EsiWelma Sensigas EW40, Инструкция по установке и эксплуатации

Страница: 36 / 96

Type / N.
Rev. Data Page Total pages
EW095.605 5 November 2010
36 96
EsiWelma
s.r.l.
5.3 Possible abnormalities
If the BUS connections of a field device are reversed, the control unit does not recognize
the signal of the field device on the BUS when the configuration key is pressed.
Cabling errors may show up as follows.
PROBLEM POSSIBLE CAUSE REMEDY
The control unit displays an error
message then indefinitely waits to
be restored Reversal of the BUS connections
on the control unit Restore correct connection after
switching off the system
The units considered cannot be
configured Reversal of the BUS connections
on one or more field devices Restore correct connection after
switching off the system
All the LEDs on units concerned
are off Inversion of power supply on
peripheral units Restore correct connection after
switching off the system
Components possibly broken, field
devices off Power supply connections
reversed with BUS connections Replace damaged units
Possible lack of communication
between the control unit and the
field devices Branching on the communication
BUS Restore correct BUS connection
after powering down the system
Possible lack of recognition of field
devices End-of-line jumper circuit open on
the last unit Terminate the end-of-line jumper
circuit on the last unit of the BUS
Lack of difficulty in communication
with the units downstream of it End-of-line jumper circuit
terminated on an intermediate unit
of the BUS Open the end-of-line jumper circuit
on the intermediate unit in question
Probable lack of communication
between the control unit and the
field devices installed further than
1000 m BUS line longer than 1000 m Shorten the BUS length to 1000 m
Table 5.1 – Diagnosis of possible causes of fail
NOTE
Several attempts to set up correct communication are made but when the time-out (that can
also be a few minutes) occurs without the communication being successful, the following
messages are cyclically brought up:
Fig. 5.9 – Error message
E R R O R :
B U S I N C O R R E C T L Y
C O N N E C T E D
W A I T I N G F O R A C T I O N
* W A I T P L E A S E *