EASY-DRIVER – User’s Manual
51
“MWI” Command
The ‘MWI’ command can be used to set the output current value and it is used
when fast set-point changes are needed.
The use of this command is alternative to the MRM (Module RaMping): the
power supply reaches the desired output current value just using the PID regulator
parameters, without ramping with the pre-defined slew rate to the new set-point.
This command is usually needed when running feedback-related applications
and for small changes in the output current.
The correct form format for this command is as follows:
MWI:
value
\r
where:
-
value
is the desired output current value [A].
Replies from the power supply are in the form ‘#AK\r’, or ‘#NAK\r’; this non-
acknowledgment reply is generated, as it is for the MRM command, when:
•
the set
value
is out-of-range (the maximum settable current value is user-defined
and stored in EEPROM cell 4);
•
the module is OFF (it is necessary to turn the module ON first);
Examples:
MWI example with the module OFF:
MWI:-2.5569
\r
#NAK
\r
MWI example with the module ON and already regulating:
MWI:3.50
\r
#AK
\r
It is very important to notice that, even if the module is ON and regulating the
output current correctly, an MWI command can generate a voltage clamping
intervention if the current change step is too large and the PID parameters are not
well matched for the particular load.
