Rockwell Automation 1769-OF2 Compact I/O Analog Modules - Manual (Page 100)

Publication 1769-UM002B-EN-P - July 2005
4-18 Module Data, Status, and Channel Configuration for the Output Modules
1769-OF8C and -OF8V
Output Data File The structure of the output data file is shown in the table below. Words 0
through 7 contain the commanded analog output data for channels 0 through
7, respectively. The most significant bit is the sign bit. Word 8 contains the
control bits for unlatching alarms.
Channel Alarm Unlatch
These bits are written during run mode to clear any latched low- and
high-clamps and under- and over-range alarms. The alarm is unlatched when
the unlatch bit is set (1) and the alarm condition no longer exists. If the alarm
condition persists, then the unlatch bit has no effect. You need to keep the
unlatch bit set until verification from the appropriate input channel status
word says that the alarm status bit has cleared (0). Then you need to reset (0)
the unlatch bit. The module will not latch an alarm condition when a transition
from a no alarm condition to an alarm condition occurs while a channel’s clear
latch bit is set.
Table 4.7 1769-OF8C and -OF8V Output Data Table
Wo
rd
Bit Position
15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
0 SGN Analog Output Data Channel 0
1 SGN Analog Output Data Channel 1
2 SGN Analog Output Data Channel 2
3 SGN Analog Output Data Channel 3
4 SGN Analog Output Data Channel 4
5 SGN Analog Output Data Channel 5
6 SGN Analog Output Data Channel 6
7 SGN Analog Output Data Channel 7
8 UU7 UO7 UU6 UO6 UU5 UO5 UU4 UO4 UU3 UO3 UU2 UO2 UU1 UO1 UU0 UO0
Table 4.8 Channel Alarm Unlatch
Wo
rd
Bit Position
15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
0 UU7 (1)
UO7
(2) UU6 UO6 UU5 UO5 UU4 UO4 UU3 UO3 UU2 UO2 UU1 UO1 UU0 UO0
(1) Unlatch channel x under-range or low-clamp exceeded alarm.
(2) Unlatch channel x over-range or high-clamp exceeded alarm.