Agilent Technologies E4418B, User Manual

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2 Power Meter Operation
36 E4418B Power Meter User’s Guide
Effective control of the zero and calibration cycles using the TTL inputs
depends on correct timing of the input signals as shown in
Table 2- 3 and
Table 2- 4 .
Table 2-3 TTL Input Timing Diagram 1
Timing of zero/cal inputs for conditions “01” and “10”.
Time Description Value
T1 Minimum width of input 300 ms
T2 Time between input detection and start of zero/cal
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. Max: 50 ms (typical)
Min: 0 ms
T3 Maximum width of input. Longer inputs may cause a
subsequent zero/cal operation some time after the
current one is complete. 4 s
T1
T2
T3
T4
Input
Operation