Fluke 2625A, 2620A user manual Reading the Status Byte Register

2620A, 2625A

Users Manual

Bit

0

1

2

Name

OPC

not used

QYE

Table 4-5. Event Status Register

Description

Operation Complete. Set true (1) upon execution of the *OPC command, indicating that the instrument has completed all selected pending operations.

Always set to 0.

Query Error. Generated true (1) by the INTERRUPTED or UNTERMINATED message exchange state transitions. (See IEEE-488.2.) Sets the QYE bit of the Event Status Register. Under RS-232, this causes the "?>" prompt to be returned.

3

4

DDE

EXE

Device Dependent Error. Generated true (1) by overflows of the RS-232 input buffer or by calibration errors. Sets the DDE bit of the Event Status Register. Under RS-232, this causes the "!>" prompt to be returned.

Execution Error. Generated true (1) by parameters out of bounds or by a valid command that could not be processed due to an internal condition (such as calibration commands being received when calibration is not enabled). Sets the EXE bit of the Event Status Register. Under RS-232, this causes the "!>" prompt to be returned.

5

6

7

CME

not used

PON

Generated true (1) by syntax errors, including: unrecognized command, incorrect command sequences, and GET messages inside a <program message>. Sets the CME bit of the Event Status Register. Under RS-232, this causes the "?>" prompt to be returned.

Always set to 0.

Always set to 0 Power On. Set true (1) after an off-to-on transition has occurred in the instrument’s power supply.

Reading the Status Byte Register

The host can read the Status Byte Register by taking a serial poll or by sending the instrument a *STB? query. The value of the status byte is not affected by the *STB? query.

Note

Changes to the status or enable registers are evaluated immediately. Therefore, an adequate change in cause or enabling criteria will change the status byte.

When the Status Byte Register is read, an integer is returned. This integer is the decimal equivalent of an 8-bit binary number. For example, 48 is the decimal equivalent of the binary 00110000, meaning that bit 4 (MAV) and bit 5 (ESB) are set to "1". Bit 4 contributes integer 16, and bit 5 contributes integer 32.

If the status byte is read by serial poll, bit 6 is returned as a request service (RQS); if it is read with an *STB? query, bit 6 is returned as Master Summary Status (MSS).

EXAMPLE EXPLANATION

*STB?	Reads the Status Byte Register. Assume that "32" is returned. Converting 32
	to the binary 00100000 indicates that bit 5 (ESB) is set to 1. To determine
	the event status, you would have to read the Event Status Register in the
	same manner, using the *ESR? query.

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