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Rosemount Model 8800C Vortex Flowmeter with FOUNDATION
TM
Fieldbus
C-2
To further customize the block for use in your application, you can
configure filtering, feedforward inputs, tracking inputs, setpoint and
output limiting, PID equation structures, and block output action.
Table C-1 lists the PID block parameters and their descriptions, units of
measure, and index numbers, and Figure C-1 on page C-5 illustrates
the internal components of the PID function block.
TABLE C-1. PID Function Block System Parameters.
Parameter
Index
Number
Units Description
ACK_OPTION 46 None Used to set auto acknowledgment of alarms.
ALARM_HYS 47 Percent The amount the alarm value must return to within the alarm limit before the
associated active alarm condition clears.
ALARM_SUM 45 None The summary alarm is used for all process alarms in the block. The cause of the
alert is entered in the subcode field. The first alert to become active will set the
Active status in the Status parameter. As soon as the Unreported status is cleared
by the alert reporting task, another block alert may be reported without clearing the
Active status, if the subcode has changed.
ALERT_KEY 04 None The identification number of the plant unit. This information may be used in the host
for sorting alarms, etc.
ALG_TYPE 74 None Selects filtering algorithm as Backward or Bilinear.
BAL_TIME 25 Seconds The specified time for the internal working value of bias to return to the operator set
bias. Also used to specify the time constant at which the integral term will move to
obtain balance when the output is limited and the mode is AUTO, CAS, or RCAS.
BIAS 66 EU of OUT_SCALE The bias value used to calculate output for a PD type controller.
BKCAL_HYS 30 Percent The amount the output value must change away from the its output limit before limit
status is turned off.
BKCAL_IN 27 EU of OUT_SCALE The analog input value and status from another block’s BKCAL_OUT output that is
used for backward output tracking for bumpless transfer and to pass limit status.
BKCAL_OUT 31 EU of PV_SCALE The value and status required by the BKCAL_IN input of another block to prevent
reset windup and to provide bumpless transfer of closed loop control.
BLOCK_ALM 44 None The block alarm is used for all configuration, hardware, connection failure, or system
problems in the block. The cause of the alert is entered in the subcode field. The first
alert to become active will set the active status in the status parameter. As soon as
the Unreported status is cleared by the alert reporting task, and other block alert
may be reported without clearing the Active status, if the subcode has changed.
BLOCK_ERR 06 None This parameter reflects the error status associated with the hardware or software
components associated with a block. It is a bit string so that multiple errors may
be shown.
BYPASS 17 None Used to override the calculation of the block. When enabled, the SP is sent directly
to the output.
CAS_IN 18 EU of PV_SCALE The remote setpoint value from another block.
CONTROL_OPTS 13 None Allows you to specify control strategy options. The supported control options for the
PID block are Track enable, Track in Manual, SP-PV Track in Man, SP-PV Track in
LO or IMAN, Use PV for BKCAL_OUT, and Direct Acting
DV_HI_ALM 64 None The DV HI alarm data, which includes a value of the alarm, a timestamp of
occurrence, and the state of the alarm.
DV_HI_LIM 57 EU of PV_SCALE The setting for the alarm limit used to detect the deviation high alarm condition.
DV_HI_PRI 56 None The priority of the deviation high alarm.
DV_LO_ALM 65 None The DV LO alarm data, which includes a value of the alarm, a timestamp of
occurrence, and the state of the alarm.
DV_LO_LIM 59 EU of PV_SCALE The setting for the alarm limit use to detect the deviation low alarm condition.
DV_LO_PRI 58 None The priority of the deviation low alarm.
ERROR 67 EU of PV_SCALE The error (SP-PV) used to determine the control action.
FF_ENABLE 70 None Enables the use of feedforward calculations
FF_GAIN 42 None The feedforward gain value. FF_VAL is multiplied by FF_GAIN before it is added to
the calculated control output.