PDL5 User Manual
PDL5-UM-00001 Rev 001
50
Bit 7 (power on) is set when an off-to-on transition occurs in the power
supply of the meter.
Standard Event Status Enable Register
The contents of the standard event status enable register determine which
events in the standard event status register are reflected in the event summary
bit (ESB) of the status byte register.
Queues
Input Queue
The input queue in the meter is a first-in-first-out (FIFO) queue and is 128
characters in length. Data bytes received from the controller are placed in the
input queue in the order received. When a full message meter is received, it is
transferred to the parser.
If the input queue becomes full while the GPIB is being used, the data
acknowledge signal (DAQ) is not sent to the GPIB controller until a character is
transferred from the input buffer to the parser. This ensures that no bytes in the
program message are lost. However, the RS232C interface has no DAQ signal
and cannot be signaled when the input queue becomes full. Therefore,
characters sent to the PDL5 Meter are lost.
If a new program message is received before the response to a query in a
previous message is read, the output queue is cleared, MAV is set to false, and
the query error bit is set. This error is also referred to as an unterminated error.
Output Queue
Responses to query messages are placed in the output queue. This queue is 128
characters in length. When a response is placed in the output queue, the MAV
bit in the status register is set. The MAV bit is cleared when the response is sent.
Standard Event Status Enable Register
Read with
*ESE?
common query
Written to with
*ESE
common command
Cleared by
Power-on
*ESE
common command with a parameter 0