AVEVA™ Plant SCADA

Allen-Bradley PLC-3 via Data Highway - Data Types

Save PDF

Allen-Bradley PLC-3 via Data Highway - Data Types

Save PDF

Last UpdatedAug 01, 2025
3 minute read

Note: The Allen-Bradley PLC-3 has many data types. The driver makes a separate request for each different data type, and each request has a finite overhead. It is more efficient to read fewer data types, so you should move the I/O and other data into a few main blocks to be read by Plant SCADA.

Data Types	Address Format	Plant SCADA Data Type
Output image	Of:O/o (f is optional)	DIGITAL
Input image	If:O/o (f is optional)	DIGITAL
Timer Control bits	TCTL:w/t	DIGITAL
Timer Control bits	TCTL:w/o	DIGITAL
Timer Preset bits	TPRE:w/o	DIGITAL
Timer Accumulator bits	TACC:w/o	DIGITAL
Counter Control bits	CCTL:w/t	DIGITAL
Counter Control bits	CCTL:w/o	DIGITAL
Counter Preset bits	CPRE:w/o	DIGITAL
Counter Accumulator bits	CACC:w/o	DIGITAL
ASCII	Af:w/o	DIGITAL
BCD	Df:w/o	DIGITAL
REAL	Ef:w/o (o = 0 to 37)	DIGITAL
LONG	Hf:w/o (o = 0 to 37)	DIGITAL
Integer	Nf:w/o	DIGITAL
Binary	Bf:w/o	DIGITAL
Status words	Sf:w/o	DIGITAL
Pointer Section and File	PFIL:w/o	DIGITAL
Pointer word	PWRD:w/o	DIGITAL
Output image	Of:O (f is optional)	BCD / INT
Input image	If:O (f is optional)	BCD / INT
Timer Control	TCTL:w	BCD / INT
Timer Preset	TPRE:w	BCD / INT
Timer Accumulator	TACC:w	BCD / INT
Counter Control	CCTL:w	BCD / INT
Counter Preset	CPRE:w	BCD / INT
Counter Accumulator	CACC:w	BCD / INT
Integer	Nf:w	BCD / INT
BCD	Df:w	BCD / INT
Binary	Bf:w	BCD / INT
ASCII	Af:w	BCD / INT
Status words	Sf:w	BCD / INT
Pointer Section and File	PFIL:w	BCD / INT
Pointer word	PWRD:w	BCD / INT
Long	Hf:w	LONG / LONGBCD
Floating Point	Ff:w	REAL

Where:

n =	Optional Module Number 0 to 8 decimal
f =	File Number 0 to 999 decimal
:w =	Element Number 0 to 9999 decimal
:O =	Element Number 0 to 7777 octal
/o =	Bit Number 0 to 17 octal PRE = Preset Value ACC = Accumulated Value
.C =	Control Sub Element LEN = Length POS = Position
.P =	PID Sub Element SP = Set Point KP = Proportional Gain KI = Integral Gain KD = Derivative Gain BIAS =Output Bias % MAXS = Maximum Scaled Value MINS = Minimum Scaled Value DB = Deadband SO = Set Output % MAXO = Maximum Output % MINO = Minimum Input % UPD = Update Time PVH =PV Alarm High PVL = PV Alarm Low PVDB = PV Alarm Deadband PV = Process Variable ERR = Error OUT = Output DVP = Deviation Alarm + DVN =Deviation Alarm - DVDB = Deviation Alarm Deadband MAXI = Maximum Input MINI =Minimum Input TIE = Tieback %
.t =	Timer bits EN = Enable TT = Timing DN =Done BS LK
.c =	Counter bits CU =Count Up CD = Count Down DN = Done OV = Overflow UN = Underflow LK
.r =	Control bits EN = Enable EU = Enable Unloading DN = Done EM = Empty ER = Error UL = Unload IN = Inhibit Comparisons FD = Found
.p =	PID bits EN = Enable CT = Cascaded Type CL = Cascaded Loop PVT = PV Tracking DO = Derivative Of SWM = Software A/M Mode CA = Control Action MO = Mode PE = PID Equation INI = PID Initialized SPOR = SP Out of Range OLL = Output Limit Low OLH = Output Limit High EWD = Error Within Deadband DVPA = Deviation Low Alarm DVNA = Deviation High Alarm PVLA = PV Low Alarm PVHA = PV High Alarm

Examples

Data Type	DIGITAL
Address	I:1/15
Comment	Input Image - Element Number 1 / Bit Number 15

Data Type	INT
Address	N7:3
Comment	Integer - File Number 7 : Element Number 3

Allen Bradley 3 PLCs support remapping reads and writes.

AVEVA™ Plant SCADA

Allen-Bradley PLC-3 via Data Highway - Data Types

Table of Contents

Allen-Bradley PLC-3 via Data Highway - Data Types

Related Links