ADLINK aTCA-9300 - Manual (Page 34)

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4.1.5 Get Sensor Reading Command
Byte Data field
Request data 1 Sensor Number (FFh = reserved)
1 Completion Code
2 Sensor reading
Byte 1: byte of reading. Ignore on read if sensor does not return an
numeric (analog) reading.
3 [7] - 0b = All Event Messages disabled from this sensor
[6] - 0b = sensor scanning disabled
[5] - 1b = reading/state unavailable (formerly “initial update in progress”).
This bit is set to indicate that a ‘re-arm’ or ‘Set Event Receiver’ command
has been used to request an update of the sensor status, and that update
has not occurred yet. Software should
use this bit to avoid getting an incorrect status while the first sensor
update is in progress. This bit is only required if it is possible for the
controller to receive and process a ‘Get Sensor Reading’ or ‘Get Sensor
Event Status’ command for the sensor before the update has completed.
This is most likely to be the case for sensors, such as fan RPM sensors,
that may require seconds to accumulate the first reading after a re-arm.
The bit is also used to indicate when a reading/state is unavailable
because the management controller cannot obtain a valid reading or state
for the monitored entity, typically because the entity is not present. For
more in formation, please see Section 16.4, Event Status, Even
Conditions, and Present State
and Section 16.6, Re-arming on the
PICMG specification 3.0.
[4:0] - reserved. Ignore on read.
4 For threshold-based sensors
Present threshold comparison status
[7:6] - reserved. Returned as 1b. Ignore on read.
[5] - 1b = at or above (≥) upper non-recoverable threshold
[4] - 1b = at or above (≥) upper critical threshold
[3] - 1b = at or above (≥) upper non-critical threshold
[2] - 1b = at or below (≤) lower non-recoverable threshold
[1] - 1b = at or below (≤) lower critical threshold
[0] - 1b = at or below (≤) lower non-critical threshold
For discrete reading sensors
[7] - 1b = state 7 asserted
[6] - 1b = state 6 asserted
[5] - 1b = state 5 asserted
[4] - 1b = state 4 asserted
[3] - 1b = state 3 asserted
[2] - 1b = state 2 asserted
[1] - 1b = state 1 asserted
[0] - 1b = state 0 asserted
Response data
(5) For discrete reading sensors only. (Optional)
(00h Otherwise)
[7] - reserved. Returned as 1b. Ignore on read.
[6] - 1b = state 14 asserted
[5] - 1b = state 13 asserted
[4] - 1b = state 12 asserted
[3] - 1b = state 11 asserted
[2] - 1b = state 10 asserted
[1] - 1b = state 9 asserted
[0] - 1b = state 8 asserted