Honeywell ST700 - 6.2 Troubleshooting the transmitter

Revision 2.0 FOUNDATION Fieldbus ST 700 Pressure Transmitter User's Guide Page 95
6.2 Troubleshooting the transmitter
Device not visible on the network
If a device cannot be seen on the fieldbus network, the device may not be powered up or
possibly the supervisory or control program is not able to find (or polling) the node address
of that device. See the following table for possible causes and recommended actions.
Symptoms
Device not visible on the network
Possible cause Things to check Recommended action
Device may have a node
address that is within the
“unpolled range” of addresses.
Verify the following settings:
• First Unpolled Node
• Number of Unpolled Nodes
Set Number of Unpolled
Nodes to “0”.
No power to the device. Measure the DC voltage at the
device’s SIGNAL terminals.
Voltage must be within the limits.
If no voltage or voltage is out
of operating limits, determine
the cause and correct it.
Insufficient current to the
device.
Measure the DC current to the
device. The DC current must be
within the limits.
If the current is insufficient,
determine the cause and
correct it.
More than two or less than two
terminators are wired to
fieldbus link.
Check to see that only two
terminators are present on a link.
Correct, if necessary.
Insufficient signal to the
device.
Measure the peak-to-peak signal
amplitude. The output must be
0.75 to 1.0 Vp-p.
Measure the signal on the + and -
SIGNAL terminals and at a
frequency of 31.25k Hz.
If the signal amplitude is
insufficient, determine the
cause and correct it.
Names of parameters are not
visible.
Missing or incorrect version of
Device Description file on host
computer.
Check the path to the Device
Description.
Load correct version of DD.