Rockwell Automation 1771-PD PID MODULE (+DU) - Manual (Page 59)

Programming
Chapter 3
3Ć16
When set point scaling is selected, the data format should be 4-digit BCD.
Scaling can be selected by B16 = 1 in word W50 when expanded loop
features are selected by W01 B14 = 1. The sign bit W39 B07 and the x10
multiplier bit W19 B06 determine the range which can be +99990.
When scaling is selected, words W51 and W52 must contain the
minimum and maximum range values SMIN2 and SMAX2, respectively.
Refer to section 3.6.1 for additional information about scaling.
W14 Proportional Gain 2, Kp2 (Kc2). This word contains the
proportional gain constant for loop 2. The value is the same for A-B
(Kp2) or ISA (Kc2), selected by W02 B00. Data format is 4-digit BCD
(99.99 dimensionless) with implied decimal point. Multiplier bits W19
B04, B05 can be selected for X1, divided by 10, x10, x100 (Table 3.F,
Multiplier Codes). By using multipliers, the range can be extended from
0.000 to 9999.
W15 Bias 2, BIAS2. When using only standard loop features, the loop
bias is the value stored in this word. when expanded loop features are
selected by W01 B14 = 1, either the feedforward term FFV or the value
stored is this word can be used as the loop bias. The feedforward term is
normally used unless W50 B02 = 1 which sets the bias to the value stored
in this word.
The data format is 4-digit BCD, range 0000 to 9999. When the expanded
loop features are selected, the negative bias bit W50 B01 = 1 allows a full
scale range of +9999.
W16 Set Process Variable 2, SET PV2. The value stored in this word is
used by the PID module as the process variable for loop 2 when W38 B15
= 1. Normally, the PID module uses the hardware analog input value
when W38 B15 = 0. Data format in 4 digit BCD or 12-bit binary. format
is selected by W01 B12. Range is 0000 to 4095.
W17 Set Feedforward Input 2, SET FF12. (XF) The value stored in
this word is used by the PID module as the feedforward input when W50
B13 = 1. Normally, the PID module uses the tieback input 2 value as the
feedforward input when W50 B13 = 0. This word can be used only when
expanded loop features are selected by W01 B14 = 1. Data format is
4-digit BCD or 12-bit binary. Format is selected by W01 B12. The range
is 0000 to 4095.