Preset Value Setting; Frequency Input Applications - Measurement Computing CB-7080 User Manual

CB-7080 & CB-7080D Counter/Timer User's Guide
Gate control setting
The gate control is ignored in frequency mode (51). The gate control is disabled in counter mode (50) by
default. Use the following commands to enable/disable the gate control:
When you use the $AAA0 command, the gate input must be low to enable the counter.
When you use the $AAA1 command, the gate input must be high to enable the counter.
When you use the $AAA2 command, the gate input is disabled. The counter is always enabled.

Preset value setting

The preset value is ignored in frequency mode (51). The counters go to their preset value in the first power-on
state. The reset counter command, $AA6N, also forces the counters to go to their preset value. The default
preset value is 0. Use the $AAPN(data) command to change the preset value. The key points include:
Factory default setting
Power on state
$AA6N
$AAPN(data)

Frequency input applications

To set the module to frequency mode set the configuration code to 51in the Set module configuration
command.
Command
$AAB0 to set input mode 0
$AA1H(data) and $AA1L(data)
$AAB1 to set input mode 1
$AAB2 to set input mode 2
$AA1H(data) & $AA1L(data)
$AAB3 to set input mode 3
$AA1H(data) & $AA1L(data)
To measure frequency:
Use the $AA1H(data) and $AA1L(data) commands to set the threshold voltage values, if the frequency
1.
input is a non-isolated input.
Use the $AAB? command to select the mode (this command will clear the current frequency first).
2.
3. Use the #AA? command to perform frequency measurement.
Only four commands are important in frequency measurement mode:
$AAB?
$AA1H(data)
$AA1L(data)
#AA?
The status-read-back commands are:
$AAB?
$AA1H
$AA1L(data)
Table 1-5: Preset values
Counter preset value is 0
Counters 0/1 are set to the preset value
Counter N is set to the preset value
Sets the preset value of counter N
Table 1-6. Frequency mode settings
Result - Frequency 0
Non-isolated channel 0 and
threshold voltage values active
Isolated channel 0
Non-isolated channel 0 and
threshold voltage values active
Isolated channel 0
Select mode
Set high-level threshold value
Set low-level threshold value
Perform frequency measurement
Mode read back
High_level threshold value read back
Low_level threshold value read back
1-9
Application notes
Result - Frequency 1
Non-isolated channel 1 and
threshold voltage values active
Isolated channel 1
Isolated channel 1
Non-isolated channel 1 and
threshold voltage values active