User Guide

Fault tracing Honeywell • 35
7.3 Other fault conditions
The following fault tracing diagram will help you to locate and fix some of the most usual prob-
lems. If the problem persists contact your local distributor.
Figure 9. Fault tracing diagram for Modbus RTU
Drive does not start from the bus
Check communi- cation status (par. 5.7.3.2.1/5.8.3.2.2) Counter does not run Counter for bad frames (see Table 3) increases Counter OK.
No communication Poor communication
Is the device in READY state? Check the led on keypad Check external interlockings (I/O)
Is fieldbus selected as control place? Check parameter M1.15 or M3.2.1
Does Master give RUN command? Use keypad to monitor variable M5.7.3.2.5 Set variable AV36 to ‘1’
Check fieldbus parameters Check other field- bus parameters in menu M5.8 Check selected protocol (M5.7.1.1)
Check Master’s parameters Check configura- tions (Slave add- ress, baudrate etc.)
Check termination resistors Check that both ends of the fieldbus line have termina- tion resistors (chapter 4.2)
Check cabling Check cable for cuts Check correct place- ment of conductors in terminals
Other bus devices Check other necessary devices (e.g. router)
Check termination resistors Check that both ends of the fieldbus line have termi- nation resistors (chapter 4.2) Check parameters
Check cabling Check distances between cables, see chapter 4.2. Check cable types, see chapter 3.
Check grounding Check grounding, see chapter 4. Re- member to make grounding for each device!
Check connections Check stripping of cables and conductors, see chapter 4. Check terminals for loose connections