User Manual LW120
with LMPC option.
*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 LW120 functionality is tested.
0 - Selftest passed
1 - CPU to peripherals communication failure
2 – Channel 1 failure
4 – Channel 2 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 LW120 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
register are logically ORed together to form a single summary bit. The
Remote Programming Reference 4-61
