MDO3000 Programmer Manual.pdf - 第107页

Command Groups T o set up a logic trigger , ﬁrst set the trigger type to LOGIc using the command TRIGger:A:TYPe , and then use the comma nd TRIGger:A:LOGIc:CLAss to select LOGIC . Y ou can perform logic triggering using …

Command Groups

Trigger Comma

nd Group

Use the commands in the Trigger Command Group to control all aspects of

triggering the oscilloscope. You can perform edge, pulse width, logic, video, runt,

timeout, tra

nsition (rise/fall time), setup & hold and bus triggering using the A

trigger. You can perform sequence edge triggering using the A and B triggers.

The MDO4000/B/C allows you to use a change in the RF power level as a source

for edge triggering. Using an MDO4000/B/C oscilloscope with a MDO4TRIG

application module installed, a changeintheRFpowerlevelcanalsobeusedasa

source for pulse width, timeout, runt, logic and sequence triggers.

With the MDO4000/B/C, the acquisition system is fully integrated with boththe

time and frequency domain channels. This means

that a single event triggers

all of the analog, digital and RF acquisitions, regardless of where that trigger

event came from.

NOTE. MDO3000 models only have two digital threshold controls: o ne for d igital

channels D0 - D7, and the other for D8 - D15. Digital channel trigger levels

cannot be set independently for these models. Changing one digital channel’s

threshold level changes all of the channels

’ levels in the same set.

Example command sequences that show different triggers and searches are

available. (See page F-1, Search and Trigg

er Command Sequence Examples.)

Edge Trigger

Edge triggering lets you display a waveform at or near the point where the signal

passes through a voltage level of your choosing.

To set up an edge trigger, set the A trigger type to

EDGe using the command

TRIGger:A:TYPe. Then use the commands TRIGger:A:EDGE:COUPling,

TRIGger:A:EDGE:SLOpe,andTRIGger:A:EDGE:SOUrce You can

set the threshold voltage levels using TRIGger:A:LEVel:AUXin,

TRIGger:A:LEVel:CH<x>,orTRIGger:A:LEVel:D<x>.

Using an MDO4000/B/C oscilloscope, you can use the RF power level as a source

in an edge trigger without installing an MDO4TRIG application module. To do

this, set the oscilloscope to trigger on a rising edge with the RF power levelasthe

source, in order to trigger on events where the RF turns on. Conversely, set it to

trigger on a falling edge in order to trigger on events where the RF turns off.

Logic Trigger

Logic triggering lets you logically combine the signals on one or more channels;

the oscilloscope then triggers when it detects a certain combination of signal

levels (set using one of the

TRIGger:A:LOGIc:INPut commands as well as

TRIGger:A:LOGIc:FUNCtion). Using an MDO4000/B/C oscilloscope with an

MDO4TRIG application module installed, you can use the RF power level as a

source in a logic trigger.

2-76 MDO4000/B/C, MSO/DPO4000B and MDO3000 Series Oscilloscopes Programmer Manual

Command Groups

To set up a logic

trigger, ﬁrst set the trigger type to

LOGIc using the command

TRIGger:A:TYPe, and then use the command TRIGger:A:LOGIc:CLAss to

select

LOGIC.

You can perform logic triggering using a clock (by setting TRIGger:A:LOGIc:

INPut:CLOCk:SOUrce to one of the channels), so that the oscilloscope triggers

when the speciﬁed logical combination of data channels is true during a

transition on the clock channel. The speciﬁed data sources cannot include the

waveform speciﬁed as the clock source. (Use TRIGger:A:LOGIc:INPut:CH<x>,

TRIGger:A

:LOGIc:INPut:D<x>,etc.)

You can also perform logic triggering without using a clock (by

setting T

RIGger:A:LOGIc:INPut:CLOCk:SOUrce to

NONE), so that the

oscilloscope triggers when the speciﬁed logical pattern of data channels

is met. (Use the commands TRIGger:A:LOGIc:PATtern:WHEn and

TRIGger:A:LOGIc:PATtern:DELTatime.)

Setup and Hold Trigger

A setup and hold trigger occurs when a logic data input changes state inside of the

setup or hold time relative to a clock edge.

To set up a setup/hold trigger, ﬁrst set the trigger type to

LOGIc using the command

TRIGger:A:TYPe, and then use the command TRIGger:A:LOGIc:CLAss

to select

SETHold.ThenuseTRIGger:A:SETHold:DATa:SOUrce,

TRIGger:A:SETHold:CLOCk:SOUrce, TRIGger:A:SETHold:CLOCk:EDGE

and related commands.

