Publication 1762-RM001C-EN-P
Protocol Configuration E-9
Modbus™ RTU Slave
Protocol (MicroLogix
1200 Controllers and
MicroLogix 1500 Series
B and higher Processors
only)
This section shows the configuration parameters for Modbus RTU Slave
(Remote Terminal Unit transmission mode) protocol. For more
information about the Modbus Slave protocol, see the Modbus Protocol
Specification (available from http://www.modicon.com/techpubs/
).
The Modbus RTU slave driver maps the four Modbus data types—Coils,
Contacts, Input Registers, and Holding Registers—into four binary and/or
integer data table files created by the user. The coil and contact files can
contain up to 4096 coils or contacts in each register when the data table
file is configured for a maximum size of 256 words. The input register and
holding register files can contain up to 256 registers when the data table
file is configured for a maximum size of 256 words.
The modbus Memory map is summarized in Table E.4 and detailed in
Table E.5 below:
Table E.4 Modbus to MicroLogix Memory Map - Summary
(MicroLogix 1200 Controllers and MicroLogix 1500 1764-LSP Series B and 1764-LRP Processors only)
Modbus
Addressing
Description Valid MicroLogix Addressing
File Type Data File Number Address
0001 to 4096 Read/Write Modbus Coil Data space Bit (B) or Integer (N) 3 to 255 bits 0 to 4095
10001 to 14096 Read-Only Modbus Contact Data space Bit (B) or Integer (N) 3 to 255 bits 0 to 4095
30001 to 30256 Read-Only Modbus Input Register space Bit (B) or Integer (N) 3 to 255 words 0 to 255
30501 to 30532 Modbus Communication Parameters Communication Status File - -
31501 to 31566 Read-Only System Status File space Status (S) 2 words 0 to 65
40001 to 40256 Read/Write Modbus Holding Register space Bit (B) or Integer (N) 3 to 255 words 0 to 255
41501 to 41566 Read/Write System Status File space Status (S) 2 words 0 to 65
To Next Page
Loading...
Need help?
General
