Recovering From Communication Halts; The Xmp's Input And Output Queues; Communicate With The Xmp 2600; Using Queries - Xantrex XMP 2600 Programming Manual

Xantrex multiple output power system
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How to communicate with the XMP 2600
To use this synchronization feature properly, you must follow each message sent to the
XMP 2600 with a read operation, reading one character and verifying its value (6).

Recovering from communication halts

If, for some reason, communication with the XMP 2600 halts, use one of the following
methods to clear the XMP's input and output queues and reestablish communication:
The XMP's
The XMP 2600 uses two queues (256 bytes long, each) for holding input (data you send
to the XMP) and output (replies you should read from the XMP).
input and
output
You must make sure not to fill those queues up or communication with the XMP 2600
may, in some situations, fail.
queues
Communicate
The following paragraphs elaborate on the proper usage of commands and queries while
communicating with the XMP 2600.
with the XMP
2600

Using queries

When using queries (questions) with the XMP 2600, you must make sure that for each
query that you send to the XMP 2600, you read the reply the XMP 2600 has placed in its
output queue.
Although it is possible to send several queries and then read all the replies (you will need
a separate read for each reply), it is a better practice to send a single query and read its
reply before sending another query.
If for some reason you find out that the reply you are reading is not for the query you
have sent (lost of synchronization between replies and queries) send the BUFCLR
command or use one of the procedures depicted above at "recovering from
communication halts". This operation will clear both the input and the output queues of
the XMP 2600 and resynchronize queries with replies.

Using commands

The XMP 2600 stores the commands (and queries) that you send to it in its input queue
until it is ready to parse and execute them.
Parsing and executing the commands and queries is done when the XMP 2600 is not busy
communicating with its Power Modules.
This means that command execution might be held of for as long as a second (usually
commands are executed within 200mS).
If you send many commands with short intervals between them, sometimes you may get
into a situation where the XMP's input queue will fill up due to commands waiting for
execution. This might lead to a communication halt.

Programming the XMP 2600

Bearing in mind all of the above, you should follow the guidelines in the following
paragraphs:
6
1. Press the front panel LOCAL button.
2. Send a GPIB bus DCL (Device Clear) multi-line command.
3. Reset the XMP 2600 using the front panel buttons DEL & LOCAL.
4. Reset the XMP 2600 using the hardware command (on/off) connector at its rear.
5. Reset the XMP 2600 by cycling its power.
XMP 2600 Programming Manual
Usage Guidelines
rev. 1.1

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