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Insertion loss
Insertion loss is AC signal power lost between the input and the output. In general, as frequency
increases, insertion loss increases.
For the 7710 card, insertion loss is specified for a 50Ω AC signal source routed through the mod-
ule to a 50Ω load. Signal power loss occurs as the signal is routed through the signal paths of the
module to the load.
Insertion loss is expressed as dB magnitudes at specified frequencies. The specifications for inser-
tion loss are provided in the "Specifications" at the end of this User's Guide. (See INSERTION
LOSS in the "Specifications".)
As an example, assume the following specifications for insertion loss:
<1dB @ 500kHz
<3dB @ 2MHz
As signal frequency increases, power loss increases.
NOTE
Crosstalk
An AC signal can be induced into adjacent channel paths on the 7710 card. In general, crosstalk
increases as frequency increases.
For the 7710 card, crosstalk is specified for an AC signal routed through the module to a 50 Ω load.
Crosstalk is expressed as a dB magnitude at a specified frequency. The specification for crosstalk
is provided in the "Specifications" at the end of this User's Guide. (See CROSSTALK in the
"Specifications".)
As an example, assume the following specification for crosstalk:
<-40dB @ 500kHz
As signal frequency increases, crosstalk increases.
NOTE
Additional errors for 27xx switch systems
Additional 27xx measurement errors and typical system scanning speeds are provided after the
first page of the "Specifications" on
specifications of the Model 27xx mainframe being used in the switch system.
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12
1dB insertion loss is approximately 20% loss of signal power.
3dB insertion loss is approximately 50% loss of signal power.
The insertion loss values used in the above example may not be the actual insertion
loss specifications of the Model 7710. The actual insertion loss specifications are
provided in the "Specifications" at the end of this User's Guide.
-40dB indicates that crosstalk into adjacent channels is 0.01% of the AC
signal.
The crosstalk values used in the above example may not be the actual crosstalk
specification of the Model 7710. The actual crosstalk specification is provided in the
"Specifications" at the end of this User's Guide.
Notes 1, 2 and 3 (and tables) for "DC CHARACTERISTICS" pertain to additional errors
for high-ohms resistance measurements, voltage measurements, and temperature mea-
surements.
The two tables for "SYSTEM SPEEDS" provide speed data for scanning. For the various
scan functions, the tables list the fundamental reading rate setting (in PLCs) and typical
speed (in readings per second) into and out of memory.
page
23. These measurement errors are to be added on to the
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