Chapter 8 Protocol Decoding. Rigol DS2000A Series, MSO2000A Series

RIGOL Chapter 7 Digital Channel

To Use the Digital Bus

Users can display the three groups of channels (D7-D0, D15-D8 and D15-D0) as digital buses according to their needs. Each bus value will be displayed at the bottom of the screen in data or graph form. You can create up to 2 buses.

Press LA  Bus to enter the digital bus setting menu.

 Press Bus to select “BUS1” or “BUS2”.

 Press BusStatus to turn on or off the digital bus.

 Press Sel CH to set the corresponding channels of BUS1 or BUS2 to D7-D0,

D15-D8 or D15-D0.

 Press Endian to set the bus endian to “Normal (D0 locates at the least significant bit)” or “Invert (D0 locates at the most significant bit)” and the default is “Normal”.

 Press RefClock to select any channel of D0-D15 or CH1-CH2 as the reference clock of the bus. Selecting “None” means no reference clock will be used.

When CH1 or CH2 is selected to be the reference clock, you can press

Threshold and rotate the multifunction knob to set the threshold of the clock channel, the range is from (-4*vertical scale - vertical position) to

(4*vertical scale - vertical position). Pressing down can quickly reset the threshold level of the clock channel to 0 V. When any channel of D0-D15 is selected to be the reference clock, Threshold will be hidden automatically and the threshold cannot be set.

 Press Slope to set the sample edge type of the reference clock to (rising edge) or (falling edge).

 Press Type to set the display mode of the digital bus to “Data” or “Graph”. In data mode, the bus data is displayed; in graph mode, the oscilloscope displays the level of the corresponding value of the bus data for easier observation of the variation tendency of the bus values.

 Press Format to set the display format of the digital bus to Hex, Decimal, Binary or ASCII.

 Press Jitter Reject to turn on the jitter rejection function. Jitter refers to the short-term deviation of the signal relative to its ideal time position at certain time point, as shown as T1 and T2 in Figure 7-1. When no reference clock is selected for the bus, the jump status of each channel would cause the variation of the bus data and undesired data would be generated due to jitter when the

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Chapter 7 Digital Channel RIGOL bus data varies. When the jitter rejection is turned on, the bus does not display the variation of the bus data caused by certain jitter time and still holds the effective data.

 Press Jitter Time and use or the inner knob of the navigation knob to adjust the jitter time at a relatively smaller step or use the outer knob of the navigation knob to adjust the jitter time at a relatively larger step. The range is from 1 ns to 1 ms.

Note: Jitter rejection and jitter time can be set only when no reference clock is selected.

Signal

Ideal Clock

Figure 7-1 Digital Bus Jitter

To Set the Label

Press LA  Label to set a user-defined label for specified digital channel.

 Use preset labels

Press Sel CH to select the digital channel (any channel of D0-D15) that needs to set a label.

Press Preset and rotate to select a desired label. The available labels include ACK, AD0, ADDR, BIT, CAS, CLK, DATA, HALT, INT, UB, LOAD, NMI, OUT,

PIN, RAS, RDY, RST, RX, TX and WR.

 Input a label manually

Press Sel CH to select the digital channel (any channel of D0-D15) that needs to set a label.

Press Input to enter the label input interface to input a label manually. For the input method, refer to the introduction in “ Channel Label”.

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RIGOL Chapter 7 Digital Channel

Digital Channel Delay Calibration

When using the oscilloscope for actual measurement, the transmission delay of the probe cable may cause relatively larger error (zero offset). Zero offset is defined as the offset of the crossing point of the waveform and threshold level line relative to the trigger position. For MSO2000A, users can set a delay time to calibrate the zero offset of the digital channels.

Press LA  Delay-Cal and rotate to set the delay calibration time. The range is from -100 ns to 100 ns.

Note: This parameter is related to the instrument model and the current horizontal time base. The larger the horizontal time base is, the larger the setting step will be.

Take MSO2302A as an example, when the horizontal time base is 50 ns, the step is 1 ns; when the horizontal time base is 2 μs, the step is 40 ns; when the horizontal time base is greater than or equal to 10 μs, the delay calibration time cannot be adjusted.

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Chapter 8 Protocol Decoding RIGOL

Chapter 8 Protocol Decoding

Protocol analysis can be used by users to discover errors, debug hardware and accelerate development easily, so as to guarantee quick and high-quality accomplishment of projects. Protocol decoding is the basis of protocol analysis. Only protocol analyses with correct protocol decoding are acceptable and only correct protocol decoding can provide more error information. MSO2000A/DS2000A provides two buses to make common protocol decoding (including Parallel (standard),

RS232 (option), I2C (option), SPI (option) and CAN (option)) of the analog channels

(CH1 or CH2) and digital channels (D0-D15). As the decoding functions and setting methods of the two buses are the same, this chapter only takes Decode1 for illustration.

To get the decoding option information, please refer to the introduction in

“Appendix A: Accessories and Options”.

When you have ordered the decoding option, please refer to the introduction in

“Option Management” to activate corresponding option.

The contents of this chapter:

 Parallel Decoding

 RS232 Decoding (Option)

 I2C Decoding (Option)

 SPI Decoding (Option)

 CAN Decoding (Option)



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RIGOL Chapter 8 Protocol Decoding

Parallel Decoding

Parallel bus consists of clock line and data line. As shown in the figure below, CLK is the clock line, while Bit0 and Bit1 are the 0 bit and 1st bit on the data line respectively.

The oscilloscope will sample the channel data on the rising edge, falling edge or the rising/falling edge of the clock and judge each data point (logic “1” or logic “0”) according to the preset threshold level.

Figure 8-1 Parallel Decoding

Press Decode1  Decode to select “Parallel” and open the parallel decoding function menu.

1.

Clock Line Setting (CLK)

Press CLKChannel to select any channel (CH1, CH2 or any channel of D0-D15) as the clock channel. If “None” is selected, no clock channel is set.

