Power Meter Operation
Zeroing and Calibrating the Power Meter
Agilent E4419B User’s Guide 2-15
Table 2-4:  TTL Inputs Timing Diagram 2
Timing of zero/cal inputs for condition “00”.
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 
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.
4 s
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.
Inputs
Operation
T5
T6
T7
T8
HP4402.book  Page 15  Thursday, November 30, 2000  1:39 PM