Specifications

Analog Input Modules
31007715 6/2008 97
Status
Byte Structure
The second, fourth, sixth, and eighth registers in the input block of the process
image are the status words. The STB ACI 0320 can detect and report current
overflow conditions.
The six LSBs in each register represent the status of each input channel:
1 Bit 0 represents global status (GS). It has a value of 0 when no errors have been detected.
It has a value of 1 when bit 1 and/or bit 3 and/or bit 6 and/or bit 7 has a value of 1.
2 Bit 1 represents the status of PDM voltage on the island’s sensor bus. It has a value of 0
when no PDM voltage errors are detected. It has a value of 1 when the isolated field side
voltage is not within range. A PDM error turns on the GS bit (bit 0).
3 Bit 2 represents the presence or absence of an OCW. See current level definitions in the
preceding table. AN OCW does not turn on the GS bit (bit 0).
4 Bit 3 represents the presence or absence of an OCE. See current level definitions in the
preceding table. An OCE turns on the GS bit (bit 0).
5 Bit 4 represents the presence or absence of a UCW. See current level definitions in the
preceding table. A UCW does not turn on the GS bit (bit 0).
6 Bit 5 represents the presence or absence of a UCE. See current level definitions in the
preceding table. A UCE does not turn on the GS bit (bit 0).
7 Bit 6 represents the presence or absence of a BWE. This error is present when the input
channel has a broken wire. A BWE turns on the GS bit (bit 0).
8 Bit 7 represents an internal communications error (ICE). This error will turn on the GS bit
(bit 0).
Note: When the global status bit (GS) is on, the channel data value may not be
valid.
Note: The detection of error conditions on the PDM input power connection may
be delayed by as much as 15 ms from the event, depending on the sensor bus
load, the system configuration and the nature of the fault.
Field power faults that are local to the input module are reported immediately.
STB ACI 0320 Status Register Format
always set to 0
67
1
23
4
5
0
1415
9
10
11
1213
8
not used;
GS (see 1)
PDM (see 2)
OCW (see 3)
OCE (see 4)
UCW (see 5)
UCE (see 6)
BWE (see 7)
ICE (see 8)
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