The maximum cable length depends on the data rate and the type of cable used. As a general rule, the maximum cable length for RS-485 is around 4000 feet (1219 meters) at a data rate of 100 kbps. However, this can be affected by factors such as cable quality, noise, and termination.
To prevent signal reflections, a termination resistor (typically 120 ohms) should be placed at each end of the RS-485 bus. The termination resistor should be connected between the differential signal lines (A and B) and should be matched to the characteristic impedance of the cable.
Yes, the SN75116D can be used in a multi-point configuration, where multiple transceivers are connected to the same bus. However, it's essential to ensure that only one device is transmitting at a time to prevent data collisions and bus contention.
The minimum input voltage required for the SN75116D to function properly is 4.5V. However, it's recommended to operate the device at a voltage between 4.75V and 5.25V for optimal performance.
To handle hot-swapping or inserting/removing devices from the RS-485 bus, it's recommended to use a bus buffer or repeater that can handle the transient conditions caused by device insertion or removal. Additionally, the device should be designed to handle the bus fault conditions and recover from them.
SN75116D datasheet
by Texas Instruments
Findchips
Findchips