Chapter 4 Command Reference

*ESR?

(Event Status Register Query)

*ESR?

(Event Status Register Query)

*ESR?

Queries the Standard Event Status Register, shown in Figure 4-5.

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.” That is,

they cannot be cleared even if they do not reflect the current status of a related condition, until they are read.

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 4-5. Standard Event Status Register

See the section titled “Standard Event Status Register Group,”

page 3-24, in Chapter 3 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 unused bit is zero.

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Programming Guide