beautypg.com

Fluke 5020A User Manual

Page 115

background image

Digital Communications Interface

Commands

6

6-45

*ESR?

This query command returns the Event Status Register. It also clears the Event Status

Register and the ESB bit of the Status Byte Register. The value returned indicates the

condition of each of the eight bits of the register by adding the binary-weighted values of

each bit. The meaning of each bit, when set (1) , is as follows where 0 is the least

significant and 7 is the most significant:

0

Operation complete (OPC). Execution of the
last command is completed.

1

Request control (RQC). No function for this
instrument.

2

Query error (QYE). An attempt has been
made to read data when none is available or
pending.

3

Device dependent error (DDE). A hardware
error condition occurred.

4

Execution error (EXE). An invalid parameter
for a command has been received or the
command could not be executed under
existing conditions.

5

Command error (CME). An unrecognized
command or a command with improper syntax
has been received.

6

User request (URQ). No function for this
instrument.

7

Power on (PON). Always set after the power
is switched on.

The ESB bit of the Status Byte Register (Section ) is set (1) whenever any bit of the

Event Status Register is set and its corresponding mask bit in the Event Status Enable

Register (Section ) is set. The Event Status Register is cleared when queried with the

ESR? command or when the *CLS command is received. The response in the following

example would be given after an invalid command is received by the 1560 and no other

error occurred.
Example command: *ESR?
Example response: 32

*SRE?

Returns the Service Request Enable Register. (See *SRE command below.)
Example: *SRE?
Response: 0

*SRE |MIN|MAX|DEF

This command sets the Service Request Enable Register. This register determines which

event bits of the Status Byte Register affect the MSS Master Summary Status message bit

of the Status Byte Register and generate a service request with the IEEE-488 interface. If

any event bit of the Status Byte Register is set (1) while its corresponding mask bit of the

Service Request Enable Register is set, the MSS Master Summary Status message bit of

the Status Byte Register will be set and a service request generated. The value of the

parameter is a number from 0 to 255 that is the sum of the binary-

weighted values of each mask bit. The Status Byte Register is described in section

5.5.10.9 below. The following example causes the MSS bit in the Status Byte Register to

be set and a service request to be generated whenever the ESB bit of the Status Byte

Register is set.