User’s Manual UDP6900 Series Digital Control Power Supply
Instruments.uni-trend.com 36 / 44
RS232 Interface
RS485 interface (refer to the figure of 3.15 Terminal Function on Rear Panel). It can connect to RS485
interface of other master controller via a cable.
RS485 Interface
Before communication, please check whether the serial port settings and local address (only valid under
Multi-SCPI and Modbus protocol) are correct.
Baud rate: 9600, 14400, 19200, 38400, 57600, 115200
Parity check and data bits: no parity check, 8 bits of data bits, 1 bit of stop bit
Communication Settings
(1) Enter the menu settings.
(2) “System Settings” → “Communication Settings”, adjust the baud rate, communication protocol
and address.
(3) Multi-machine connection settings: Select communication protocol (SCPI, Multi-SCPI, Modbus)
in "System Settings".
SCPI only supports master-slave point-to-point communication, while Multi-SCPI and Modbus
support multi-slave communication (different addresses need to be set).
Note: Please refer to "SCPI Programming Manual" for SCPI and Multi-SCPI protocols, and "Modbus
Programming Manual" for Modbus protocol.
Multi- machine Communication Hardware Connection Diagram Based on RS485