Spectrum Controls 1769sc-HART Modules - Manual (Page 65)

Chapter 4: Module Data, Status, and Configuration
User's Manual 0300215-03 Rev. A
6-15
Section 6.5
Output Data File
The output data file allows you to control module features such as, clearing process
alarms, suspending HART acquisition, and allows managing of HART messages to and
from HART field devices. The data table structure is shown in the table below.
Table 6-9 (Output Data File)
Word/Bit 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
0 HS3 HS2 HS1 HS0 UL3 UH3 UL2 UH2 UL1 UH1 UL0 UH0
1
2
3
4..23
24..45 Reserved
Reserved
Message Request Buffer
Packet Just Scanned
Message Master Control
Message Request Size
6.5.1 Unlatch Process High Alarms UH0 to UH3 (Word 0)
UH0 through UH3 will unlatch the high process alarms for channels 0 through 3
respectively. Refer to section Filter Frequency and General Settings (Words 2, 8, 14, 20)
for more information regarding setting the alarm latch function. To unlatch the high
process alarm on a given channel, set the unlatch bit to 1.
Note: Setting the unlatch process alarm bit will not clear the alarm latch if the
conditions that generated the alarm are still present.
Note: It is up to the user to keep the unlatch bit set until verification that the process
alarm bit has cleared. When the process alarm bit has cleared the user can then clear
the unlatch process alarm bit.
Note: The module will not latch the high process alarm if a transition from “no alarm
condition” to “alarm condition” occurs while the unlatch high process alarm bit is set.
6.5.2 Unlatch Process Low Alarms UL0 to UL3 (Word 0)
UL0 through UL3 will unlatch the low process alarms for channels 0 through 3
respectively. Refer to section Filter Frequency and General Settings (Words 2, 8, 14, 20)
for more information regarding setting the alarm latch function. To unlatch the low
process alarm on a given channel, set the associated unlatch alarm bit to 1.
Note: Setting the unlatch process alarm bit will not clear the alarm latch if the
conditions that generated the alarm are still present.
Note: It is up to the user to keep the unlatch bit set until verification that the process
alarm bit has cleared. When the process alarm bit has cleared the user can then clear
the unlatch process alarm bit.
Note: The module will not latch the low process alarm if a transition from “no alarm
condition” to “alarm condition” occurs while the unlatch low process alarm bit is set.
6.5.3 Hart Suspend HS0 to HS3 (Word 0)
HS0 to HS3 are used to suspend all HART acquisition, except Pass-through messages, on
channels 0 through 3 respectively. To suspend HART acquisition, set the associated
channel suspend bit to 1. Normal HART acquisition will resume when the bit is cleared.
6.5.4 Packet Just Scanned (Word 1)
When demultiplexing HART data from the module, this output word can be used to
speed up the acquisition process by overriding the automatic 500ms acquisition delay