Pulse width Trigger

A pulse width trigger occurs whenever the oscilloscope detects a pulse thatis

less than, greater than, equal to, or not equal to a speciﬁed time. Additionally,

it can occur when the pulse width is within, or outside of a speciﬁed range.

ou can trigger on either positive or negative pulses. Using an MDO4000/B/C

oscilloscope with an MDO4TRIG application module installed, you can use the

RF power level as a source in a pulse width trigger.

To set up a pulse width trigger, ﬁrst set the trigger type to

PULSe using

the command TRIGger:A:TYPe. Then select

WIDth using the command

TRIGger:A:PULse:CLAss.ThenuseTRIGger:A:PULSEWidth:SOUrce,

TRIGger:A:PULSEWidth:WHEn, TRIGger:A:PULSEWidth:WIDth and related

commands. You can set the threshold voltage levels using TRIGger:A:LEVel:

AUXin, TRIGger:A:LEVel:CH<x>,orTRIGger:A:LEVel:D<x>.

Runt Trigger

Runt triggering lets you trigger on a pulse amplitude that crosses one threshold

but fails to cross a second threshold before recrossing the ﬁrst. Using an

MDO4000/B/C oscilloscope with an MDO4TRIG application module installed,

you can use the RF power level as the source in a runt trigger.

MDO4000/B/C, MSO/DPO4000B and MDO3000 Series Oscilloscopes Programmer Manual 2-77

Command Groups

To set up a runt t

rigger, ﬁrst set the trigger type to

PULSe using the

command TRIGger:A:TYPe. Then select

RUNt using the command

TRIGger:A:PULse:CLAss.ThenuseTRIGger:A:RUNT:SOUrce,

TRIGger:A:RUNT:WIDth, TRIGger:A:RUNT:WHEn, TRIGger:A:

UPPerthreshold:CH<x> and related commands. You can set the threshold

voltage levels using TRIGger:A:LEVel:AUXin, TRIGger:A:LEVel:CH<x>,or

TRIGger:A:

LEVel:D<x>.

Timeout Trigger

Timeout triggering causes a trigger when a signal stays above or below a speciﬁed

threshold for a speciﬁed amount of time. Using an MDO4000/B/C oscilloscope

with an MDO4TRIG application module installed, you can use the RF power

level as a source in a timeout trigger.

To set up a timeout trigger, ﬁrst set the trigger type to

PULSe using the

command TRIGger:A:TYPe. Then select

TIMEOut using the command

TRIGger:A:PULse:CLAss.ThenuseTRIGger:A:TIMEOut:SOUrce,

TRIGger:A:TIMEOut:TIMe and related commands.

Transition Trigger

Transition triggering (also called rise/fall time, and once known as slew rate)

causes a trigger on pulse edges that traverse between two thresholds at a rate faster

than or slower than the speciﬁed time.

To set up a transition trigger, ﬁrst set the trigger type to

PULSe using the command

TRIGger:A:TYPe.Thenselect

TRANsition using the command TRIGger:

A:PULse:CLAss.ThenuseTRIGger:A{:TRANsition|:RISEFall}:SOUrce,

TRIGger:A{:TRANsition|:RISEFall}:DELTatime and related commands.

You can set the threshold voltage levels using TRIGger:A:LEVel:AUXin,

TRIGger:A:LEVel:CH<x>,orTRIGger:A:LEVel:D<x>.

Bus Trigger

Bus triggering can be performed if you have one or more appropriate application

modules installed (see below for application module list), except for parallel bus

trigger and analysis, which is included standard with the MSO and MDO Series.

To set up a bus trigger, set the A trigger type to

BUS using the command

TRIGger:A:TYPe. Specify which bus (1-4) to trigger on using

TRIGger:A:BUS:SOUrce. Set the bus type (i.e., parallel, I

C, etc. using the

command TRIGger:A:BUS. Then set the appropriate trigger criteria according to

bus type (using TRIGger:A:BUS:B<x>:AUDio:CONDition,etc.)

Video Trigger

Video triggering enables you to trigger on the most common Standard Deﬁnition

video standards. With the DPO4VID module installed, you can also trigger on

the most common HDTV standards and non-standard video (bi-level sync and

trilevel sync). This feature is standard for the MDO3000 and MDO4000C series

models and does not require a module.

2-78 MDO4000/B/C, MSO/DPO4000B and MDO3000 Series Oscilloscopes Programmer Manual