Emerson Rosemount OCX 8800 Reference Manual page 183

The nine arithmetic functions are: flow compensation linear, flow compensation square
root, flow compensation approximate, BTU flow, traditional multiply and divide, average,
summer, fourth order polynomial, and simple HTG compensate level.
This arithmetic function block supports mode control (Auto, Manual, Out of Service). There
is no standard alarm detection in this block.
Table 7-30: Arithmetic (ARTHM) block
Index number Parameter
4 ALERT_KEY
29 ARITH_TYPE
30 BAL_TIME
31 BIAS
21 BIAS_IN_1
23 BIAS_IN_2
25 BIAS_IN_3
36 BLOCK_ALM
6 BLOCK_ERR
27 COMP_HI_LIM
28 COMP_LO_LIM
32 GAIN
22 GAIN_IN_1
24 GAIN_IN_2
26 GAIN_IN_3
12 GRANT_DENY
Reference Manual
Units Description
None The identification number of the plant unit. This informa-
tion may be used in the host for sorting alarms, etc.
None The set of 9 arithmetic functions applied as compensation
to or augmentation of the range extended input.
Seconds Specifies the time for a block value to match an input, out-
put, or calculated value or the time for dissipation of the
internal balancing bias.
None The bias value.
None The bias value for IN_1.
None The bias value for IN_2.
None The bias value for IN_3.
None This 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, another block alert may be repor-
ted without clearing the Active status, if the subcode has
changed.
None The summary of active error conditions associated with
the block. The possible block errors are Block config-
uration error, Simulate active, Local over-
ride, Input failure/process variable has
Bad status, Output failure, Readback failed,
Out of service, and Other. Each function block re-
ports none or a subset of these error conditions.
EU of PV Determines the high limit of the compensation input.
EU of PV Determines the low limit of the compensation input.
None The proportional gain (multiplier) value.
None The proportional gain (multiplier) value for IN_1.
None The proportional gain (multiplier) value for IN_2.
None The proportional gain (multiplier) value for IN_3.
None Options for controlling access of host computers and local
control panels to operating, tuning, and alarm parameters
of the block. Not used by the device.
Foundation Fieldbus
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