Frequently Asked Questions
89
5.
Consider selecting “No Harmonics” synchronization. The maximum bus speed
quoted for the 2553/ 2553E includes the calculation of up to 40 harmonics for all
signals. If these are disabled by using this synchronization selection then a
significant increase in speed can be achieved. The actual increase is very dependent
on many issues. Note that harmonics results and waveforms are not available in this
configuration.
6.
Select either a graphical front panel display, or the blank display for the 2553/
2553E. These displays offer the highest display update rates, which has an impact
on the time available for IEEE488 bus transfers. The slowest displays are the textual
ones, e.g.,
Basics, Harmonic Listing
and
Setup
. The fastest display is the blank
display. This can yield up to 10% improvement.
I’m using the 2553/ 2553E with an IEEE488 Bus Isolator and
getting unreliable data transfers from the 2553/ 2553E to the
controller, what is wrong?
This is a known issue with certain National Instruments Optically Isolated IEEE488 Bus
Isolators. The symptom is that the leading space character, which the 2553/ 2553E
always issues when read, is sometimes missing at the controller. The user should contact
National Instruments regarding upgrading the isolator.
Other isolators and controllers may also have this problem. Many IEEE488 bus
instruments only format a response when addressed to talk, thus there is usually some
delay between the device being addressed to talk, and the device starting to place data
onto the bus. The 2553/ 2553E always has pre-formatted responses available, thus there
is virtually no delay before the 2553/ 2553E is ready to place data onto the bus. During
the manufacturers’ testing of the bus isolator or controller this possibility may not have
been foreseen and may cause problems that appear specific to the 2553/ 2553E.
This can also cause problems with the users’ controller software when configuring for
DMA activity. The user should ensure that the correct DMA channel has been
configured and enabled prior to addressing the 2553/ 2553E to talk.
I have configured the 2553/ 2553E to assert the SRQ line but it
never gets asserted
This is often caused by one or more of the following –
•
The configured reason for the 2553/ 2553E to assert the SRQ line has never
occurred.
•
The driver for the controller has been configured for automatic serial poll. When this
has been configured the driver will immediately serial poll the 2553/ 2553E, causing
it to release the SRQ line.
•
Another application is running on the controller that is performing a serial poll,
releasing the SRQ line.
Summary of Contents for Xitron 2553
Page 1: ...IEEE488 COMMAND GUIDE 2553 2553E Three Phase Power Analyser ...
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Page 10: ...10 2553 2553E Command Guide ...
Page 38: ...38 2553 2553E Command Guide ...