Local Operation 
 
M370430-01  Rev B  3-25 
Alarm Output Latching 
When an alarm is triggered, the output will be disabled with the 
exception of the Fan alarm. When an alarm is cleared, the alarm output 
latch determines if the output should be re-enabled to the state before the 
alarm occurred or if the output should remain in the off state. 
Where setting the bit position (1) of an alarm latch will result in output 
latching to the off state when the alarm is cleared and if cleared (0) 
output will be re-enabled to the state before the alarm triggered. 
To define the values for the bit position you determine which alarms you 
want to latch. Read the value for this bit position from Table 3-6 and 
sum them together. The result is the alarm last mask, which you should 
send with the SCPI command. 
For Example: 
If you wanted to enable latching for OTP and Foldback you would take 
the OTP value of 2 and add it to the foldback value of 256 to get a mask 
of 258. This is the value you would send with the SCPI command. 
The output latches are accessible through the SCPI command. 
The SCPI command (s) for these instructions are: 
[:]SYSTem[<channel>]:PROTection:LATCh 
The latch command take a single decimal parameter made up of the sum 
of the values for the alarms to determine if they are to be latched in the 
off state on clearing. See Table 3-6 for the values associated with each 
latchable alarm. 
Table 3-6  Alarm Latch Bit Positions  
Over Temperature Protection (OTP) 
Over Temperature Protection (OTP) Slave 
(1700 Watt only)