Set address problems, Setting number of polled addresses – National Instruments NI-FBUS User Manual
Page 118
Appendix B
Troubleshooting and Common Questions
© National Instruments Corporation
B-9
NI-FBUS Configurator User Manual
If a device does not publish the data you configured it to transmit, complete
the following steps:
1.
Edit the schedule to add more time to the communication schedule.
To edit the schedule, double-click the Schedule icon in the
configuration tree.
For more information about editing the schedule, refer to the
section of Chapter 2,
2.
If your project reads and polls information continuously, turn off
polling to see if the device publishes the data. To turn off polling,
uncheck the Periodic Updates checkbox at the top of the block
configuration window.
Set Address Problems
A device does not accept a permanent address.
The device does not have a tag. For instructions on setting the tag, refer
to the
section of Chapter 2,
. If the device already has a tag, the T3 network parameter
might not be the right length. Remove the device from the active bus and
configure its address separately.
Why are my MIB parameters all showing up as zero?
If you have no address assigned, the NI-FBUS Configurator is not able to
read the parameters.
I get a Read vfdlist fail error.
There are probably two devices at the same address. Change one to a
different address.
Setting Number of Polled Addresses
The Fieldbus specification describes how a Link Active Scheduler (LAS)
device probes a list of addresses to allow devices to come online during
normal operation. The LAS sends a Probe Node (PN on the bus monitor)
packet to each address in its list of addresses every so often during
operation, where “every so often” is a time that depends on the number of
devices on the link, and the setting of the Link Maintenance Token Hold
Time parameter.