GW Instek GDS-2000A series Quick start guide for Logic analyzer option - Manual (Page 10)

Using the Bus Key
The Bus key configures the UART, SPI, I 2 C or Parallel
buses.
1. Press the
B
BUS
key to access the Bus menu and
to display the bus on the display.
 Only those digital channels that have been
activated from the Logic Analyzer menu will
be accessible from the Bus menu.
 Pressing the Bus key again will remove the
bus from the display.
UART Bus
The UART bus menu is designed to decode RS-232 and
other common RS-232 variants such as RS-422 and RS-
485.
1. Press the Bus soft-key and select UART.
2. Press Define Inputs to select the Tx and Rx inputs
as well as the signal polarity.
3. Press Thresholds to set the thresholds.
 There are 5 pre-set threshold levels in
addition to the User-defined threshold
setting (TTL, 5.0V CMOS, 3.3V CMOS,
2.5V CMOS, ECL, PECL, 0V).
4. Press the Configure to set the baud rate, data bits,
parity and packet settings.
5. Press Bus Display to configure how the data is
displayed, either hex or binary.