Flowserve 3400IQ Digital Positioner - Manual (Page 102)

Logix 3400IQ Digital Positioner FCD LGENIM3402-00 – 0/07
02
CAUTION: Additional diagnostics may be available through supervisory and control
applications that monitor and control fieldbus networks. These diagnostics and messages
are dependent upon the capabilities of the application and control system used.
Troubleshooting with the NI-FBUS Configuration Tool
The diagnostic messages generated by the Logix 3400IQ digital positioner and block parameters can
be accessed and evaluated using the NI-FBUS Configurator. Troubleshooting of some Logix 3400IQ
digital positioner faults and corrective actions also can be performed using the configurator.
Fault Summary
Diagnostic messages can be grouped into one of these three categories.
1. Non-critical Failures — Logix 3400IQ digital positioner continues to calculate PV output.
2. Critical Failures — Logix 3400IQ digital positioner drives PV output to fail-safe state.
3. Configuration Errors — Incorrect parameter values may cause the Logix 3400IQ digital
positioner to generate a fault.
A description of each condition in each category is given in the following tables. The condition is
described, a probable cause is stated and a recommended corrective action is given for each fault.
10.3 Device Troubleshooting
Device Not Visible on Network
If the device is not seen on the fieldbus network, the device may not be powered up or possibly the
supervisory or control program is not looking for (or polling) the node address of that device. (See
Table 10.1 for possible causes and recommended actions.)
Table 10.1 Device Troubleshooting A
Symptom
• Device not visible on network
Possible Cause Items to Check Recommended Action
Device may have a node address
that is within the unpolled range of
addresses.
Look at the following settings of
the host system:
• 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 as shown
in Table 4.2 on page 15.
If no voltage or voltage is out of
operating limits, determine cause
and correct.
Insufficient current to device Measure DC current to device. It
should be between 23 and 27 mA.
If current is insufficient, determine
cause and correct.
More than two or less than two
terminators wired to fieldbus link
Check to see that only two termina-
tors are present on link.
Correct, if necessary.
Insufficient signal to device Measure the peak-to-peak signal
amplitude; it should be:
• Output 0.75 to 1.0 Vp-p.
• Input 0.15 to 1.0 Vp-p.
Measure the signal on the + and
- SIGNAL terminals and at a
frequency of 31.25k Hz.
If signal amplitude is insufficient,
determine the cause and correct.
Note: AG-181 can be a valuable tool in troubleshooting network problems.