CCS Standardfunction   TimeA [s] (period)
 

TimeA [s] (period)

MaxSignalAmplitude [V]

First TriggerEdge [p/n]

First TriggerLevel [V],

Second TriggerEdge [p/n]

Second TriggerLevel [V]

Hold-off [s]

Timeout [s]

Mode [m/s]

Description of Function

Measurement of duration of a positive or negative pulse or period. Depending on mode, this function acts as a control function or a measurement function.

Testing Points

Test point + Reference point

Parameters

MaxSignalAmplitude

Largest amplitude occurring on the signal. Can be used to establish the measurement range or to select a suppressor circuit.

First TriggerEdge

Specification of which signal edge is to act as trigger for the start of the measurement (p = positive edge, n = negative edge). The preferred option for period measurement is the negative edge.

First TriggerLevel

Trigger level for start of measurement relative to the Ground potential applicable for this signal.
For standard value with positive or negative pulse, see Example 1 Beispiel1_TimeA
 For standard value for period duration, see Example 2 Beispiel2_TimeA

Second TriggerEdge

Specification of which signal edge is to act as trigger for the end of the measurement (p = positive edge, n = negative edge).

Second TriggerLevel

Trigger level for measurement relative to the Ground potential applicable for this signal.
For standard value with positive or negative pulse, see Example 1 Beispiel1_TimeA
 For standard value for period duration, see Example 2 Beispiel2_TimeA

Hold-off

Period after the start of the measurement (triggered by First TriggerEdge) within which the trigger for ending the measurement (Second TriggerEdge) is not accepted. The purpose of this is to prevent false triggering by sporadic interference pulses on the signal (e.g. due to switch bounce).

Note: the hold-off period can not be implemented with all timers. It is not specified in the MSL Catalogue.

Timeout

If the test function receives no measured reading input within the period specified for the timeout, the measurement is aborted.
Standard value: 1s

Mode

The Mode indicates whether the function returns a result (m) or whether the testing instrument is simply prepared for the test (s). Mode m can only be used with periodic test signals. In the case of non-periodic test signals, the test signal is applied and the testing instrument prepared (modes).  The trigger event can then be activated and afterwards the test read function RTimeA IDH_RTimeA invoked.

Example 1

TimeA

15,p,7,n,6,1E-3,1,m


Diagram:


Ulow

Low potential of test signal

Uhigh

High potential of test signal

UTr,n

Trigger level, negative edge

UTr,p

Trigger level, positive edge

tHO

Hold-off period

tp

Pulse width

Figure 8: Pulse duration measurement

For triggering by the edges of a signal pulse, the following applies:

Trigger level: UTr,p = 0.5(Uhigh - Ulow) + Ulow
UTr,n = 0.4(Uhigh - Ulow) + Ulow

Example 2

Period

15,n,7,n,8,1E-3,1,m


Diagram:



Ulow

Low potential of test signal

Uhigh

High potential of test signal

UTr,n1

Trigger level, 1st negative edge

UTr,n2

Trigger level, 2nd negative edge

tper

Period duration

Figure 9: Duration of injection period

For triggering by the negative edge for measuring period duration, the following applies:

Trigger level: UTr,n1 = 0.5(Uhigh - Ulow) + Ulow
UTr,n2 = 0.6(Uhigh - Ulow) + Ulow

For triggering by the positive edge for measuring period duration, the following applies:

Trigger level: UTr,p1 = 0.6(Uhigh - Ulow) + Ulow
UTr,p2 = 0.5(Uhigh - Ulow) + Ulow