Modbus Communication

Please send me Mod bus Communication Sample program in Rslogix 500...id - [email protected]

Please look at an Anybus Communicator, this makes communication with Modbus much easier. You get your data right in a pre-defined register, and don't have to program all those different commands to read or write data.

Jack

Or "ProSoft" see link below.

http://www.prosoft-technology.com/p...l_automation/protocol/serial/modbus/mvi46_mcm

Allen Bradley Knowledgebase article number 33774 shows a Modbus setup for communicating to Powerflex drives using the units with Modbus capability. Of course the addresses you use would depend on the device you wish to communicate with. Examples of the setup of the Message commands is given. We use this method to communicate with various devices including the Powerflex drives.

I have used the ProSoft card. It is easy with their manual and the sample program just works.

I used the ModSim software for testing at my desk. http://www.win-tech.com/html/demos.htm

He doesn't specify which PLC, type of modbus or if he wants it to be a master or a slave. If it's a micrologix that he wants on a RTU network he doesn't need any additional 3rd party devices. And if it's an ML1400 rev. B, it will even talk modbus TCP

Modbus and the SLC/MicroLogix family controllers

A brief summary of Modbus and the SLC-500/MicroLogix family controllers:

The SLC-5/03, SLC-5/04, and SLC-5/04 modular controllers all support Modbus RTU Master on their RS-232 serial ports.

The MicroLogix 1100, 1200, 1400, and 1500 controllers support both Modbus RTU Master and Modbus RTU Slave on their RS-232 serial ports.

The MicroLogix 1100 and 1400 controllers also support Modbus RTU on their RS-485 serial ports, which are wired to the same connector as the RS-232 port.

MicroLogix 1400 Series B controllers support Modbus/TCP protocol as a peer-to-peer messaging protocol.

I have not included firmware revisions that support these features; all MicroLogix controllers can be updated in the field at no charge, but SLC-500 controllers require a purchased firmware kit.

If the OP responds with details about what he wants (master or slave, SLC or MicroLogix) we can point him to the correct user manual.