Press Slope to set the oscilloscope to sample the channel data on the rising edge ( ), falling edge ( ) or rising/falling edges ( ). If no clock channel is selected, the instrument will sample when the channel data jumps during the decoding.

2.

Data Line Setting

 Set the bus bits

Press Bus Bits to set the data width of the parallel bus namely the number of bits per frame. The default is 8 and the maximum is 18 bits (Bit0,

Bit1…Bit17).

 Specify data channel for each bit.

First, press CurrentBit to select the bit that needs to specify channel. The

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Chapter 8 Protocol Decoding RIGOL default is 0 and the range available is from 0 to (the bus bits-1). For example, when the bus bits is 18, the range available is 0, 1…17.

Next, press Channel to specify a channel source for the bit currently selected in CurrentBit. The channel source can be CH1, CH2 or any channel of D0-D15.

3.

Analog Channel Threshold Setting

Press Threshold to open the threshold setting menu.

 Press Channel to select the desired channel (CH1 or CH2).

 Press TTL, CMOS or ECL to set the threshold of the specified channel to the corresponding level value; or press Threshold and use to set the threshold. The settable range is from (-5*vertical scale - vertical position) to

(5*vertical scale - vertical position). The default is 0 V. Pressing down can quickly reset the threshold level to 0 V.

Note: When the threshold selected is beyond the specified range, it will be automatically limited within the range.

4.

Display-related Setting

Press Format to set the display format of the bus to Hex, Decimal, Binary or

ASCII.

Press Offset and use to adjust the vertical display position of the bus.

Press BusStatus to turn the bus display on or off.

5.

Event Table

The event table displays the decoded data and the corresponding line number and time in table format. It can be used to observe relatively longer decoded data. Press Event Table  Event Table to select “ON” (This operation is only available when BusStatus is set to “ON”) to enter the event table interface as shown in Figure 8-2.



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Figure 8-2 Parallel Event Table

At this point, “Table” is selected in the View menu automatically and the menu is grayed out. The decoded data is displayed in table format following the time order. If an USB storage device is currently connected to the instrument, press

Export to export the data table to the external USB storage device in CSV format.

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RS232 Decoding (Option)

RS232 serial bus consists of the transmitting data line (TX) and the receiving data line (RX).

The industry standard of RS232 uses “Negative Logic”, namely high level is logic “0” and low level is logic “1”.

0 0 0 0

1 1 1 1 1 1

Figure 8-3 RS232 Industrial Standard Schematic Diagram

By default, RS232 uses LSB (Least Significant Bit) transmission sequence, namely the lowest bit of the data is transmitted first. While for MSB (Most Significant Bit), the highest bit of the data is transmitted first. t t

Endian (LSB) Endian (MSB)

In RS232, you need to set the start bit, data bits, check bit (optional) and stop bit of each frame of data.

Start Bit: represent when the data starts outputting.

Data Bits: represent the number of data bits actually contained in each frame of data.

Check Bit: used to check the correctness of the data transmission.

 Odd Checkout: the total number of “1” in the data bit and check bit is an odd.

For example, when 0x55 (01010101) is sent, a 1 needs to be filled in the check bit to make the number of 1 be an odd.

 Even Checkout: the total number of “1” in the data bit and check bit is an even.

For example, when 0x55 (01010101) is sent, a 0 should be filled in the check bit.

 None: there would not be check bit during the transmission.

Stop Bit: represent when the data stops outputting.



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Press Decode1  Decode to select “RS232” to open the RS232 decoding function menu.

If the current trigger type of the trigger system is RS232, pressing CopyTrig can copy the current RS232 trigger settings (include the source channel, polarity, stop bit, even-odd check mode, data bits and baud rate) and apply them to the RS232 decoding function. Then, if needed, you can still set the RS232 decoding parameters according to the introductions below.

Note: The copy function is only available when the current trigger type is “RS232”; otherwise, CopyTrig is not available.

1.

TX and RX Channel Setting

Press TX to select any channel (CH1, CH2 or any channel of D0-D15) as the transmitting channel and when “None” is selected, no transmitting channel is set.

Use the same method the set the RX channel.

When an analog channel is selected for TX or RX, you need to set a threshold by pressing the TX or RX menu. The range is from (-5*vertical scale - vertical position) to (5*vertical scale - vertical position) and the default is 0 V.

2.

Polarity Setting

Press Polarity to select “Normal” (negative logic, namely the high level is logic

“0” and the low level is logic “1”) or “Invert” (positive logic, namely the high level is logic “1” and the low level is logic “0”) and the default is “Normal”.

3.

Endian Setting

Press Endian to select “LSB” or “MSB” and the default is “LSB”.

4.

Baud Rate Setting

Press Baud to select the desired baud rate and the default is 9600 bps. If “User” is selected, press Setup and use or the inner knob of the navigation knob to adjust the baud rate at a relatively smaller step or turn the outer knob of the navigation knob to adjust the baud rate at a relatively larger step. The range is from 110 bps to 20 Mbps.

5.

Data Packet Setting

As mentioned before, in RS232, you need to set the start bit, data bits, check bit

(optional) and stop bit of each frame of data. “Start Bit” is specified by the

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“Polarity Setting”. The setting methods of other parameters are as follows.

 Press Data Bits to set the data width of each frame. It can be set to 5, 6, 7,

8 or 9 and the default is 8.

 Press Stop Bit to set the stop bit after each frame of data. It can be set to

1 bit, 1.5 bit or 2 bit.

 Press Even-Odd to set the even-odd check mode of the data transmission.

It can be set to None, Odd or Even.

 Press Packet to enable or disable the packet end. When packet end is enabled, several data blocks are combined according to the packet end.

 Press PacketEnd to set the packet end during data transmission and it can be set to 00 (NULL), 0A (LF), 0D (CR), 20 (SP) or FF.

6.



ASCII.



7.

