
32
50.0
55.0
70
Actual –
Desired
Ratio
Deviation
OP1
0.0
bIAS
70
OP1
•1
Actual –
Desired
Ratio
Deviation
…2
OPERATOR LEVEL
2.10
Ratio Station (Templates 16 and 17)
The ratio station provides a set point for a subsequent slave controller. The wild variable (WV) is
weighted by ratio (
rAtO
) and bias (
bIAS
) values and is then retransmitted as an analog output value.
•1 Displayed only if enabled in Level B, Operator Configuration – see Section 5.7.
Actual Ratio
=
Process Variable (PV) – Bias
Wild Variable (WV)
Desired Ratio
Adjustable in local control only.
Ratio Setpoint Output
= (WV x Ratio) + Bias
[–10 to 110%]
Adjustable in manual control only.
Bias
[In engineering units]
Continued…
WV x
rAtO
+
bIAS
I/P3
Manual Output
OP1
I/P2
WV
rAtO
L
L
R
Local Ratio
•1 Template 17 only
Remote Ratio
Wild Variable
•1
Analog
Output
Profile Set Point
Fig. 2.9 Ratio Station