HP E1429A Presetting the Enable Register and Transition Filter, Service Request Enable Register

The Service Request Enable Register

Presetting the Enable

Register and Transition

Filter

Reading the Status Byte Register

The Status Byte register can be read with either of the following commands:

*STB?

SPOLL

Both commands return the decimal weighted sum of all set bits in the register. The difference between the commands is that *STB? does not clear bit 6 (RQS service request). The serial poll (SPOLL) does clear bit 6. All bits in the Status Byte register with the exception of MAV are cleared with the command:

*CLS

MAV is cleared when data is read from the output queue.

The Service Request Enable register specifies which (status group) summary bit(s) will send a service request message to the computer over HP-IB. The bits are specified (unmasked) with the command:

*SRE <unmask >

All unmasked bits in the Enable register can be determined with the command:

*SRE?

The Service Request Enable register is cleared at power-on, or by specifying an <unmask > value of 0.

The Enable registers and Transition Filters in the Questionable Signal and Operation Status Groups can be preset (initialized) with the command:

STATus:PRESet

All bits in the Enable registers are masked (i.e. <unmask > is 0), and all bits in the Condition registers set corresponding bits in the Event registers on positive (0-to-1) transitions.

Chapter 3 Understanding the HP E1429 Digitizer 173