Rockwell Automation 1771-PD PID MODULE (+DU) - Manual (Page 75)

Programming
Chapter 3
3Ć32
W30(W50)B04 Minimum Scaling Sign. (XF) Reset to 0 the sign
for SMIN in word W32(W51) is positive. Set to 1 the sign is
negative.
W30(W50)B03 Maximum Scaling Sign. (XF) Reset to 0 the sign
for SMAX in word W32(W52) is positive. Set to 1 the sign is
negative.
W30(W50)B02 Source of Bias. (XF) Reset to 0 the feedforward
value is the loop bias. Set to 1 the bias value in word W08(W15) is
the loop bias.
W30(W50)B01 Bias (FFV) Sign. (XF) Reset to 0 the sign of the
feedforward/bias term remains the same. Set to 1 the sign is
reversed.
W30(W50)B00 Cascade. (XF) Reset to 0 inhibits the cascade
feature. Set to 1 cascades the calculated output of loop 1 into the set
point of loop 2. (W50 B00 for loop 2 must be reset to 0). Refer to
section titled Closed Loop Control for additional information about
cascading.
W31(W51) Minimum Scaling Value SMIN. (XF) This word contains
the minimum (or bottom) scale value of the loop scaling algorithm. This
value is in engineering units. Data format is 4-digit BCD (9999
maximum). The sign bit B04 in word W30(W50) and the x10 multiplier
bit B06 in word W19(W39) must be considered to determine the value.
The range can be +99990. Refer to section titled Scaling for additional
information about scaling.
W32(W52) Maximum Scaling Value, SMAX. (XF) This word contains
the maximum (or top) scale value of the loop scaling algorithm. This
value is in engineering units. Data format is 4-digit BCD (9999
maximum). The sign bit B03 in word W30(W50) and the x10 multiplier
bit B06 in word W19(W39) must be considered to determine the value.
The range can be + 99990. refer to section titled Scaling for additional
information about scaling.
W33(W53) Feedforward Offset, FFO. (XF) This word contains the
feedforward offset of the loop. It is added to the feedforward input. Data
format is 4-digit BCD (9999 maximum).