Event Table

The event table displays the decoded data, the corresponding line number, time and error information on TX and/or RX data lines in table format. It can be used to observe relatively longer decoded data.

Note: When the RX or TX channel is set to “None”, the information of this data line will not be displayed in the event table.

Press Event Table  Event Table to select “ON” (This operation is only available when BusStatus is set to “ON”) to enter the event table interface as shown in the figure below.



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Figure 8-4 RS232 Event Table

At this point, “Table” is selected in the View menu automatically and the menu is grayed out. The event data is displayed in table format following the time order. If error occurs during the decoding, the corresponding error information is displayed. If a USB storage device is currently connected to the instrument, press Export to export the data table to the external USB storage device in CSV format.

8.

The Error Expression during Decoding

MSO2000A/DS2000A makes full use of the resources such as color and view to express the results of the protocol decoding effectively so as to let users find the desired information quickly.

End Frame Error:

Errors generated when the end frame condition is not met. When the stop bit is set to 1.5, red error mark ( Note: The red mark is displayed in different modes according to the horizontal time base setting; when the horizontal time base is relatively smaller, is displayed; otherwise, is displayed) will be displayed if the stop bit is less than 1.5.

Check Error:

When check bit error is detected during the decoding, red error mark will be

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Chapter 8 Protocol Decoding RIGOL displayed. For example, when the transmitting terminal is set to none check and the decoder is set to odd check, the following check error occurs.

(00000100 ， LSB)

The check bit detected is 1

Wherein, there are odd number (1) of 1 in the 8-bit data 00000100 and the check bit should be 0; but the check bit detected on the TX is 1, thus check error occurs.

After the decoder is set to none check, the decoding becomes normal.

Note: Two error marks will be displayed when end frame error and check error are detected at the same time.



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I2C Decoding (Option)

I2C serial bus consists of the clock line (SCLK) and the data line (SDA).

SCLK: sample the SDA on the clock rising edge or falling edge.

SDA: denote the data channel.

SCLK

SDA

Figure 8-5 I2C Serial Bus

Press Decode1  Decode to select “I2C” and open the I2C decoding function menu.

If the current trigger type of the trigger system is I2C, pressing CopyTrig softkey can copy the current I2C trigger settings (include the clock signal and data signal) and apply them to the I2C decoding function. Then, if needed, you can still set the

I2C decoding parameters according to the introductions below.

Note: The copy function is only available when the current trigger type is “I2C”; otherwise, CopyTrig is not available.

1.

SCLK Setting

Press SCLK to select any channel (CH1, CH2 or any channel of D0-D15) as the clock channel.

If the clock channel is set to CH1 or CH2, press SCLKThreshold to set the threshold of the clock channel. The range of the threshold is decided by the vertical position and scale, and is from (-5*vertical scale - vertical position) to

(5*vertical scale - vertical position). If the clock channel is set to any channel of

D0-D15, SCLKThreshold will be hidden automatically.

2.

SDA Setting

Press SDA to select any channel (CH1, CH2 or any channel of D0-D15) as the data channel.

If the data channel is set to CH1 or CH2, press SDAThreshold to set the threshold of the data channel. The range of the threshold is decided by the

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Chapter 8 Protocol Decoding RIGOL vertical position and scale, and is from (-5*vertical scale - vertical position) to

(5*vertical scale - vertical position). If the data channel is set to any channel of

D0-D15, SDAThreshold will be hidden automatically.

3.



ASCII.

Press Offset and use to adjust the vertical display position of the bus.


4.

Event Table

The event table displays the decoded data, the corresponding line number, time, data direction, ID and ACK information in table or details format. Press Event

Table  Event Table to select “ON” (This operation is only available when

BusStatus is set to “ON”) to enter the event table interface.

At this point, you can press View to display the event table in “Table” form (as shown in Figure 8-6) or “Details” form (as shown in Figure 8-7). If a USB storage device is currently connected to the instrument, you can press Export to export the data table to the external USB storage device in CSV format.

Figure 8-6 I2C Event Table (Table)



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Figure 8-7 I2C Event Table (Details)

5.

Address Information during Decoding

In I2C bus, the front part of each frame of data contains the address information and blue patches are used to represent address ID. In the ID, “Write” is used to represent writing address and “Read” is used to represent reading address.

Press Include R/W. When “Open” is selected, “AddrBits” will include the

“R/W” bit as a part of the address value.

Address Information

Figure 8-8 Address Information during Decoding

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6.

Error Expressions during Decoding

When the ACK (ACKnowledge Character) is not met, the red error marks as shown in the figure below will be displayed. Note: The red mark is displayed in different modes according to the horizontal time base setting; when the horizontal time base is relatively smaller, displayed.

is displayed; otherwise, is

ACK=1

Figure 8-9 Error Expressions during Decoding



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SPI Decoding (Option)

SPI bus is based on the master-slave configuration and usually consists of chip select line (CS), clock line (SCLK) and data line (SDA).

SCLK: sample the SDA on the clock rising edge or falling edge.

SDA: denote the data channel.

SCLK

SDA

Figure 8-10 SPI Serial Bus

If the current trigger type of the trigger system is SPI, pressing CopyTrig can copy the current SPI trigger settings (include the CS/TimeOut mode, clock channel, data channel, data bits and so on) and apply them to the SPI decoding function as well as set the polarity of the SDA data line to high. Then, if needed, you can still set the SPI decoding parameters according to the introductions below.

Note: The copy function is only available when the current trigger type is “SPI”; otherwise, CopyTrig is not available.

Press Decode1  Decode to select “SPI” and open the SPI decoding function menu.

1.

Decoding Mode Setting

Press Mode to select “TimeOut” or “CS”.

When “TimeOut” is selected, press TimeOut and use or the inner knob of the navigation knob to adjust the timeout time at a relatively smaller step or turn the outer knob of the navigation knob to adjust the timeout time at a relatively larger step. The adjustable range is from 100 ns to 1 s. The default is 1 μs.

