help on DF1 driver - Data table allocation of PLC (SLC 500)


Thread Starter

Sandeep Shroff

Hello list,

I am developing a DF1 driver for SLC 500 (in particular SLC 5/03) PLC.

I am a novice in PLC programming but have an extensive exposure of the
instrumentation & DCS programming.

I am looking out looking out for information on the Data table allocation of this PLC(SLC 500 (in particular SLC 5/03)). Also I am interested in knowing what type of addressing is used for accessing the files of the PLC ------ that is whether physical (octal, Hex, etc..) addressing or logical addressing has to be used for accessing the files of the PLC.

Please let me know any documentation or help available on the net for the same and especially related to the driver development.

Thanking you in anticipation

Sandeep Shroff
Sandeep Shroff
Sr. Consultant
Remote & Embedded Technologies

rapidEffect (P) Ltd. 25, Napier Road, Pune 411001, India
Tel./Fax. +91-20-6363250

John Midgley

The following is taken from Allen Bradley's SLC500 reference manual:

O:e.s/b Where 'e' is the slot number (decimal). Slot 0, adjacent to the power supply in the first chassis, applies to the processor module (CPU). Succeeding slots are I/O slots, numbered from 1 to a max of 30.

O:3/15 = Output 15, slot 3
O:5/0 = Output 0, slot 5
O:10/11 = Output 11, slot 10
I:7/8 = Input 8 , slot 7
I:2.1/3 = Input 3, slot 2, word 1

Word addresses
O:5 = Output word 0, slot 5
O:5.1 = Output word 1, slot 5
I:8 = Input word 0, slot 8

Default values: Your programming device will display an address more formally. For example, when you assign the address O:5/0, the programming devive will show it as O:5.0/0 (Output file, slot 5, word 0, terminal 0).

Hope this helps. If not try they have online manuals.

Regards John!
You can find the DF 1 Protocol and Command Set manual in pdf format at:-
go to manuals online

go to Communication Networks

go to protocol

DF 1 Protocol and Command Set is the only protocol and can be viewed using Acrobat Reader