How to connect plc to hmi
I want to modify the timer’s time with the touch screen.
1. Read out the program in FX2N PLC with software, find the constant value K of the timer used to set the time, modify the constant K to D directly when programming, D should choose power off to keep the data register, the range is between D200-D511, and other fixed, and then write it into PLC.
2. Choose the type of touch screen, it is recommended to choose the Vinylon MT6056iv touch screen, programming with software, a numeric setting button, the button corresponding to the PLC data register D, when the finger touches the button, there will be numeric input keyboard, at this time, you can modify the timer time.
In the market, any touch screen and PLC usually do not communicate well. There are four problems to be confirmed.
1, is the PLC parameter consistent with that in the project?
2, whether the communication line is connected to the pin according to the wiring diagram.
3, the project set up the COM port on the screen when the correct 4. Parameters and line confirmation OK, in the case of PLC program or PLC address problem.
Methods: (first judge parameters:)
1. Use the programming software of PLC to connect with the PLC test to see what the parameters of PLC are and whether the parameters set in the project are consistent with the test results.
2. On-line simulation: with our configuration software, using the plc’s own communication cable and computer connection, on-line simulation to see if the project is communicating. You can use a numeric input unit or switch to operate on it, to see if the simulator is turned off and then on-line simulation before the operation is still, whether direct prompt NC. (NC and previous operations have not been written down.
(test line): use the multimeter to define the test wiring according to the pin of the wiring diagram.
A: parameters of touch screen. Check the parameter settings of the touch screen.
There are several parameters that need special attention.
1: Communication Port Settings – – – – – – – – – – Make sure that the PLC connects to the touch screen COM1 port or COM2 port
2: Type of equipment – – – – – – – – – – – – – – – – – – – – – – This is the most important, if the agreement is not chosen correctly, the others do not have to say
3: Connection mode – ————– PLC and touch screen connection, confirm good news RS485, or RS232C
4: Interface parameters and PLC station number – ———– must be consistent with the PLC settings.
B: if the parameter confirmation is set up, then check the wiring problem. Confirm the correctness of RS485 and RS232C, and touch screen is different from all kinds of PLC wiring. This can refer to dimensional control (PLC and touch screen communication line help files).
This is the basic method of normal troubleshooting communication problems.
Next we will teach you how to bypass the problem of touch screen — online simulation.
When communication fails, some customers guess that it may be a touch screen problem or an interface problem.
Online simulation is to bypass the touch screen and connect directly to the computer with PLC.
1:PLC is connected to the computer through RS232. Some PLC have RS232 interface, some do not, and none can connect to the computer through the adapter.
2: build a simple project. Put two components, a numeric value, a numeric input. Address to set the address in PLC.
3: the setting of engineering parameters must be the same as that in PLC.
4: click on the online simulation function, so you can clearly check whether PLC can communicate with PC. If you can communicate, you can exclude the problems of PLC, and the problem of parameter setting.