Clearing the Status Byte (STB) Register

[Raj 604]

As per the 488.2 spec, it seems that ClearDevice followed by Send "*CLS"
should clear the status byte (STB) register. Am I right?
I was working with some SCPI compliant devices where in this did not happen always.
Is this a problem with the devices or is my understanding of the 488.2 spec incorrect?

Any help is appreciated.

Thanks,
Raj

[Ryan_M]

The *CLS command was added as a mandatory command to the 488.2 standard as a means to clear the status. The DeviceClear function sends the SDC message to the addressed listener. How the device reacts to these functions might be best documented by the vendor.

[Raj 604]

Thanks for the reply Ryan.
As you have said, *CLS should clear all the status data structures and hence all the status summary bits should also be cleared. This would mean that all STB bits except MAV would be cleared. ClearDevice would clear the output queue and hence the MAV bit.

Thus for a 488.2 compliant device, ClearDevice followed by *CLS should clear all bits in the STB. Of course, individual instruments can differ in behavior.

Do you agree with me Ryan.

Thanks