at that time are sent to the output terminal of the input/output module 21 via the input/output control interface 31. (S13).

Furthermore, when it is determined that the input data is to be reset to zero (S18), the input buffer 32 is reset (S18).
22). After this reset process and step 8
After it is determined in step S18 that the previous input data is to be sent as is, the process returns to step S6 and waits for an instruction from the base unit 10. In these two cases, when the output off flag 34 is off, the output buffer 33 is cleared (S11), and when the output hold flag 35 is on, the output buffer 33 is cleared. The process proceeds to the next step without processing, and the same processing as described above is performed (812).
~514).

Note that the present invention is not limited to the operations shown in the above flowchart, but may be modified as appropriate.

Alternatively, a plurality of input terminals 41 may be provided, and a signal processing method may be selected according to each input.

(Effects of the Invention) As described above, according to the present invention, a signal indicating whether the power supply, etc. of the input/output module is normal or not is inputted, and the input signal and output signal are appropriately processed according to the input of the signal. This allows the equipment to be controlled safely.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing the hardware configuration of a remote input/output controller showing an embodiment of the present invention, Fig. 2 is a flowchart showing its operation, and Fig. 3 shows the main unit of the programmable controller and the remote input/output controller. FIG. 4 is a block diagram showing the relationship between the two, and FIG. 4 is a time chart showing the characteristics when the power supply voltage of the input/output module is cut off. Agent Patent Attorney Muneharu Sasaki Figure 1 2.2

Claims (1)

[Claims] An input means for inputting a signal detected as to whether the input is in a normal state, and controlling output information from the base unit and input information to the base unit based on the input from the means and a predetermined setting command. A remote input/output controller comprising a control means.