“Many RS-485 users are completely unaware that they are taking unnecessary risk with their data because of the method they use for driver control,” warns Jeff Hunter, Design Engineer at Sealevel Systems. To assist users in selecting the ideal method, Sealevel Systems has published a white paper: Eliminate the Risk of RS-485 Data Corruption.
The EIA RS-485 specification does not stipulate the method for controlling the driver, therefore a number of options have evolved. Some methods have a significant risk of data contention and corruption because of the time required for a device to relinquish control of the RS-485 network once communication is complete.
The Sealevel white paper evaluates the most common RS-485 driver control methods: application program control (under windows), one-shot (uses a circuit to activate the enable/deactivate signal), enable driven when data present (hardware approach connecting transmitter data line to transmitter enable pin), automatic driver control (software automatically recognizes commands to transmit/disable), and automatic hardware enable (latest innovation using hardware circuitry on the board to control the RS-485 communications).
“I strongly encourage RS-485 users to read the white paper and learn about the new driver control methods that eliminate the risks of data contention and corruption” advised Hunter. “Eliminate the Risk of RS-485 Data Corruption” white paper is available from the Sealevel.com website or you can request a copy by calling Sealevel at 864.843.4343.