Serega

Okay, I'll try to follow your advice in a few days when I'm around the controllers. Converter model https://expertdaq.com/en/product/ex9520/

Yes, this is my mistake. It appeared because I tried to restore settings from archived projects in the office. In this case, I missed the speed. In fact, the speed is 19200, not 9600. If I had different speeds, then slave 2 would not give an answer to the master.

Yes, I tried to load an empty project and I did Initial & Reset . But I don't remember if I did Initial & Reset on an empty project or on a working one. It is important?

Settings

Yes, I know that the 350th (V350-35-B1) can be configured as 485. But this was done a long time ago. I'll try to do it directly if I can't find a solution to the problem. 350 has two serial ports. One port is a modbus master, the second port is a modbus slave - it transmits data to SCADA. If necessary, I connect to the second port using VisiLogic . There is no ethernet port in 350, only EXP Port. Yes. I will try to post the port settings here.

1. Yes, there may be a problem with the resistors. I need to hook up an oscilloscope to find out. But it is unlikely that the problem is in them - there is data exchange over the bus. 2. I checked the port settings. I even tried changing the parity. It didn't work. 3. Everything is fine with register numbers. I checked. The Modbus Slave device responds to the request and sends data to the master. The master does not receive data. 4. On modbus slave 2, I tried to change the timeout from 0 to 100 (x10 msc). No result.

I can't tell you the reason for using RS 232-RS 485 here. It was done a long time ago. I can assume that to isolate the field bus from the PLC bus. No, I have not tried to disable other devices on the bus. I'm going to make a note to try this.

Good afternoon. We have V 350 (Modbus Master) and V 700 (Modbus Slave 2). Modbus works on the RS 485 line and there are other Modbus devices (Slave) on the line. Master works well with Modbus Slave 1 device. But does not want to work with Modbus Slave 2 (V 700). At the same time, when monitoring data on the RS 485 line, there are no problems - slave 2 will respond to the master. I checked the settings of the ports V 700 and V 350. I tried to connect a laptop with Modbus slave simulator instead of V 700 - everything works. Tried to get modbus data from V 700 using laptop - everything works fine. For some reason, the V 350 and V 700 do not want to work with each other. Has anyone experienced something similar?

Good afternoon. We have a problem with the V700 touchscreen. The touchscreen worked fine. Then we downloaded a new program and problems with the touchscreen started. We tried to calibrate through the "Info mode" - without result. The calibration process is not completed, the square appears in the upper left then in the lower right corners. And so endlessly. We checked the readings of system variables - the values were "-1" . We tried to calibrate through SB 73 and SB 74 - everything is the same and without result. The film was removed, the fastening of the panel in the cabinet was released. The panel is new. What else can you try?