It is not obvious from the documentation what IPMI commands are supported by Zabbix.
It seems that only "Basic controls" are supported:
Where <value> is an integer resp. "on" or "off" and <command> is (theoretically) one of these:
- fan speed
- one-shot reset
- one-shot output
Since blanks are not supported for commands, commands like "fan speed" can neither be used.