Modes; Alarm Detection - Emerson Rosemount OCX 8800 Reference Manual

Foundation Fieldbus
Table 7-28:
Condition number
7
8
9
10
11
12
13
14
15
7.9.6

Modes

The PID function block supports the following modes:
•
•
•
•
•
•
•
•
You can configure the Man, Auto, Cas, and O/S modes as permitted modes for operator
entry.
7.9.7

Alarm detection

A block alarm is generated whenever the BLOCK_ERR has an error bit set. The types of
block errors for the AI block are defined above.
Process alarm detection is based on the OUT value. You can configure the alarm limits of
the following standard alarms:
162
BLOCK_ERR conditions
Condition name and description
Input Failure/Process Variable has Bad Status: The parameter linking
to IN is indicating a Bad status.
Output Failure
Memory Failure
Lost Static Data
Lost NV Data
Readback Check Failed
Device Needs Maintenance Now
Power Up
Out of Service: The actual mode is out of service.
Manual (Man): The block output (OUT) may be set manually.
Automatic (Auto): The SP may be set manually, and the block algorithm calculates
OUT.
Cascade (Cas): The SP is calculated in another block and is provided to the PID block
through the CAS_IN connection.
RemoteCascade (RCas): The SP is provided by a host computer that writes to the
RCAS_IN parameter.
RemoteOutput (Rout): The OUT is provided by a host computer that writes to the
ROUT_IN parameter.
Local Override (LO): The track function is active. OUT is set by TRK_VAL. The
BLOCK_ERR parameter shows Out of service.
Initialization Manual (IMan): The output path is not complete (for example, the
cascade-to-slave path might not be open). In IMan mode, OUT tracks BKCAL_IN.
Out of Service (O/S): The block is not processed. The OUT status is set to Bad: Out of
Service. The BLOCK_ERR parameter shows Out of service.
(continued)
OCX 8800