Product Description:

The BTA20.3-NA-LF-VB-BS machine control board is produced by Bosch Rexroth Indramat and belongs to the BTA20 Machine Control Boards series. It is intended for mounting behind operator panels where it coordinates local safety devices, override functions, and serial bus communication with the higher-level CNC or PLC controller. In an automation cell, this board serves as the human-machine interface node, relaying field inputs, feed overrides, and emergency stop statuses to the central drive system. Its circuitry integrates signal conditioning and protective components so the assembly can be installed directly inside a control cabinet without extra interface modules.

To exchange process data, the board links to the control network through the INTERBUS-S / BT-BUS fieldbus. Each scan transfers a telegram that is 3 words wide and contains status, command, and diagnostic information. Local I/O capacity is 8 In / 8 Out, allowing direct wiring of limit switches, contactors, or indicator lamps. A built-in converter maps service traffic from RS232 to RS422/485 so long cable runs do not degrade signal integrity. When mounted in the cabinet, the card carries an IP20 housing rating, while one auxiliary emergency-stop contact, a dedicated pushbutton, and an indicator lamp form a hardwired safety chain that opens the power circuit independently of fieldbus commands.

On the front panel, operators receive tactile feedback through eight illuminated white keys and two rotary override switches. The enclosure face meets IP65, so the keys remain protected against dust and low-pressure water jets. The feed rate channel can be raised up to 120 %, while spindle speed is prevented from falling below 45 %; both limits are resolved by the switches using a 4-bit Gray code that the controller decodes without ambiguity. These manual settings are transferred across the fieldbus only after the switches latch, preventing unintended changes during adjustment.