Rockwell Automation 1771-PD PID MODULE (+DU) - Manual (Page 64)

Programming
Chapter 3
3Ć21
W18 (W38) B12 Error Limit. Reset to 0 inhibits error limiting. Set
to 1 the maximum negative error term for the loop is limited to the
value EMN in word W21 (W41). The maximum positive error is
limited to value EMP in word W22 (W42).
W18 (W38) B11 Dead Band. Reset to 0 inhibits dead band. Set to
1 enables the dead band feature using the value in word W23 (W43).
Refer to word W23 (W43) Dead Band.
W18 (W38) B10 Maximum Integral Term Limit. Reset to 0
inhibits integral term limiting. Set to 1 the value of the integral term
V
I
is limited to the maximum value V
I
MAX in word W26 (W46).
This limit applies to both the negative and positive excursions of the
integral term V I.
W18 (W38) B07, B06 Proportional Term Error. The setting of the
2-bit code determines which error signal will be used for the
proportional term V
P
calculation. The choices of the proportional
error term E
P
include straight error and error squared. Note that the
sign is retained. The error codes are listed in Table 3.D.
W18 (W38) B05, B04 Integral Term Error. The setting of the 2-bit
code determines which error signal will be used for the integral term
V
I
calculation. The choices of the integral error term E
I
include
straight error and error squared. Note that the sign is retained. The
error codes are listed in Table 3.D.
W18 (W38) B03 Derivative Term Error. Reset to 0 the error signal
is used in the derivative calculation. Set to 1 the process variable
signal is used.