Specifications

Analog Input Modules
66
31007715 6/2008
Input Status
Registers
The second and fourth STB AVI 1270 registers in the input block of the process
image are the status registers for the two analog input channels. The six LSBs in
each register represent the status of each input channel:
1 Bit 0 is the global status (GS) bit for the input channel. It has a value of 0 when no errors
have been detected. It has a value of 1 when bit 1, bit 3, and/or bit 5 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 if sensor power is absent. A
PDM error turns on the GS bit (bit 0).
3 Bit 2 represents the presence or absence of an OVW. It has a value of 0 when the voltage
is less than or equal to 10 V. It has a value of 1 when the voltage is greater than 10 V. An
OVW in the STB AVI 1270 does not turn on the GS bit (bit 0).
4 Bit 3 represents the presence or absence of an OVE. It has a value of 0 when the voltage
is less than 10.24 V and a value of 1 when the voltage equals or exceeds 10.24 V. An OVE
in the STB AVI 1270 turns on the GS bit (bit 0).
5 Bit 4 represents the presence or absence of a UVW. It has a value of 0 when the voltage
is greater than or equal to -10 V and a value of 1 when the voltage is below -10 V. A UVW
in the STB AVI 1270 does not turn on the GS bit (bit 0).
6 Bit 5 represents the presence or absence of a UVE. It has a value of 0 when the voltage
is greater than -10.24 V) and a value of 1 when the voltage is less than or equal to -
10.24 V). A UVE in the STB AVI 1270 turns on the GS bit (bit 0).
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 AVI 1270 Status Register Format
always set to 0
67
1
23
45
0
1415
9
10
111213
8
not used;
GS (see 1)
PDM (see 2)
OVW (see 3)
OVE (see 4)
UVW (see 5)
UVE (see 6)
Artisan Technology Group - Quality Instrumentation ... Guaranteed | (888) 88-SOURCE | www.artisantg.com