Specifications
User Manual 301/302 
*RST - Resets the generator to its default state. Default values are listed in 
Table 4-1. 
*SRE <enable_value> - Enables bits in the Status Byte enable register. 
*SRE? - Query the Status Byte enable register. The generator returns a 
decimal value in the range of 0 to 63 or 128 to 191 since bit 6 (RSQ) 
cannot be set. The binary-weighted sum of the number represents the 
value of the bits of the Service Request enable register. 
*STB? - Query the Status Byte summary register. The *STB? command is 
similar to a serial poll but is processed like any other instrument command. 
The *STB? command returns the same result as a serial poll, but the 
"request service" bit (bit 6) is not cleared if a serial poll has occurred. 
*TRG - Triggers the generator from the remote interface. This command 
effects the generator if it is first placed in the Trigger or Burst mode of 
operation and the trigger source is set to "BUS". 
*TST? - Implements an internal self-test and returns a value as described 
below. Approximately 90% of the Model 301/302 functionality is tested. 
 0 - Selftest passed 
 1 - CPU to peripherals communication failure 
 2 – Channel A failure 
 4 – Channel B failure 
 8 – Sequence generator failure 
More than one failure can be reported at one time. For example, the 
returned value “17” indicates both a TBD problem and a TBD problem 
exist. 
*WAI – Wait for all pending operations to complete before executing any 
additional commands over the interface. 
The SCPI Status 
Registers
The Model 301/302 uses the Status Byte register group and the 
Standard Event register group to record various instrument conditions. 
Figure 4-1 shows the SCPI status system. 
An Event Register is a read-only register that reports defined 
conditions within the generator. Bits in an event register are latched. 
When an event bit is set, subsequent state changes are ignored. Bits 
in an event register are automatically cleared by a query of that 
register or by sending the *CLS command. The *RST command or 
device clear does not clear bits in an event register. Querying an 
event register returns a decimal value, which corresponds to the 
binary-weighted sum of all bits, set in the register. 
An Event Register defines which bits in the corresponding event 
SCPI Command Reference 
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