HP 53131A Operating Manual page 160

Table 2-7A. HP 53131A (and HP 53132A With S/N Prefix Below 3646) Preset Values (continued)
Description
Calibration Security Parameters
Secure state
Security code
Calibration count
Chapter 2 Operating Your Universal Counter
Preset Values After Power-Up and *RST
In
Save/Recall
no
no
no
1
At power-up, the trigger level is defaulted. The default value is shown in the table. The Counter retains this
value until the first auto-trigger cycle runs. Since the Counter powers up on Run mode with auto-trigger ON,
the auto-trigger cycle runs almost immediately. The default value is overwritten by a measured result almost
immediately.
At *RST, the trigger level variable is defaulted. The default value is shown in the table. Same as for power-up,
the Counter retains this value until the first auto-trigger cycle runs. However, on *RST, the Counter is set up in
Single mode, (not Run mode), with auto-trigger ON. The auto-trigger cycle runs only on initiation of a
measurement. The default value for the variable persists until overwritten by a measured result, but it may be
a long time before you request a measurement; therefore, it may be a long time that the default value
persists.
2
At power-up, you can bring up the Counter either in the Utility menu, or in the results display. The default
behavior of the Run/Single variable differs according to that choice.
When the Counter powers up in the result display, it powers up in Run mode and begins making
measurements immediately.
The Counter does not make measurements when the Utility menu is selected. (This is to reduce confusion
while the user configures major attributes of the instrument.) When you power up on the Utility menu, the
Counter is in Single. Upon exit of the Utility menu, the Counter transitions to Run automatically.
3
At *RST and at power-up, this value is undefined. The frequency-estimation routine, ("auto-frequency"
routine), is enabled. When you select auto-frequency OFF, and provide a value, the variable takes on that
value.
4
Fundamental instrument settings are stored in non-volatile RAM. These settings persist even if the Counter is
powered down and back up again. They persist if the Counter is reset over HP-IB with *RST. You can change
these settings, and the changed value is stored so that it is unaffected if the Counter is powered down or
reset over HP-IB with *RST.
The default values for these special features are indicated in the table. The default values are used when
new EPROMs are installed; they remain in effect until you overwrite them.
An example is the trigger calibration setting. Calibration values are defaulted until calibration is performed at
the factory. Another example is the RS-232 BAUD rate. BAUD rate is defaulted until you pick a different rate.
2-84
Value at *RST Value at
(HP-IB Reset) Power-Up
4
________ ________
4
________ ________
4
________ ________
In
Non-Volatile
Memory
4
yes, (SECURE)
yes, (53131 or
4
53132)
4
yes, (0)
Operating Guide