HP E4418B User Manual page 53

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.
All timings based on 100 ms firmware polling.
HP E4418B User's Guide
Zeroing and Calibrating the Power Meter
T1
T2
T3
T4
Description
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