The RS-485 module for Arduino and Raspberry allows users to perform industrial and domotic applications. The RS-485 is the most versatile communication standard in the standard
This a standard defining the electrical characteristics of drivers and receivers for use in digital systems. It does not specify or recommend any communications protocol. In the next table the electrical characteristics of the standart are defined.
The RS-232 standard was first introduced in 1962 by the Radio Sector of the EIA. The original DTEs (data terminal equipment) were electromechanical teletypewriters, and the original DCEs (data circuit-terminating equipment) were usually modems.
For many years, an RS-232-compatible port was a standard feature for serial communications, such as modem connections, on many computers. The RS-232 standard is still used to connect industrial equipment (such as PLCs), console ports and special purpose equipment.
CAN is a multi-master broadcast serial bus standard for connecting electronic control units (ECUs). Each node is able to send and receive messages, but not simultaneously. A message consists primarily of an ID (identifier), which represents the priority of the message. A CAN message that is transmitted with highest priority will succeed and the node transmitting the lower priority message will sense this and back off and wait.
The information is transmitted by two twisted wires that connect all system modules. It is transmitted by voltage difference between the two levels. The high voltage value represents 1 and low 0. Its combination forms an appropriate message.
The 4-20 mA Current Loop Board is one of the most robust sensor signaling standard. Current loops are ideal for data transmission because of their inherent insensitivity to electrical noise. In a 4-20 mA current loop, all the signaling current flows through all components; the same current flows even if the wire terminations are less than perfect.
All the components in the loop drop voltage due to the signaling current flowing through them. The signaling current is not affected by these voltage drops as long as the power supply voltage is greater than the sum of the voltage drops around the loop at the maximum signaling current of 20 mA.
Modbus allows communication between many devices connected to the same network, for example a system that measures temperature and humidity and communicates the results to a computer
Many of the data types are named from its use in driving relays: a single-bit physical output is called a coil, and a single-bit physical input is called a discrete input or a contact.