BASEstartm Open DAS
for Allen-Bradley Data Highwaytm
on Tru64tm UNIX
Installation and User's Guide


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3.3.3 PLC-5 Addressing Syntax and Supported Data Types

This section describes legal data table addresses and data types for the 1785 PLC-5 family. For information on addresses and supported data types for the PLC-5/250 PLC, refer to Section 3.3.4.

The structure of a legal data table address for the PLC-5 differs depending on the table that is being addressed. The PLC-5 supports the following data table sections:

I - Input
O - Output
S - Status
B - Binary
T - Timer
C - Counter
R - Control
N - Integer
F - Floating-Point
A - ASCII
D - Decimal
ST - String
SC - SFC Status
BT - Block-Transfer Control
TD - Token Data
PD - PID Control
MG - Message Control

Figure 3-10 shows the structure of a legal I/O data table address for the PLC-5.

Table 3-13 shows examples of legal I/O data table addresses for the PLC-5.

Figure 3-10 PLC-5 I/O Data Table Address Format


Table 3-13 Example PLC-5 I/O Data Table Addresses
Example Address MMS Type1 Description
I:20 UNSIGNED_16 Input image rack 2 group 0 octal
I:277 INTEGER_16 Input image rack 27 group 7 octal
I:177/17 BIT_STRING Bit 17 of rack 17 group 7 octal
$O:77/1 BIT_STRING Bit 1 of rack 7 group 7 octal
I:0 Array of 10 UNSIGNED_16 Ten words beginning at rack 0 group 0


1Arrays are supported. Structures are not supported. Variable size arrays are not supported.


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