When “CS” is selected, press SS to enter the SS setting submenu. In this menu:

 Press Channel to select any channel (CH1, CH2 or any channel of D0-D15) as the CS channel.

 Press Polarity to set the polarity of the chip select channel to

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(positive polarity) or (negative polarity).

 If the CS channel is set to CH1 or CH2, you can press Threshold to set the threshold of the clock channel. The range of the threshold is related to the vertical scale and vertical position and is from (-5*vertical scale - vertical position) to (5*vertical scale - vertical position). If the CS channel is set to any of D0-D15, Threshold will be hidden automatically.

2.

SCLK Setting

Press SCLK to enter the clock line setting interface.

 Press Channel to select any channel (CH1, CH2 or any channel of D0-D15) as the clock channel.

 Press Slope to set to sample the SDA on the rising or falling edge of the

SCLK.

 If the clock channel is set to CH1 or CH2, press Threshold to set the threshold of the clock channel. The range of the threshold is decided by the vertical position and scale, and is from (-5*vertical scale - vertical position) to (5*vertical scale - vertical position). If the clock channel is set to any channel of D0-D15, Threshold will be hidden automatically.

3.

SDA Setting

Press SDA to enter the SDA data line setting interface.

 Press Channel to select any channel (CH1, CH2 or any channel of D0-D15) as the SDA data channel.

 Press Polarity to set the polarity of the SDA data line to (high) or

(low).

 If the data channel is set to CH1 or CH2, press Threshold to set the threshold of the data channel. The range of the threshold is decided by the vertical position and scale, and is from (-5*vertical scale - vertical position) to (5*vertical scale - vertical position). If the data channel is set to any channel of D0-D15, Threshold will be hidden automatically.

4.

Data Bits Setting

Press Data Bits to set the number of bits of each frame of data. The range available is from 4 to 32. The default is 8.

5.

Endian Setting

Press Endian to select “LSB” or “MSB” and the default is “MSB”.



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6.



ASCII.



7.

Event Table

The event table displays the decoded data, the corresponding line number, time and error information on the data line in table format. It can be used to observe relatively longer decoded data. Press Event Table  Event Table to select

“ON” (This operation is only available when BusStatus is set to “ON”) to enter the event table interface as shown in the figure below.

Figure 8-11 SPI Event Table

At this point, “Table” is selected in the View menu automatically and the menu is grayed out. The decoded data is displayed in table format following the time order. If a USB storage device is currently connected to the instrument, press

Export to export the data table to the external USB storage device in CSV format.

8.

Error Expressions during Decoding

When the clock for a frame in SPI is not enough, the data is filled with red patches. For example, when Data Bits is set to 7 and SCLK slope is set to rising edge, decoding error will be generated.

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CAN Decoding (Option)

You need to specify the CAN signal type and sample position for CAN decoding. The oscilloscope samples the CAN signal on the specified sample position.

Press Decode1  Decode and select “CAN” to open the CAN decoding function menu.

If the current trigger type of the trigger system is CAN, pressing CopyTrig softkey can copy the current CAN trigger settings (include the source channel, signal type, baud rate, sample position and so on) and apply them to the CAN decoding function.

Then, if needed, you can still set the CAN decoding parameters according to the introductions below.

Note: The copy function is only available when the current trigger type is “CAN”; otherwise, CopyTrig is not available.

1.

Source

Press Source and select any channel (CH1, CH2 or any channel of D0-D15) as the source channel.

If the source channel is set to CH1 or CH2, you can set the threshold of the corresponding analog channel. Press Threshold to open the threshold setting menu. Then, press TTL, CMOS or ECL to set the threshold of the specified channel to the corresponding level value; or press Threshold and use to set the threshold. The settable range is from (-5*vertical scale - vertical position) to

(5*vertical scale - vertical position). The default is 0 V. Pressing down can quickly reset the threshold level to 0 V.

Note: When the threshold selected is beyond the specified range, it will be automatically limited within the range.

If the data channel is set to any channel of D0-D15, Threshold will be hidden automatically.

2.

Signal Type

Press Signal Type to select the desired signal type.

 Rx: the received signal from the CAN signal line.

 Tx: the sending signal from the CAN signal line.



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 CAN_H: the actual CAN_H bus signal.

 CAN_L: the actual CAN_L bus signal.

 Differential: the CAN differential bus signals connected to an analog channel using a differential probe. The positive lead of the probe connects the CAN_H bus signal and the negative lead connects the CAN_L bus signal.

3.

Baud

Press Baud to select a baud rate (100 kb/s, 125 kb/s, 250 kb/s, 400 kb/s, 500 kb/s (default), 800 kb/s, 1 Mb/s or User) that matches the CAN bus signal. When

“User” is selected, press Setup and use or the inner knob of the navigation knob to adjust the baud rate at a relatively smaller step or turn the outer knob of the navigation knob to adjust the baud rate at a relatively larger step. The range is from 10 kb/s to 1 Mb/s.

4.

Sample Point

The Sample point is a point within a bit’s time. The oscilloscope samples the bit level at this point. The sample position is represented by the percentage of “the time from the start of the bit’s time to the sample point time” in the “bit’s time”.

Press Sample Point and use to adjust this parameter with a step of 1%.

The range is from 5% to 95% and the default is 50%.

1bit

60%

70%

80%

Figure 8-12 Sample Position Schematic Diagram

5.


Press Format to set the bus display format to Hex, Decimal, Binary or ASCII.


Press BusStatus to enable or disable bus display.

6.

Event Table

The event table displays the decoded data, the corresponding line number, time, frame ID, DLC, CRC and ACK information in table or details format. Press Event

Table  Event Table to select “ON” (This operation is only available when

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BusStatus is set to “ON”) to enter the event table interface.

At this point, you can press View to display the event table in “Table” form (as shown in Figure 8-13) or “Details” form (as shown in Figure 8-14). If a USB storage device is currently connected to the instrument, press Export to export the data table to the external USB storage device in CSV format.

