Power Meter Operation

Zeroing and Calibrating the Power Meter

Table 2-4: TTL Inputs Timing Diagram 2

Timing of zero/cal inputs for condition “00”.

Inputs

Operation

T5

T6

T7

T8

Time

Description

Value

 

 

 

T5

Maximum time between inputs going low.

100 ms

 

 

 

T6

Minimum overlap of low inputs.

200 ms

 

 

 

T7

Time between input detection and start of zero/cal

4 s

 

cycle. This is determined by the number of

 

 

averages x sample rate, or if there is an existing

 

 

zero/cal operation in progress, the time for this

 

 

current operation to complete. Note that the

 

 

worst case is 1024 averages x 50 ms = 51.2 s. For

 

 

front panel operation (in free run mode) the time

 

 

is 1 x 50 ms.

 

 

 

 

T8

Time for cal operation to complete.

Cal: 6 s (8480 series)

 

 

7 s (E series)

 

 

 

All timings based on 100 ms firmware polling.

If both TTL inputs are simultaneously low under any circumstances other than those shown above, the operation is undefined.

HP E4419B User’s Guide

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