TROUBLESHOOTING
OFF-LINE FAILURE
I-E96-322A
6 - 11
Table 6-5. Troubleshooting Off-Line Failures
Problem
Cause
Corrective Action
IMHSS03 fails to cal-
ibrate.
Configuration
error.
Check function code 55 or 150 specifications. Verify that function
code 55 or 150 is set for calibration.
IMHSS03 fails to cal-
ibrate and there are
no configuration
errors.
Improper
installation.
Check the installation of the IMHSS03 and related hardware.
1. Remove the IMHSS03 and check the I/O expander bus
dipshunt. All the dipshunt pins should be shorted.
2. Check the dipswitch settings on the IMHSS03. Refer to Section
3 to verify that the dipswitches are properly set for module installa-
tion.
3. Insert the module in the MMU.
4. Check the termination cable.
a. Verify that the cable is connected to the correct slot on the
MMU backplane.
b. Verify that the cable connects P3 on the IMHSS03 to P1 on
the termination unit or P3 on the termination module.
5. Check the dipshunt settings on the termination unit or the
jumper settings on the termination module. Refer to the
appendices for dipshunt or jumper settings.
6. Check the process wiring. Verify that the process wiring is
connected to the correct terminals on the termination unit or
module. Refer to the appendices for terminal assignments.
7. Check the valve, hydraulic actuator, LVDT and installation of the
servo related hardware.
Contact the manufacturer for information on the servo valve,
hydraulic actuator and LVDT.
IMHSS03 fails to
calibrate and there
are no configuration
or installation errors.
Process
hardware.
Check the process hardware.
LVDT calibration
fails.
LVDT 100%
voltage less
than LVDT 0%
voltage.
Check LVDT connection. Replace LVDT.
Cannot tune
demodulator gain.
Primary oscilla-
tor amplitude.
Adjust amplitude of primary oscillator.
No servo drive from
the servo amplifiers.
Bad connection
to the servo
valve, defective
servo valve.
Check the servo valve.
1. Connect an oscilloscope to the servo valve at the appropriate
termination unit or module terminals (SERVO_C_). Connect the
oscilloscope probes differentially across the + and – terminals of
the servo output. Check the servo outputs by doing Steps 2
through 4. Repeat the procedure for each bad servo output.
2. Enter a position demand to change the actuator position.
3. Verify that there is a servo drive and return signal for each servo
output.
4. If there is no servo valve drive signal or return signal, check the
continuity of the connecting cables.