Read/write errors – National Instruments NI-FBUS User Manual
Page 117
Appendix B
Troubleshooting and Common Questions
NI-FBUS Configurator User Manual
B-8
ni.com
Read/Write Errors
The Write Contained Block Parameters option when downloading
causes all contained parameters to be written—not just those that were
changed. This can cause error messages for parameters that you did not
even modify because they are initially set to illegal values as defined in the
Foundation Fieldbus specification. These values are only quasi-illegal.
Devices are often designed to be able to operate with the default illegal
values to allow you to quickly bring up a test system. To encourage you to
set them to values appropriate for your process, trying to write the default
parameter value causes errors. Examples of such parameters are
ALERT_KEY
,
L_TYPE
, and
SHED_OPT
.
You are unable to write to a block parameter.
The parameter is read-only, the blocks are in an incorrect mode, or the data
is out of range. If the parameter is not read-only, complete the following
steps to solve the problem.
1.
Change the target mode to
Man
or
OOS
and then try to write to the
parameter.
2.
The data might be out of range. Check the range and make sure the
value is valid.
A device does not accept a new tag.
The device is in an invalid state. Power the device off and on.
You receive frequent communication errors when you try to read or
write to a device.
•
Other devices are actively and frequently polling the device, causing
reads to time out. Reduce polling. Make sure you disable periodic
updates. If you have scheduled other devices to poll this device
frequently, try changing the poll rate.
•
The device is in an invalid state. Use the
RESET
parameter to cycle
power and reset the device.
A device does not transmit alarms or trends.
Either you have not configured them yet, or there is not enough time on
the schedule. For instructions on how to configure alarms and trends,
refer to the
of Chapter 2,
Using the NI-FBUS Configurator
, respectively.