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RS-232 Control Tutorial for Model BDS-HF300AFP

This page provides detailed instructions for using the RS-232 serial interface to remotely control and monitor the Model BDS-HF-AFP RF power generators.

For this part of the discussion, we are referencing the use of the serial control software (for your PC) called Teraterm. We have downloaded and are using version 4.87 You can download a copy by pasting this link into your browser or searching on “Teraterm”:


Teraterm  Setup

COM 1      38400    8 Bit    Parity=None    Stop=1 Bit    Flow Control=None    No Delays

The RS232 communication cable (PC>BDS-HF-AFP) pin out is as follows: 

PC Side  –    HF-AFP Side

Pin 2       –     pin 3

Pin 3       –     pin 2

Pin 5       –     pin 5

BDS-HF Operation

  • Please note the following control characteristics when designing your control program:
    • To maintain communication with the RS232 port on the BDS-HF it is necessary to send a command to the device every 2-3 seconds. For example you can sent the command “g” which is the “Query the Forward and Reflected Power”.
    • During an RF “ON” condition, there is a 4 second system watchdog timer that forces the RF Output to OFF if there is no sensed activity. This feature is in place to comply with typical safety standards such as in the event that the RS-232 control cable became disconnected. So, to keep the RF output turned ON, the specific command or a carriage return “CR” is required to be transmitted every 3.5 to 4 seconds.
    • All commands are to be typed in lower case.
    • All commands are to be ASCII characters.
    • All answers are will be transmitted to the host computer in upper case (capital) letters.
    • All unrecognized commands will be replied to with an upper case letter, for example: “N” (not acknowledged).
    • Use the command character “?” + CR to list the complete BDS-HF command set.
    • Enter command(s) as: letter + space + numeral +CR