Racal Instruments 3162A/B, User Manual

Page: 98 / 144

User Manual 3162A/B
SCPI Command Reference 4-20
Reading the Status
Byte Register
The Status Byte summary register can be read with the *STB? common query.
The *STB? common query causes the generator to send the contents of the
Status Byte register and the MSS (Master Summary Status) summary
message as a single <NR1 Numeric Response Message> element. The
response represents the sum of the binary-weighted values of the Status Byte
Register. The *STB? common query does not alter the status byte.
Clearing the Status
Byte Register
Removing the reasons for service from Auxiliary Status registers can clear the
entire Status Byte register. Sending the *CLS command to the device after a
SCPI command terminator and before a Query clears the Standard Event
Status Register and clears the output queue of any unread messages. With
the output queue empty, the MAV summary message is set to FALSE.
Methods of clearing other auxiliary status registers are discussed in the
following paragraphs.
Service Request
Enable Register
(SRE)
The Service Request enable register is an 8-bit register that enables
corresponding summary messages in the Status Byte Register. Thus, the
application programmer can select reasons for the generator to issue a service
request by altering the contents of the Service Request Enable Register.
The Service Request Enable Register is read with the *SRE? common query.
The response to this query is a number that represents the sum of the binary-
weighted value of the Service Request Enable Register. The value of the
unused bit 6 is always zero.
The Service Request Enable Register is written using the *SRE command
followed by a decimal value representing the bit values of the Register. A bit
value of 1 indicates an enabled condition. Consequently, a bit value of zero
indicates a disabled condition. The Service Request Enable Register is cleared
by sending *SRE0. The generator always ignores the value of bit 6. Summary
of *SRE commands is given in the following.
*SRE0 - Clears all bits in the register.
*SRE1 - Not used.
*SRE2 - Not used.
*SRE4 - Not used.
*SRE8 - Not used.
*SRE16 - Service request on MAV.
*SRE32 - Service request on ESB summary bit.
*SRE128 - Not used.
Standard Event
Status Register
(ESR)
The Standard Event Status Register reports status for special applications. The
8 bits of the ESR have been defined by the IEEE-STD-488.2 as specific
conditions, which can be monitored and reported back to the user upon
request. The Standard Event Status Register is destructively read with the
*ESR? common query. The Standard Event Status Register is cleared with a