RIGOL MSO/DS1000Z Series - Manual (Page 106)

RIGOL Chapter 5 To Trigger the Oscilloscope
5-32 MSO1000Z/DS1000Z User’s Guide
RS232 Trigger (Option)
RS232 bus is a serial communication mode used in the data transmission between
PCs or between PC and terminal. In RS232 serial protocol, a character is transmitted
as a frame of data which consists of 1 bit start bit, 5~8 bits data bits, 1 bit check bit
and 1~2 bits stop bit(s). Its format is as shown in the figure below.
MSO1000Z/DS1000Z oscilloscope triggers when the start frame, error frame, check
error or the specified data of the RS232 signal is detected.
Figure 5-13 Schematic Diagram of RS232 Protocol
Trigger Type:
Press Type to open the trigger type list. Rotate to select "RS232" and press
down . At this point, the trigger setting information is displayed at the upper right
corner of the screen.
For example, . The trigger type is RS232 trigger; the current
trigger source is CH1; the trigger level is 0.00 V.
Source Selection:
Press Source to open the signal source list and select CH1-CH4 or D0-D15. For the
details, please refer to the introduction in " Trigger Source". The current trigger
source is displayed at the upper right corner of the screen.
Note: Select channel with signal input as trigger source to obtain stable trigger.
Polarity
Press Polarity to select the polarity of data transmission. It can be set to " "
or " " and the default is .
Trigger Condition:
Press When to select the desired trigger condition.
 Start: trigger on the start frame position.
 Error: trigger when error frame is detected. After this trigger condition is
selected:
--press Stop Bit to select "1 bit" or "2 bits";
--press EvenOdd to select "None", "Odd" or "Even".
The oscilloscope will determine error frame according to the preset parameters.
 ChkError: trigger when check error is detected. When this trigger condition is
selected, press EvenOdd to select "Odd" or "Even". The oscilloscope will
determine check error according to the preset parameters.
 Data: trigger on the last bit of the preset data bits. When this trigger condition is