Chapter 4 Command Reference

*STB?

(Status Byte Query)

*STB?

(Status Byte Query)

*STB?

Queries the Status Byte Register, shown in Figure 4-7.

This register is cleared at power-on.

This query does not directly alter the Status Byte Register (including the

MSS/RQS bit) or anything related to the generation of SRQ.

Figure 4-7. The Status Byte Register

See the section titled “Status Byte Register and Service Request Enable Register,” page 3-21, in Chapter 3 of this guide for a detailed description of the Status Byte Register.

Query Response ∙ Numeric data transferred as ASCII bytes in <NR1> format.

Range is 0 to 255.

The response value when rounded to an integer value and expressed in base 2 (binary), represents the bit values of the Status Byte Register.

The value of unused bits is zero when queried.

The Master Summary Status, not the RQS message, is reported on bit 6. Master Summary Status indicates that the Counter has at least one reason for requesting service. (The Master Summary Status is not sent in response to a serial poll; the IEEE 488.1 RQS message is sent instead.) It is the inclusive OR of the bitwise combination (excluding bit 6) of the Status Byte Register and the Service Request Enable Register.

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HP 132A, 53131A manual Status Byte Query, Stb?