Agilent Technologies 34401A manual Bit Definitions Status Byte Register

Chapter 4 Remote Interface Reference

The SCPI Status Model

The Status Byte

The status byte summary register reports conditions from other status registers. Query data that is waiting in the multimeter’s output buffer is immediately reported through the “message available” bit (bit 4). Bits in the summary registers are not latched. Clearing an event register will clear the corresponding bits in the status byte summary register. Reading all messages in the output buffer, including any pending queries, will clear the message available bit.

Bit Definitions – Status Byte Register

	Bit	Decimal	Definition
		Value
0	Not Used	1	Always set to 0.
1	Not Used	2	Always set to 0.
2	Not Used	4	Always set to 0.
3	Questionable Data	8	One or more bits are set in the Questionable Data
			register (bits must be “enabled” in enable register).
4	Message Available	16	Data is available in the multimeter’s output buffer.
5	Standard Event	32	One or more bits are set in the Standard Event
			register (bits must be “enabled” in enable register).
6	Request Service	64	The multimeter is requesting service (serial poll).
7	Not Used	128	Always set to 0.

The status byte summary register is cleared when:

•You execute a *CLS (clear status) command.

•Querying the standard event and questionable data registers will clear only the respective bits in the summary register.

The status byte enable register (request service) is cleared when:

•You turn on the power and you have previously configured the multimeter using the *PSC 1 command.

•You execute a *SRE 0 command.

The status byte enable register will not be cleared at power-on if you have previously configured the multimeter using *PSC 0.

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