Rockwell Automation 1771-PD PID MODULE (+DU) - Manual (Page 89)

Programming
Chapter 3
3Ć46
W61(W68)B00 Algorithm Output>Maximum Output. Reset to 0
indicates that the analog output is in range and less than or equal to
the maximum output value VMAX in word W29(W49). Set to 1
indicates that the analog output computed by the PID module is
greater than VMAX. The bit status is reported whether or not output
limiting has been selected. This status bit does not monitor a SET
OUT value downloaded from the PC processor into word
W05(W12).
W62(W69) Loop Error, ERROR. This word contains the loop error.
Data format is 4-digit BCD. The sign bit B17 in word W61(W668) can
establish an unscaled range of 0 to +4095.
When error scaling is selected by W30(W50)B15 = 1, the loop error can
be reported in user-selected engineering units. The sign bit B17 in word
W61(W68) and the x 10 multiplier bit B06 in word W19(W39) must be
examined to determine the value. The scaled range can be +99990. Refer
to section titled Scaling.
W63(W70) Read Loop Output, READ V. This word contains the final
analog output value as determined by the module’s PID algorithm. Data
format is 4-digit BCD or 12-bit binary. Format is selected by W01 B12.
Range is 0000 to 4095.
NOTE: When a SET OUT value is downloaded from the PC processor
into word W05(W12) by setting W01 B01(W01 B02) = 1, the SET OUT
value will override the analog output value. However, the value reported
in W63(W70) will always be the analog output value as determined by the
module’s PID algorithm, not the SET OUT value.
W64(W71) Read Analog Input, READ IN. This is the actual input
value read by the analog-to-digital converter in the module. Data format
is 4-digit BCD or 12-bit Binary. Format is selected by W01 B12. Range
is 0000 to 4095.
W65(W72) Read Process Variable, READ PV. This is the actual
process variable used by the PID module. Data format is 4-digit BCD.
The unscaled range is 0000 to 4095.
When process variable scaling is selected by W30(W50)B17 = 1, READ
PV can be reported in user-chosen engineering units. The sign bit B16 in
word W61(W68) and the x10 multiplier bit B06 in word W19(W39) must