CB-7080 & CB-7080D Counter/Timer User's Guide
Application
notes
1-9
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:
Table 1-5: Preset values
Factory default setting
Counter preset value is 0
Power on state
Counters 0/1 are set to the preset value
$AA6N
Counter N is set to the preset value
$AAPN(data)
Sets the preset value of counter N
Frequency input applications
To set the module to frequency mode set the configuration code to
51
in the Set module configuration
command.
Table 1-6. Frequency mode settings
Command
Result - Frequency 0
Result - Frequency 1
$AAB0 to set input mode 0
$AA1H(data) and $AA1L(data)
Non-isolated channel 0 and
threshold voltage values active
Non-isolated channel 1 and
threshold voltage values active
$AAB1 to set input mode 1
Isolated channel 0
Isolated channel 1
$AAB2 to set input mode 2
$AA1H(data) & $AA1L(data)
Non-isolated channel 0 and
threshold voltage values active
Isolated channel 1
$AAB3 to set input mode 3
$AA1H(data) & $AA1L(data)
Isolated channel 0
Non-isolated channel 1 and
threshold voltage values active
To measure frequency:
1.
Use the $AA1H(data) and $AA1L(data) commands to set the threshold voltage values, if the frequency
input is a non-isolated input.
2.
Use the $AAB? command to select the mode (this command will clear the current frequency first).
3.
Use the #AA? command to perform frequency measurement.
Only four commands are important in frequency measurement mode:
$AAB?
Select mode
$AA1H(data)
Set high-level threshold value
$AA1L(data)
Set low-level threshold value
#AA?
Perform frequency measurement
The status-read-back commands are:
$AAB?
Mode read back
$AA1H
High_level threshold value read back
$AA1L(data)
Low_level threshold value read back
