It gets away most of the time with this configuration, with the shield draining noise and providing the ground reference at the same time. Why? Even without the shield, the RS485 network is quite robust. This works and is sometimes also recommended by many vendors. When the devices on the RS485 network are all opto-isolated, it is common practice to use a 2 wire twisted pair shielded cable, where the shield is used also as "return path" (ground) and is connected to each device like shown here: The circuit reference may be established by a third conductor connecting the common leads of devices, or it may be established by connections in each using equipment to an earth reference."
#Rs485 optical isolator generator
"Proper operation of the generator and receiver circuits requires the presence of a signal return path between the circuit grounds of the equipment at each end of the interconnection. But these are signal wires and the network always requires a return path. The 2 wires are sometimes referred as "+" and "-" instead of "A" and "B", making the user think that 2 wires is all you need to make it work.
#Rs485 optical isolator plus
The RS485 network is wrongly referred to as a "2 wires plus shield" network. The shield works as a "drain" for any noise that could be picked up by the RS485 network and "drain" it to ground. No matter the devices, it is always good on real site installation to use a shielded cable, with 18-22AWG wiring and the shield connected ONLY to one end of the line.
#Rs485 optical isolator how to
It is important to know how to wire devices on an RS485 network, especially when a non opto-isolated device is present. Some RS485 devices come with optical isolators installed (also called Galvanic isolation) on the RS485 port, and some don't. Transparent communication protocol, 1.2k to 187.5kbps baud rate automatic self-adaption.How do I wire RS485 devices? A quick schematic guide on how to wire RS485 devices All the signal communication ports have anti-surge protection function. Demountable module design, easy to install. 1.5kV isolation among input, output, power supply. 22.5mm thickness slim package, 35mm din rail-mounted. 1 channel RS232 or RS485 to 4-channel RS485 conversion. 2-Wire BUS System electric signal isolation and cable extension
It can be used in harsh environment and provides an effective solutions for user. It provides great convenience for technicians to do maintenance and installation.That RS485 hub is dismountable, its wiring terminal blocks can be dismounted, slim size, standard 35mm din rail-mounted case. It can automatically isolate fault bus andprovide error indication to ensure the normal operation of other channels. That RS485 hub has 1.5KV electric isolation, intelligent isolation design, automatically real-time check data operation and monitor bus status. HICM206 Intelligent RS485 hub is a kind of cost-effective industrial grade device, it is widely used in industrial automatic control equipment, security system, intelligent meters and instruments, etc.
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