Technical/Programming Manual
FT1020G3 Rev 2.2.1
95
(ISO no. 1 / sequence no. 1) will be re-enabled, if this is possible, and so on. The
isolator just before a short circuit cannot be re-enabled.
The Control Unit algorithm will now try to re-enable the first isolator in the B-
direction (ISO no. 3 / sequence no. 3 in Figure 33). If this is possible, the next
isolator in the B-direction, and so on.
Finally all isolators will be re-enabled except the isolator on each side of a short
circuit and any isolator(s) between two or more breaks on the loop.
Communication will be in both directions for 10 minutes. Then a new “cycle” starts.
If the “fault(s)” are not corrected, the communication will be in both directions for
another 10 minutes when a new “cycle” starts, and so on.
If the “fault(s)” are corrected, the communication will return to be in the A-direction
only.
Depending on if it is too low voltage on the loop, short circuit, one break or two or more
breaks, the fault messages will be different.
FAULT: Cut-off loop x, Control Unit xx
SCI nn <-> SCI nn
NOTE: nn = A, 00, 01, 02, 03, 04, 05 - - up to 63 or B.
FAULT: Short circuit loop x, Control Unit xx
SCI nn <-> SCI nn
NOTE: nn = A, 00, 01, 02, 03, 04, 05 - - up to 63or B.
If there are multiple loop faults, i.e. one or more short circuits and/or one or more Cut-offs,
there will be a “multiple COM loop fault” message.
FAULT: Multiple faults, COM loop x,
Control Unit xx
The first fault message will show the first fault in the A-direction.
There will always be a “no reply” message for all units not found in spite of communication
in both directions.
FAULT: No reply zone: xxx address xx
Technical number xxxxxx
Alarm text for xxx-xx
Regarding Fault acknowledge, see the FT1020G3 Operation Manual.
Note:
After the faults are acknowledged it can take up to 10 minutes before the faults can
disappear from the fault list, since the check ("cycle") starts every 10th minute.
