Multiple Module Synchronous Trigger Timing; Cable Length And Skew - Keysight Technologies N8241A User Manual

Figure 3-10

Cable Length and Skew

Multiple Module Synchronous Trigger Timing Diagram
The cabling requirements are as follows:
Sample Clock
Skew less than 10 mm between modules. The absolute SYNC cable length is
Equation
given by the
Sample Clock Skew Formula
[ n (
Length =
Expressed in mm, where n is an arbitrary integer and f is the sample clock
frequency in MHz.
It should be noted that n is the number of 1/2 SYNC clock cycles of total delay
between the modules.
This can also be expressed in terms of delay:
Cabledelay
Expressed in nanoseconds, where n is an arbitrary integer and f is the sample
clock frequency in MHz.
For the external Sample clock the formulas apply over the frequency range of
625 MHz to 1.25 GHz
Marker and Trigger Cables
The Marker Out to Trigger In cable should be less than 305 mm (12 in). With the
1.25 GHz internal clock, the trigger is falling edge triggered.
Chapter 3
Multiple Module Synchronization
as a function of the Sample clock frequency:
× × ( ) f ) ⁄
686 1250MHz –
( × × (
= n 3.29 1250MHz
Theory of Operation
]
394
) f ⁄ ) 1.89
–
91