Since RS-485 is a Multi-point Specification > 자유게시판

Anyone who has seen a device go up in smoke, is likely to be very vehement on how to, and how not to wire grounds. Grounds between buildings may vary by a small voltage, but with very low impedance and hence the possibility of catastrophic currents - enough to melt signal cables, PCB traces, and transceiver devices. When the input of an RS-485 driver goes high, one of the outputs will go high in reference to circuit common and the other will go low. This means that low data rates can handle an improperly terminated (or even unterminated) cable better than high data rates. The VR-18 Paperless Chart Recorder can be connected to a PC with an Ethernet cable allowing students to use the Brainchild's FREE software, allowing for streaming live data or downloading the data to an Excel spreadsheet to further manipulate the information for reports and assignments. Development tools with support, information materials and instructions. See the sections on termination and biasing for more information. This frame ground is shown as being connected to the "green wire ground of power system", more commonly called earth ground. The first is to connect the signal common of the driver/receiver circuit to "protective or frame ground" through a 100 Ω resistor.

The RS-485 circuit common is connected to earth ground in both PCs. If the circuit common is truly isolated from earth ground, then scuffing your feet on carpet (to pick up an ESD charge) and touching the wires can cause the wires to shift potential several thousand volts. The problem with this is that a particular method of grounding may be required for one installation to function and cause damage at another. The third installation uses the same two computers as the second example, but they are separated by several thousand feet of wire, and one of the computers is sitting next to an arc furnace that draws several thousand amps when operating. This solar solution has proven to be especially beneficial to companies that install solar PVs and are looking to quantify the energy in order to provide a record of ROI for businesses. We offer intelligent digital meters for energy saving and eco-friendly. These devices allow you to view and modify the parameters of heat controllers, connected to the RS485 port via the communication protocol and the NCP to monitor the parameters of heat meters (Mbus), connected to RS232 port via a converter RS232/Mbus (M-bus master).

12V and -7V. If the desktop's port is ESD protected damage may not occur, but there is no guarantee. The current could cause damage to the wire, RS485 standard or the RS-485 port. The desktop is connected to earth ground and the RS-485 port is referenced to the earth ground. The first is a desktop computer talking to a laptop. Since the laptop has no connection to earth ground, there will normally be little current through this third wire. 4 (DI - the driver's input pin) is high, the output voltage on pin 6 (The A output) will be positive with respect to pin 7 (the B output). The TX output of a first device connected to the RX input of a second device, and the TX output of the second device connected to the RX input of the first device. Functionality of the protocol converter (computing) - Data from the input interface, Ethernet is the conversion and output transmission or GPRS interfaces to external modules. RS-232 does not define a protocol, but the protocol that is almost always transmitted on these connectors is asynchronous start-stop ASCII (data from a UART).

Typical use (3 functions: CLV) - the function of protocol converter (Convert) - retrieve data from the input interface, Ethernet, then the conversion and transfer them to the output interfaces to external or GPRS module. Under some conditions it can be used up to data transmission speeds of 64 Mbit/s. Adapted for constant operation under industrial conditions. Installations based on the iMod currently operate in many countries of the world, and thanks to the constant development of the platform and remote updates, it is always possible to gain access to new functionalities. Consider three different installations. Communications. Servicing of the economic 1-Wire bus visualization typically used for reading of temperature sensors. The iMod SDK based on the JAVA language makes it possible to add servicing of your own industrial automation protocols. They will usually add some hysteresis to the receiver to reduce its sensitivity to noise, but biasing will decrease the receivers noise sensitivity.