Figure 8-13 CAN Event Table (Table)

Figure 8-14 CAN Event Table (Details)



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7.

Decoded CAN Data Interpretation

 Frame ID: displayed as hexadecimal number and expressed by blue patch.

 DLC (Data Length Code): displayed as hexadecimal number and expressed by chartreuse patch.

 Data: its display format depends on the format specified in Format (hex, decimal, binary or ASCII). It is expressed by green patch. If the data frame is lost, it will be expressed by red patch.

 CRC (Cyclic Redundancy Check): displayed as hexadecimal number. It is expressed by turquoise patch when valid and by red patch when error occurs.

 ACK (Acknowledgement): it is expressed by green patch when valid and by red patch when error occurs (the detected ACK is 1).

Frame ID DLC Data CRC ACK

Figure 8-15 Decoded CAN Data Interpretation

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Chapter 9 Reference Waveform

Chapter 9 Reference Waveform


 To Enable REF Function

 To Set the Color

 To Select REF Source

 To Save REF Waveform

 To Adjust REF Waveform Display

 To Export to Internal or External Memory

 To Import from Internal or External Memory

RIGOL



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RIGOL Chapter 9 Reference Waveform

To Enable REF Function

Press REF in the vertical control area (VERTICAL) at the front panel to enable the

REF function.

Note: When the time base is in X-Y mode, REF function cannot be enabled.

MSO2000A/DS2000A provides 10 reference waveform channels. Press Channel, rotate to select the desired reference channel and press down or Channel to turn the selected channel on or off. A channel icon (for example, ) of the channel enabled will be displayed at the left side of the screen grid.

When the REF function is enabled, you can select different color for each reference waveform, set the source of each reference channel, adjust the vertical scale and position of the reference waveform and save the reference waveform to internal or external memory as well as recall it when needed. For the details, please refer to the introductions below.

To Set the Color

MSO2000A/DS2000A series oscilloscope provides five colors (gray, green, light blue, magenta and orange) to mark the reference waveforms of different channels in order to distinguish them.

Press Current and use to select any of the reference channels (Ref1-Ref10) enabled. Then, press Color to specify a different color for the reference waveform of that channel. The corresponding icon at the left of the channel currently selected will be filled with the specified color, for example, .

To Select REF Source

Press Current and use to select any of the reference channels (Ref1 to Ref10) enabled and then press Source to specify a reference source (CH1, CH2, MATH or any channel of D0-D15) for this channel. Only the channels currently enabled can be selected.

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Chapter 9 Reference Waveform RIGOL

To Save REF Waveform

After the REF source is selected, press Save to save the waveform (screen region) in the specified source to internal memory as reference waveform and display it on the screen.

Note: This operation only saves the reference waveform in the volatile memory and the waveform will be cleared at power-off.

To Adjust REF Waveform Display

You can adjust the vertical scale and vertical position of the reference waveform specified in Current.

Press Current, use to select any channel currently enabled (Ref1-Ref10). Press

, use to adjust the vertical position of the reference waveform. Press , use to adjust the vertical scale of the reference waveform. Press Reset and the reference waveform returns to the position where the source channel waveform is located when the Save operation was executed.

To Export to Internal or External Memory

Users can save the reference waveform in “*.ref” format to the internal memory or external USB storage device. At most 10 reference files (LocalREF0.ref to

LocalREF9.ref) can be saved inside the instrument.

Press Export to enter the file store interface. Please refer to the relative descriptions in “ Store and Recall” to save the reference waveform to internal or external memory.



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RIGOL Chapter 9 Reference Waveform

To Import from Internal or External Memory

Users can also import the reference waveform stored in the internal memory or external USB storage device to the instrument.

Press Import to enter the file recall interface. Please refer to the relative descriptions in “ Store and Recall” to import the reference waveform to the instrument.

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Chapter 10 Pass/Fail Test RIGOL

Chapter 10 Pass/Fail Test

During the product design and manufacture process, you usually need to monitor the change of the signal or judge whether the product is up to standard. The pass/fail test function of MSO2000A/DS2000A oscilloscope can fulfill this task perfectly.


 To Enable Pass/Fail Test

 To Select Source

 Mask Range

 To Set Test Results Output Type

 To Save the Test Mask

 To Load the Test Mask



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RIGOL Chapter 10 Pass/Fail Test

To Enable Pass/Fail Test

Press Utility  Pass/Fail  Enable to select “ON”. The area covered by blue on the screen denotes the failure area and if the waveform measured at certain time point during the measurement process passes through the failure area, it will be treated as failed frame. Press Operate to select “ ” to start testing and select “ ■ ” to stop testing.

Note: The pass/fail test function is not available in the following status.

 In X-Y time base mode;

 In ROLL time base mode;

 In Y-T time base mode and the horizontal time base is set to 200ms/div or slower, namely the instrument enters “Slow Sweep” mode;

 When the waveform record is enabled;

 None of the analog channels (CH1, CH2) is turned on.

After the pass/fail test is enabled, you can set the output type of the test results according to “To Set Test Results Output Type”. You can also select the signal source, set the test mask range, create mask as well as save and recall the test mask.

For the details, refer to the introductions below.

To Select Source

Press Source to select the channel (CH1 or CH2) to be tested and only channels enabled can be selected.

Mask Range

Users can define their desired test masks. If the waveform passes through the mask range (namely the waveform enters the area covered by blue), it is judged as a failed frame.

Press Range  Range to select “Screen” or “Cursor”. The default is “Screen”.

When “Screen” is selected, press X Mask and Y Mask respectively and rotate to

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Chapter 10 Pass/Fail Test RIGOL adjust the horizontal tolerance range and vertical tolerance range of the test mask.

The horizontal and vertical adjustment ranges are 0.02 div to 4 div and 0.04 div to

5.12 div respectively. During the adjustment, two white curves would be displayed in the interface to show the outline of the current mask. Press Create to apply the mask currently created (the area not covered by blue within the screen), as shown in the figure below.

