The two types of standard serial communication protocols are RS-232 and RS-485. Both are used to enable serial communication between devices, although they differed in number of ways. The difference between RS-232 and RS-485 can be seen in the type of data cable they use.
Definition of RS 232?
In the year 1962, the RS-232 serial cabling interface was created. It is the earliest cabling method for establishing a link between data terminal and data transmission equipment. For instance, a computer system can be connected to a printer.
Definition of RS 485?
The RS-485 is a serial interface, which was first introduced in 1998, is a technological development of the RS 232 serial cabling interface. Unlike RS-232, this communication protocol can support 32 linked devices, whereas RS-232 could only handle one.
Difference between RS-232 and RS-485 | RS-232 VS RS-485:
- RS 232 has 1 transmitter and 1 receiver only. While RS-485 has 32 transmitters and 32 receivers present on a single bus.
- The signaling type of RS-232 is unbalanced, whereas the signalling type of RS-485 is balanced.
- The RS485 data transfer rate is over 20 Mbps, but the RS-232 data transmission rate is only 10 kbps. The communication speed of RS-232 was a significant constraint, so RS485 was created to address it.
- RS-232 and RS-485 are data connection types that allow data to be sent between nodes in a network. The data transit between nodes is divided into two types: single-ended and differential. RS-232 is a single-ended data transport protocol. Because the data transport afforded by RS-232 was inadequate over long distances, the differential type RS 485 was adopted.
- In comparison to RS-485, RS-232 is less noise-resistant since 485 runs in differential mode, which lessens the impacts of ground shifts and induced noise in the network. This also aids in the resolution of data collision difficulties.
- The cable length of an RS232 cable is roughly 50 feet, which is fairly little in comparison to the 4000-foot cable length of an RS485 line. When the length of a RS 232 cable exceeds 50 feet, resistance and voltage loss becomes a problem.
- 232 provides receiver input resistance ranging from 3k to 7k ohms. With a value of more than 12k ohms, it is comparatively higher in the case of 485.
- Because it only connects two devices, the network topology offered by RS-232 is a point-to-point type. While the network topology enabled by RS-485 is multipoint in nature, this cabling strategy can connect numerous devices.
- RS-485 is utilized for transmission distances that are significantly longer than RS-232. This is due to the fact that RS232 has a slower transmission speed, making it inefficient for long-distance communication.
- The RS-485 driver load is 60 ohms, which is lower than the RS232 driver load, which is between 3k and 5k ohms.