HP 53150A Series, Programming Manual

Page: 149 / 186

Chapter 4 Command Reference
Common Commands
Programming Guide 4-49
4
*ESR?
(Event Status Register Query)
COMMAND
*ESR?
Queries the Standard Event Status Register, shown in Figure 4-4.
This event register captures changes in conditions, by having each event
bit correspond to a specific condition in the instrument. An event becomes
TRUE when the associated condition makes the defined transition. The
event bits, once set, are “sticky”—i.e., they cannot be cleared until they are
read, even if they do not reflect the current status of a related condition.
This register is cleared by *CLS, by *ESR?, and at power-on. Note that the
instrument's power-on sequence initially clears the register, but then
records any subsequent events during the power-on sequence including
setting the PON (power on) bit.
Figure 4-4. Standard Event Status Register
See the section titled “Standard Event Status Register” on page 3-30 of
this guide for a detailed description of the Standard Event Status
Register.
QUERY RESPONSE
• Numeric data transferred as ASCII bytes in <NR1> format.
• Range is 0 to 255.
• The query response is an integer formed by the binary-weighting of
the bits. The value of any unused bit is zero.
(1)
Operation Complete
Not Used
(4)
Query Error 2
(8)
Device Dependent Error 3
(16)
Execution Error
4
(32)
Command Error
5
Not Used 6
(128)
Power On 7
Bits
0
1