Figure 10-1 Test Mask (Screen Region)

When “Cursor” is selected, two gray cursor lines appear on the screen (used to indicate the current test mask range); cursor A is on the left and cursor B is on the right. Press CursorA and CursorB respectively and use to adjust the positions of cursor A and cursor B. Or, press CursorAB and use to adjust the positions of cursor A and cursor B at the same time (the horizontal distance keeps unchanged).

Then, adjust the horizontal tolerance range and vertical tolerance range as well as create the mask (the area not covered by blue within the cursor region) by referring to the methods above; as shown in the figure below.

Figure 10-2 Test Mask (Cursor Region)



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RIGOL Chapter 10 Pass/Fail Test

To Set Test Results Output Type

You can set the output type of the test results referring to the following methods.

1.

The Statistic Message

Press Message to select “ON” or “OFF”. When “ON” is selected, the statistic message of the test results (including the number of the failed frames, the passed frames and the total frames) will be displayed at the upper right corner of the screen, as shown in the figure below.

2.

Stop on Fail

Press StopOnFail to select “ON” or “OFF”.

 ON: when a failed waveform is detected, the oscilloscope will stop the test and enter the “STOP” state. At this point, the results of the test remain the same on the screen (if Message is set to “ON”) and only one negative pulse is output from the [Trigger Out] connector (if AuxOutput is set to

“ON”) at the rear panel.

 OFF: the oscilloscope will continue with the test even though failed waveforms are detected. The test results on the screen will update continuously (if Message is set to “ON”) and a pulse will be output from the [Trigger Out] connector (if AuxOutput is set to “ON”) at the rear panel each time a failed waveform is detected.

3.

Beeper on Fail

Press Output to select “Fail” or “Fail+ ”.

 Fail: there is output when a failed waveform is detected; but, the beeper does not sound.

 Fail+ : there is output when a failed waveform is detected and the beeper sounds (not related to the on/off state of the sound) at the same time.

4.

[Trigger Out] Outputs Pulse

Press AuxOutput to select “ON” or “OFF”. If “ON” is selected, the oscilloscope

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Chapter 10 Pass/Fail Test RIGOL outputs a pulse from the [Trigger Out] connector at the rear panel when a failed waveform is detected.

You can also press Utility  AuxOutput and select “PassFail” to set this output.

To Save the Test Mask

Users can save the current test mask in “*.pf” format to the internal Flash memory or external USB storage device. The internal memory can store at most 10 test mask files (LocalPF.pf).

Press Save to enter the file store interface. Please refer to the relative descriptions in

“ Store and Recall” to save the test mask file to the internal or external memory.

To Load the Test Mask

Users can also load the test mask files (*.pf) stored in the internal Flash memory or external USB storage device to the instrument.

Press Load to enter the file recall interface. Please refer to the relative descriptions in “ Store and Recall” to load the test masks to the instrument.



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Chapter 11 Waveform Record RIGOL

Chapter 11 Waveform Record

Waveform record can record the waveforms of the analog channels (CH1 and CH2) and the digital channels (D0-D15). In record constant on (open) mode, the oscilloscope can record the input waveform continuously until users press

RUN/STOP. Waveform playback and analysis can provide better waveform analysis effect.

Note:

1.

The horizontal time base must be set to Y-T mode during waveform record.

2.

The digital channels only support waveform record and waveform playback; they do not support waveform analysis.


 Waveform Record

 Record Constant On

 Waveform Playback

 Waveform Analysis



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RIGOL Chapter 11 Waveform Record

Waveform Record

When the waveform record function is turned on, waveforms from all the channels currently turned on will be recorded. Press Utility  Record  Mode and use to select “Record” to open the waveform record operation menu.

1.

End Frame

Press End Frame; use or the inner knob of the navigation knob to adjust the the desired number of frames to be recorded at a relatively smaller step or turn the outer knob of the navigation knob to adjust the the desired number of frames to be recorded at a relatively larger step. The available range is from 1 to the maximum number of frames that can be recorded currently (displayed in

Total Frames).

2.

Record Operation

Waveform recod can be realized via the menu or the shortcut buttons at the

front panel.

Menu Front Panel

Press Operate and select “ start recoding.

● ” to

Press ; the backlight goes on (in red) and starts to flash, indicating that the record is started.

When the record is finished, “ ● ” changes to “ ■ ” automatically.

You can also select “ ■ ” manually to stop recording.

When the record is finished, goes off automatically and goes on (in orange). You can also press directly to stop recording.

3.

Interval

Press Interval; use or the inner knob of the navigation knob to adjust the time interval at a relatively smaller step or turn the outer knob of the navigation knob to adjust the time interval at a relatively larger step. The range available is from 100 ns to 10 s.

4.

Total Frames

The menu shows the maximum number of frames that can be recorded currently.

The number of points of each frame is the current memory depth [1] . As the

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Chapter 11 Waveform Record RIGOL capacity of the waveform memory is fixed, the more the number of points each frame of waveform has, the less the number of waveform frames can be recorded. Thus, the maximum end frame of waveform record is decided by the memory depth currently selected. Please refer to the instruction in “Memory

Depth” to select the desired memory depth. In addition, the maximum number of frames is also related to the on/off states of the digital channels.

Note [1] : Memory depth = Sample rate × Horizontal time base × Number of grids horizontally on the screen; wherein, for MSO2000A/DS2000A, “Number of grids horizontally on the screen” is 14. Therefore, when the memory depth is set to "Auto", the maximum end frame of waveform record is also related to the “Sample rate” and “Horizontal time base”.

