How to avoid communication failures when the message is detailed 0 3

With CPU S7 315F, ET 200S and fail-safe DI DO module, you will invoke the fail-safe program of the OB35. Moreover, you have accepted the default values for all monitoring times and are willing to receive a "communication failure" message. OB 35 is set to 100 ms by default.

You have set the F monitoring time for the FIO module to 100 milliseconds, so you want to address the IO module at least once every 100 milliseconds. However, since OB 35 is only called once every 100 milliseconds, a communication failure occurs. To ensure that there is a difference between the OB35 scan interval and the F monitoring time, make sure that the F monitoring time is greater than the OB35 scan interval.

This problem occurs in S7 distributed security systems all the way up to SP1 and 6ES7138-4FA00-0AB0,6 ES7138-4FB00-0AB0,6ES7138-4CF00-0AB0. In the new module, the f monitoring time is set to 150 milliseconds.

Such messages can only be avoided if reliable communication is established.

With CPU S7 315F, ET 200s and fail-safe DI DO module, then you would call OB35 9: What does the "clock" correction factor mean in the hardware configurator? In the hardware configuration,

In order to exchange data between two S7-300 workstations using CPU 317-2PN DP via an S7 connection, where the S7 connection is configured using NetPro, in S7 communication, the communication function block must be invoked. Module FB14 ("get") for fetching data from the remote CPU, module FB15("put") is used to write data to the remote CPU. The function blocks are included in the standard library for Step 7.

CPU 317-2PN DP communication module FB14 ("get") and FB15 ("put") property:

FB14 and FB15 are asynchronous communication functions. The operation of these modules may span multiple OB1 cycles. Activate FB14 or FB15 via the input parameter REQ.

Done, NDR, or Error indicates that the job is complete. PUT and GET can communicate over a connection at the same time.

Note: Communication blocks from the library SIMATIC Net CP cannot be used for CPU317-2PN DP.

If the PLC shows a communication error, generally check whether the communication parameters of the PLC are configured correctly, check the serial slogan, baud rate, etc. if it is a serial port communication, and check whether the IP address is configured if it is a network communication. If there is no problem with the communication parameters, it is necessary to insist on whether the physical communication cable is normal.

In fact, it is generally necessary to cut off the total power for about 3 minutes before sending the power to see if it is restored.

If it is all faulty, you first check whether the communication power supply is normal, and the second one is to see if there is a problem with the communication module. To give you a detailed one.

How to check for common hardware failures in your computer.

For the soft fault of the computer, it can be solved by analyzing the fault phenomenon, reinstalling the system, replacing the software, modifying the software program, or removing the computer virus. For hard faults, it is necessary to check and eliminate them step by step according to the inspection principle, and the following ten inspection and judgment methods for hard faults are introduced

1.Plugging and unplugging method.

The "plug-in method" is a method of "unplugging" or "plugging" a plug-in to look for faults. For example, if the machine has a "deadlock" phenomenon, this method is used to pull out the plug-in board piece by piece, and if the machine returns to normal, it means that the fault is on the board.

2.Substitution method.

The "replacement method" is to replace the suspected problematic device with the one that has been determined to be the best, and gradually narrow down the search.

3.Comparative Law.

The "comparison method" is to compare the correct characteristics (waveform or voltage) with the characteristics (waveform or voltage) of the faulty machine to see which component's waveform or voltage does not match, and measure it pole-by-pole according to the logic circuit diagram, so that the signal is detected point by point in the direction of the source pursued, and the fault location is determined after analysis.

4.Measurement method.

The "measurement method", also known as the "static measurement method", is an effective method to try to suspend the computer in a specific state, measure the level of each point required with a multimeter according to the logic diagram, and analyze and judge the fault.

5.Heating method.

The "heating method" is a method to artificially raise the ambient temperature and accelerate the "death" of some components with poor high temperature parameters to find faults.

6.Percussion.

The operation of the machine is good or bad, which may be caused by the false soldering or poor contact of the pins of the components and components, or the increase of the resistance of the metal through hole. In this case, it is much easier to use the percussion method to check the circuit board by gently tapping the board with a rubber hammer and then checking it again.

7.Partition method.

The segmentation method is a method of "splitting" the fault, gradually shrinking the board, narrowing it to a certain line, and then to a certain point.

8.Direct observation.

The true observation method is to use human senses to directly observe sparks, abnormal sounds, overheating, scorching and other phenomena to determine the power supply short circuit, overcurrent, overvoltage, loose plug-ins, corrosion damage and other obvious faults.

9.Isolated compression method.

That is, according to the phenomenon of the fault and the hardware parts, some information about the relevant parts is temporarily disconnected or the original data is simplified to reduce the search range.

10.Procedural testing method.

That is, the use of boot self-test program, advanced special diagnostic program to help find the cause of the fault, the diagnostic program in the form of a menu to provide a number of hard drive, floppy drive, CD-ROM, printer and other detection, if the hardware failure, the display of error, sound to obtain the fault point and its cause.

If there is data loss on the touch screen, you can reset it, if there are two machines of the same model, you can compare the settings, if the program is lost, you can only change the program card.

If it is user data, it can be rewritten, and if it is the underlying program, it can only be replaced.