Allen-Bradley 1785 PLC-5 - PID Control Structure and Mnemonics

Addressing Reference
1785 PLC-5
21
Mnemonic
Structure Member Size PLC Data Type
.DVDB Deviation Alarm Dead Band 4 bytes IEEE float
.MAXI Input Range Maximum 4 bytes IEEE float
.MINI Input Range Minimum 4 bytes IEEE float
.TIE Tieback % 4 bytes IEEE float
.ADDR[
1
] Address of Master for the Slave 4 X 2 bytes signed words
.DATA[
2
] Reserved/Internal Use 14 X 4 bytes IEEE float
1
0 – 3
2
0 – 13
Figure 20
PID Control Structure in PD file
15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
EN CT CL PVT DO SWM CA MO PE
INI SPOR OLL OLH EWD DVNA DVPA PVLA PVHA
SP Set Point 4 bytes IEEE float
KP Proportional Gain 4 bytes IEEE float
KI Initial Gain 4 bytes IEEE float
KD Derivative Gain 4 bytes IEEE float
BIAS Output Bias % 4 bytes IEEE float
MAXS Maximum Scaled Value 4 bytes IEEE float
MINS Minimum Scaled Value 4 bytes IEEE float
DB Dead Band 4 bytes IEEE float
SO Set Output % 4 bytes IEEE float
MAXO Maximum Output Limit 4 bytes IEEE float
MINO Minimum Output Limit 4 bytes IEEE float
UPD Update Time 4 bytes IEEE float
PV Process Variable 4 bytes IEEE float
ERR Error: Scaled 4 bytes IEEE float
OUT Output 4 bytes IEEE float
PVH PV Alarm High 4 bytes IEEE float
PVL PV Alarm Low 4 bytes IEEE float
DVP Deviation Alarm + 4 bytes IEEE float
DVN Deviation Alarm – 4 bytes IEEE float
PVDB PV Alarm Dead Band 4 bytes IEEE float
DVDB Deviation Alarm Dead Band 4 bytes IEEE float
MAXI Maximum Input 4 bytes IEEE float
MINI Minimum Input 4 bytes IEEE float
TIE Tieback % 4 bytes IEEE float
ADDR [0] thru Master-to-Slave Address 8 bytes signed words
ADDR [3]
DATA [0] thru Reserved / Internal Use 14 X 4 bytes IEEE float
DATA [13]