이름 : Leanna Agar
이메일 : leannaagar@free.fr
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예식일 : How To Lose Money With Rs485 Cable
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Using the Solis Data Logging Stick, which uses WiFi to communicate, we were able to set up the inverter to send data to the remote soliscloud service, but we could not find any way to get capture data apart from scraping the basic status page built into the WiFi adapter which only gave watts being produced and daily output. To get the solar PV power from the roof down to the basement shed, we purchased 20 meters of 6mm armoured cable; this was routed down the back of the house and into the shed through the stone wall. On the Raspberry Pi, we also installed a 1-Wire Pi Plus board, and this is used with a temperature sensor fitted in the shed to monitor the air temperature, which is also posted to the MQTT server and Home Assistant. RS485 uses two wires and sometimes a ground connection, so we used a twin-screen cable to go between the inverter to the EM112 Series Energy Meter and then onto the Raspberry Pi with a DB9 connector connected to the RS485 Pi board. We installed a new Micro SD card with the latest Raspberry Pi OS, and after updating the software, the serial port and i2c bus were enabled.

Bus Probes can be configured and tested using our web-based test app (you will need to connect the probes to your PC or Android smartphone via our Web485 board). Using a repeater, the main cable is divided into different segments, each of which can be up to 700 m in length and connect 32 devices (this number includes the repeaters). The main cable must be no longer than 700 m! The branches must be no longer than 1200 m! The RS485 system used for Modbus communication provides a main cable (Bus or backbone), to which all the devices have to be connected with branches (also known as stubs) that are as short as possible. The maximum number of repeaters that should be serially connected is 3. A higher number introduces excessive delays in the communication system. The normal way to implement this is with a two wire system with differential signal levels. This has thick stone walls and a concrete ceiling and has space to install 2 inverters and a battery system later if required. We found that there are 10K ohm resistors fitted on the A & B data lines with the A channel having a 10K pull-up resistor to 3.3 volts and the B channel having a 10K pull-down resistor to ground.

We then added the 10K pull-up and pull-down resistors to the RS485 Pi board and connected it directly to the Solis inverter. The existence of an RS485 port on the socket makes it even a little bit more difficult. Therefore the pin assignment is a little bit different from the default pin assignment on the RJ11 socket. This MJ20-PRG module clicks in the PLC and provides one RJ11 socket for serial communications with a PC. The main difference is, that pin 1 and 6 on the RJ11 socket of the MJ20-PRG module are used as power supply. The RJ11 connector can be used for both RS232 and RS485. If we want to connect a PC with an Unitronics PLC, for example for programming or debugging reasons, we need a connection cable which is on one side fitted with a female DB9 connector, and on the other side with an RJ11 jack. Figure 1 shows an example of a correct Bus connection. Bus Probes are a family of low-power environmental sensors with an RS485 interface. When the DSR and DTR signals are not used, the two pins can be used for simultaneous RS485 communication.

A symmetrical pin-layout allows two DTEs, data terminal equipment, to be connected directly without use of a modem or other DCE, data communication equipment. In this case it is possible to connect the main inlet and outlet terminal directly to the terminals of an instrument without creating a branch. These pins are normally used for the DTR, data terminal ready and DSR, data set ready signals. For RS232a crossover cable is used where pin 1 is connected with pin 6 at the other connector, pin 2 with pin 5, etc. This interconnects the transmit and receive signals of both PLCs, and also the handshaking signals DTR and DSR. For RS232 a crossover cable is used where pin 1 is connected with pin 6 at the other connector, pin 2 with pin 5, etc. This interconnects the transmit and receive signals of both PLCs, and also the handshaking signals DTR and DSR. The A signals of all devices should be connected with each other and the same goes for the B signals. When in full RS232 mode, the six available pins are assigned to the most used RS232 signals.

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