Agilent Technologies E4418B User Manual page 55

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".
Input
Operation
Time
T1 Minimum width of input
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.
T3 Maximum width of input. Longer inputs may cause a
subsequent zero/cal operation some time after the current
one is complete.
T4 Time for zero/cal operation to complete.
Agilent E4418B User's Guide
Zeroing and Calibrating the Power Meter
T1
T2
T3
T4
Description
All timings based on 100 ms firmware polling.
Power Meter Operation
Value
300 ms
Max: 50 ms (typical)
Min: 0 ms
4 s
Zero: 10 s (8480 series)
12 s (E series)
Cal: 6 s (8480 series)
7 s (E series)
2-13