Rockwell Automation 61C544A RTD Module - Manual (Page 22)

4Ć6
4.1.5 Low Low Alarm Status Register (Register 19)
Register 19 indicates the current status of each configured channel's
Low Low alarm. See figure 4.5. A bit is set in this register whenever a
channel's input value is less than the configuredLow Low alarm limit.
The bit is reset when the input value returns to a level above the
configuredlimit.
Register 19
Bits 0Ć15
Bit 0ă=ăChannel 0 Bit 5ă=ăChannel 5 Bit 10ă=ăChannel 10
Bit 1ă=ăChannel 1 Bit 6ă=ăChannel 6 Bit 11ă=ăChannel 11
Bit 2ă=ăChannel 2 Bit 7ă=ăChannel 7 Bit 12ă=ăChannel 12
Bit 3ă=ăChannel 3 Bit 8ă=ăChannel 8 Bit 13ă=ăChannel 13
Bit 4ă=ăChannel 4 Bit 9ă=ăChannel 9 Bit 14ă=ăChannel 14
Bit 15ă=ăChannel 15
R R R R R R R R R R R R R R R R
15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
Figure 4.5 Ć Low Low Alarm Status Register
4.1.6 Out of Range Status Register (Register 20)
Register 20 indicates the current status of each configured channel's
Out of Range alarm. See figure 4.6. A bit is set in this register
whenever a channel's A/D input value exceeds the physical
limitations of the A/D converter. These limits are -200 o C to 500 o C.
The bits in this register are not latchedautomatically. If you want a bit
to be latchedthe first time a value goes out of range, you must latch
it through the application program.
If an input is identified as being out of range, the most probable
cause is that a wire between the module and the RTD has either not
been connectedor has been broken.
Register 20
Bits 0Ć15
Bit 0ă=ăChannel 0 Bit 5ă=ăChannel 5 Bit 10ă=ăChannel 10
Bit 1ă=ăChannel 1 Bit 6ă=ăChannel 6 Bit 11ă=ăChannel 11
Bit 2ă=ăChannel 2 Bit 7ă=ăChannel 7 Bit 12ă=ăChannel 12
Bit 3ă=ăChannel 3 Bit 8ă=ăChannel 8 Bit 13ă=ăChannel 13
Bit 4ă=ăChannel 4 Bit 9ă=ăChannel 9 Bit 14ă=ăChannel 14
Bit 15ă=ăChannel 15
R R R R R R R R R R R R R R R R
15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
Figure 4.6 Ć Out of Range Status Register