Rockwell Automation 2711P Creating Modbus Applications - Manual (Page 67)

Publication 2711P-UM002B-EN-P - March 2007
Modbus/TCP Address Definitions 67
Mailbox Addressing Default types are shown in bold.
Arrays
Arrays are also supported for the holding register addresses. The
syntax for declaring an array (using decimal addressing) is 4xxxx[cols]
with assumed row count of 1 and 4xxxx[rows][cols].
For Word, Short and BCD arrays, the base address + (rows * cols)
cannot exceed 65536.
For Float, DWord, Long and Long BCD arrays, the base address +
(rows * cols * 2) cannot exceed 65535.
For all arrays, the total number of registers being requested cannot
exceed the holding register block size that was specified for this
device.
Mailbox Addressing
Decimal Addressing Hexadecimal Addressing
Type Word, Short, BCD
Format 4xxxxx H4yyyyy
Security Read/Write
Range 1 - 65536 1 - 10000
Type Boolean
Format 4xxxxx.bb H4yyyyy.c
Security Read/Write
Range xxxxx.0 - xxxxx.15 yyyyy.0 - yyyyy.F
Type Float, DWord, Long, LBCD
Format 4xxxxx H4yyyy
Security Read/Write
Range 1 - 65535 1 - FFFF