Table 11-1 Memory Depth and Maximum Number of Frames (In this example, only a single channel is turned on)

Memory Depth Maximum End Frame

14 k points None of the digital channels is turned on: 8128

140 k points

1.4M points

One or more digital channels are turned on: 4088

508

63

14M points

56M points

Auto

7

2

Related to the “Sample Rate” and “Horizontal Time Base”



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Record Constant On

MSO2000A/DS2000A provides record “Open” (record constant on) mode for waveform record. When this mode is enabled, the oscilloscope records the waveform continuously according to the current memory depth. The length of the waveform recorded is limited by the memory depth (sample rate and horizontal time base) and the waveform data recorded before will be overwritten by the waveform currently recorded. In this mode, the other oscilloscope operations (except “Pass/Fail Test”,

"Protocol Decoding" as well as “Acquisition Mode” and “Memory Depth” in the sample system setting and “Time Base Mode” in the horizontal system setting) are not affected.

Press Utility  Record  Mode and use to select “Open”. At this point, the waveform record key at the front panel turns red and the oscilloscope records the waveform continuously according to the current memory depth. The oscilloscope stops recording until users press RUN/STOP and at this point, users can play back or analyze the waveform.

In constant on mode, the oscilloscope can capture the accidental abnormal signals during the adjustment. Following is an application example of the record constant on mode. Use MSO2000A/DS2000A (CH1) to observe a pulse which might contain runt pulses.

1.

Connect the pulse under test to CH1 of the oscilloscope. Adjust the oscilloscope to make it trigger stably.

2.

Enable record constant on mode.

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Figure 11-1 Record Constant On

3.

Press RUN/STOP to stop the record.

4.

Analyze the waveform recorded using waveform analysis and as shown in the figure below, the runt pulses are captured.

Figure 11-2 Analyze the waveform recorded



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Waveform Playback

Waveform playback can play back the waveforms currently recorded. After recording the waveforms, press Utility  Record  Mode and use to select “Play back”.

At this point, the information as shown in the figure below is displayed at the upper right corner of the screen, indicating the specific frame currently displayed on the screen. During the playback, this value would change continuously.

Please refer to the following descriptions to set the playback parameters.

1.

Play Mode

Press this softkey to set the playback mode to cycle or single.





: cycle playback. Play from the start frame to the end frame and then repeat until you stop it manually.

: single playback. Play from the start frame to the end frame and then stop.

2.

Interval

Press this softkey and use or the inner knob of the navigation knob to adjust the time interval of playback at a relatively smaller step or turn the outer knob of the navigation knob to adjust the time interval of playback at a relatively larger step. The range availbale is from 100 ns to 10 s and the default is 100 ns.

3.

Start Frame

Press this softkey and use to set the start frame of playback. The default is 1 and the maximum is the maximum number of frames recorded.

4.

Current Frame

Press this softkey and set the current frame using or the navigation knob by referring to the method mentioned above. By default, the current frame is the same with the end frame. The setting range of current frame is related to the start frame and end frame settings. During the setting, the screen will display the corresponding waveform of the current frame synchronously, namely manual playback.

If you perform the playback operation after setting this parameter, this menu will be adjusted to the start frame value automatically and will change continuously

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Chapter 11 Waveform Record RIGOL during the playback process.

5.

End Frame

Press this softkey and use to set the end frame of the playback. The default is the total number of frames of the waveform recorded.

6.

Playback Operation

Waveform playback can be realized through the menu or the shortcut buttons at the front panel.

Menu Front Panel

Press ; the backlight flashes, Press Operate and select “ ” to start playing back.

Press Operate and select “ ” to pause the playback. indicating that the playback is started.

Press again (the backlight goes on

(yellow)) to pause the playback.

Press Operate and select “ ■” stop the playback.

Press to stop the playback.

7.

Time Tag

The time tag is used to display the absolute recording time of each frame of the waveform currently recorded. Press Time Tag to enable or disable the time tag function. When it is enabled, the time tag information is displayed at the upper right corner of the screen as shown in the figure below.

T

0

: display the absolute starting time of the waveform record.

△ T: display the recording time deviation of the current waveform relative to the first frame of waveform. This value changes accordingly during the waveform playback process.

Tip

During waveform playback, RUN/STOP can be used to switch between playback and pause. Each time SINGLE is pressed, the Current Frame moves one frame forward.

11-7 MSO2000A/DS2000A User’s Guide


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Waveform Analysis

This function is used to analyze the recorded waveform. Press Utility  Record 

Mode and use to select “Analyze” to open the waveform analysis menu. At this point, the screen is divided into two display areas as shown in the figure below.

Settings and Results Templet Display Current Frame

Figure 11-3 Waveform Analysis

Please refer to the following explanations to set the waveform analysis parameters.

1.

Analyze

Press Analyze to select the desired analysis mode.

 Trace: perform analysis on the basis of the templet selected by users. For the detailed information, refer to “Analysis Based on Trace”.

 Pass/Fail: perform analysis on the basis of the Pass/Fail mask created by users. For the detailed information, refer to “Analysis Based on

Pass/Fail Mask”.

2.

Source

Press Source to select the channel (CH1 or CH2) to be analyzed.

Note: Only channels currently enabled can be selected.

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3.

Start

Before performing the analysis, please set the templet by referring to “Analysis

Based on Trace” or create the mask by referring to “Analysis Based on

Pass/Fail Mask” according to the analysis mode currently selected. Then, press Start to enable waveform analysis.

Note: During the analysis process, the progress bar is displayed and the parameters cannot be modified.

After the analysis finishes, the analysis results of “Error Frames”, “Current Error” and “CurFrame Diff” are displayed; at the same time, the first error frame is located as shown in the figure below. At this point, the next error frame, the previous error frame as well as every frame in this waveform analysis can be located using the corresponding softkeys.

Error Frames:

The total number of error frames discovered in this analysis. The number of error frames is related to the error frame threshold currently set.

Current Error:

The order number of the error frame lately located in all the error frames when locating every data frame in this analysis.

CurFrame Diff:

During the analysis based on trace, the oscilloscope compares each frame with the templet to compute the difference value and normalizes each value using the maximum one; then, compares the normalized value of each frame with the threshold selected to judge whether the frame is an error frame. “CurFrame

Diff” (relative difference) is the normalized value of the difference between the current frame and templet.

