EXFO FLS-2200, User Manual

Page: 46 / 185

Using Your Broadband Source in an Automated Test Environment
Broadband Source
37
Message Management
Output queue

Consists of a First-In, First-Out
(FIFO) data structure.

When the instrument acts as a
talker, it sends response messages
(from the output queue) to the
controller. Response messages all
end with a <
RESPONSE MESSAGE
TERMINATOR>
, see the appendix
on data types.

Total storage capacity: only limited
to the device’s memory.

As soon as there is data in the
output queue, the Message
AVailable bit (bit number 4 –MAV
from the Status Byte register) is set
to 1.

Remains empty if no query is
received or if the query contains
an error.
The Output queue will be
cleared by:

Reading all the items it
contains.

Turning off the power.

Sending a Device Clear
(DCL) message to the
instrument.

Sending a
Selected Device Clear
(SDC) message to the
instrument.

Attempting to send a
command before
reading the responses to
previous queries (an
error will also be
raised).
Data structure Characteristics Clearing