Measurement Computing CB-COM-7021 - Manual (Page 70)

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CB-7021, CB-7022, CB-7024 User’s Manual
is set to Safe Value. When the module receives the output command,
such as #AA(Data) or #AAN(Data), the module will returns ignore
(receive:!) and will not change the output to the output command
value. The host watchdog timeout status is set and stored in
EEPROM while the host watchdog timeout interval expired,
and can only be cleared by command ~AA1.
If the user wants to
change the output, he must first clear the host watchdog timeout
status, then send an output command to change the output to the
desired value.
<2> PowerOn Value. When the module is reset, and/or
when the host watchdog timeout status is clear, the module’s output
is set to predefined PowerOn Value.
<3> Output Command Value. When the host watchdog
timeout status is clear , the user sends command #AA(Data) or
#AAN(Data), to the module to change the output value. The module
will returns successful (receive >). If user sets the output value over
the maximum value of output range, the output will go to maximum
value and returns an out-of-range (receive ?AA) reply. If the output
value is under the minimum value of output range, the output will
go to minimum value and returns out-of-range
(receive ?AA).
3.6 Slew Rate Control
Slew rate control is used to adjust the output rate-of-change.
Most analog output changes are step-changes. In many
applications, this characteristic is undesirable. A gradual output
change under slew rate control is more appropriate.