Honeywell Touchpoint Pro Technical Handbook page 151

Category
mA input channel
mA input channel
mA Input channel
Modbus
Modbus
Modbus
Module
configuration
Part. No. 2400M2501_6
TROUBLESHOOTING
Fault / Problem Possible Cause
Inhibit Delay is
active
Sensor /
Transmitter is
signalling Inhibit
There is a The mA loop
discrepancy requires
between the calibration
sensor reading
and the value
displayed by
Touchpoint Pro
Error 'Calibration
The parameter
'Maximum Span
Signal Too High'
occurs when Signal' has been
calibrating the mA exceeded (default
loop value 20 mA)
Fluctuating input HART
signal communication
with the
corresponding
field device
No Modbus
Communication
Communication
data errors
No response from
Touchpoint Pro
Module is still Module has not
showing as been properly
present and removed from the
available for system
configuration in
the System Setup
Remedial Action
Wait for the Inhibit Delay time to elapse. (If the Power-
On Delay or Fault Recovery Delay is enabled, the
system will remain in Inhibit for a period defined by the
Inhibit Delay Time.) Please refer to Ch. 9.3.13 Inhibit
Delay Settings
The Sensor / Transmitter may be in a start-up
sequence, or may have been inhibited for maintenance.
Refer to the Input Details for that channel from the
Inputs screen.
Touchpoint Pro converts the 4-20 mA signal it receives
from the sensor to a gas reading. If the discrepancy is
significant,
re-calibrate the 4-20 mA loop by forcing the sensor
output to 4 mA then 20 mA, see Commissioning,
Calibrating a mA input channel
Review the configuration of the channel. Under
Calibration Settings, verify the value Maximum Span
Signal. If necessary, use a lower forced mA value to
calibrate the channel. Verify that the transmitter is
operating correctly.
HART communication with the field device may appear
as a fluctuation on the incoming signal. This will clear
when HART communication ceases.
Verify that the system has a Bus Interface Board (BIB)
fitted. Check the wiring between the Control Module
terminal blocks TB6 and TB7 and the host computer
system port. Try swapping over TDA and TDB.
Check that the serial communication configuration
parameters of the host computer system and
Touchpoint Pro are the same.
Ensure that the bus is correctly terminated. If this is the
case remove the bus terminators and retry
communication.
Consider adding network bias resistors. Please refer to
Ch. 11 Configuring Modbus for further details.
Check the data signal wiring is not routed near sources
of electrical noise. Check for earth loops. Ensure that
the bus is correctly terminated. If this is the case remove
the bus terminators and retry communication.
Consider adding network bias resistors.
If possible use an oscilloscope to examine the signals
on the highway and take appropriate corrective action.
Check the address parameter used in requests issued
by the host computer system matches the address
allocated to the slave node. In multi-drop systems check
that all nodes have a unique address.
Follow the instructions to remove a module from the
system, see Maintenance, How to Remove or
Decommission an I/O Module
144
Touchpoint Pro
Technical Handbook