During the analysis based on pass/fail mask, the oscilloscope compares each frame with the mask to compute the difference value and recognizes the frame



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RIGOL Chapter 11 Waveform Record whose difference value is equal to or larger than the threshold selected as an error frame and the corresponding “CurFrame Diff” is 100%; otherwise, the frame is judged as correct and the “CurFrame Diff” is 0%.

Note: There are only two “CurFrame Diff” values (100% and 0%) under the analysis based on pass/fail mask.

4.

Cancel

During the analysis, users can press Cancel to stop the analysis and press Start again to restart the analysis.

5.

Previous

After the waveform analysis finishes, pressing Previous can locate the error frame previous to the current error frame. Pressing RUN/STOP can also perform the operation.

6.

Next

After the waveform analysis finishes, pressing Next can locate the error frame following the current error frame. Pressing SINGLE can also perform the operation.

7.

Current Frame

Press Current Frame; use or the inner knob of the navigation knob to adjust the data frame currently displayed at a relatively smaller step or turn the outer knob of the navigation knob to adjust the data frame currently displayed at a relatively larger step. The adjustable range is from 1 to the total number of frames in this waveform analysis. Using the navigation knob can also perform the operation.

8.

Setup

Press Setup to open the more detailed setting menu.

 Screen Start: press this key to set the start point of waveform analysis and the range is from 5 to 685. The start point must be less than the “Screen

End - 10” currently set.

 Screen End: press this key to set the end point of waveform analysis and the range is from 15 to 695. The end point must be greater than the

“Screen Start + 10” currently set.

 Start Frame: press this key to set the start frame of waveform analysis

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(refer to the setting method of the current frame mentioned above) and the default is the first frame.

 End Frame: press this key to set the end frame of waveform analysis (refer to the setting method of the current frame mentioned above) and the default is the last frame.

 Threshold: press this key to set the threshold of waveform analysis and the range is from 1% to 99%. The threshold is used to judge whether the frame is an error frame. A frame is recognize as an error one if the (relative) difference value between the frame and the templet is equal to or larger than the threshold currently set.

9.

Time Tag

The time tag is used to display the absolute recording time of each frame of the waveform currently recorded. Press Time Tag to enable or disable the time tag function. When it is enabled, the time tag information is displayed at the upper right corner of the screen as shown in the figure below.

T

0

: display the absolute starting time of the waveform record.

△ T: display the recording time deviation of the current waveform relative to the first frame of waveform.



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Analysis Based on Trace

Press Analyze and select “Trace”. Then, set the templet used in analysis based on trace through the method below.

1.

Trace

Press Trace to select the creation method of analysis templet.

 Current Frame: select the current frame as the analysis templet.

 Average: select the average of the current data frame as the analysis templet.

2.

Setup Template

Press SetupTemplate to configure the templet immediately. After the analysis starts, the oscilloscope compares each frame with the templet and determines whether error frame exists according to the threshold currently set.

3.

TemplateDisp

Press TemplateDisp to enable or disable templet display.

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Analysis Based on Pass/Fail Mask

Press Analyze and select “Pass/Fail”. Then, set the templet used in analysis based on Pass/Fail mask through the method below.

Press Range to open the mask range setting menu. Please refer to the introduction in “ Mask Range” to create the test mask used in waveform analysis.

Besides, you can store the current test mask in “*.pf” format into the internal memory or external USB storage device or load the test mask file stored in the internal memory or external USB storage device into the instrument. Press Save to enter the file store interface. Store the test mask file to internal or external memory by referring to the introduction in “Store and Recall”. Press Load to enter the file recall interface. Load the test mask into the instrument by referring to the introduction in “Store and Recall”.



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Chapter 8 Protocol Decoding. Rigol DS2000A Series, MSO2000A Series

To Use the Digital Bus

To Set the Label

Digital Channel Delay Calibration

Chapter 8 Protocol Decoding

Parallel Decoding

RS232 Decoding (Option)

I2C Decoding (Option)

SPI Decoding (Option)

CAN Decoding (Option)

Chapter 9 Reference Waveform

To Enable REF Function

To Set the Color

To Select REF Source

To Save REF Waveform

To Adjust REF Waveform Display

To Export to Internal or External Memory

To Import from Internal or External Memory

Chapter 10 Pass/Fail Test

To Enable Pass/Fail Test

To Select Source

Mask Range

To Set Test Results Output Type

To Save the Test Mask

To Load the Test Mask

Chapter 11 Waveform Record

Waveform Record

Record Constant On

Waveform Playback

Waveform Analysis

Analysis Based on Trace

Analysis Based on Pass/Fail Mask

Related manuals

Table of contents

Chapter 8 Protocol Decoding. Rigol DS2000A Series, MSO2000A Series

To Use the Digital Bus

To Set the Label

Digital Channel Delay Calibration

Chapter 8 Protocol Decoding

Parallel Decoding

RS232 Decoding (Option)

I2C Decoding (Option)

SPI Decoding (Option)

CAN Decoding (Option)

Chapter 9 Reference Waveform

To Enable REF Function

To Set the Color

To Select REF Source

To Save REF Waveform

To Adjust REF Waveform Display

To Export to Internal or External Memory

To Import from Internal or External Memory

Chapter 10 Pass/Fail Test

To Enable Pass/Fail Test

To Select Source

Mask Range

To Set Test Results Output Type

To Save the Test Mask

To Load the Test Mask

Chapter 11 Waveform Record

Waveform Record

Record Constant On

Waveform Playback

Waveform Analysis

Analysis Based on Trace

Analysis Based on Pass/Fail Mask

Related manuals

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MSO2302A-S

Rigol

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Rigol

DS2000A Series

Rigol

DS2000A Series

Rigol

DSG3136B-IQ

BK Precision

2190E

BK Precision

4064

Cal Test Electronics

CT4196

Rigol

DS2000 Series

Table of contents