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New VersaMax® Modular Modbus Master Module
Product News Friday, April 28, 2006: CIMTEC Automation
New VersaMax Modular Genius NIU Modbus Master Module
The VersaMax Serial Communications Module, IC200CMM020, operates as a Modbus RTU Master in a VersaMax I/O Station controlled by a Genius Network Interface Unit. The serial Communications Module may be installed at any location in the I/O Station. Up to two Serial Communications modules can be used per I/O Station. This new module allows the user to easily connect to Modbus Slave devices remotely such as Variable Frequency Drives, Bar Code Readers, displays and much more.
Modbus RTU Communications
The VersaMax Serial Communications module supports Modbus RTU Master protocol. To operate as a Master, the Serial Communications module must receive commands from a remote host. For example, the remote host could be an RX7i PLC that communicates with the I/O Station’s VersaMax Genius NIU via a Genius Bus Controller module.
Commands from a Remote Host
The Serial Communications module exchanges commands with the remote host via the input and output memory areas of the I/O Station’s Genius NIU. The commands used for these communications are referred to as "memory mapped COMMREQs" because their format is similar to the existing GE Fanuc Modbus RTU COMMREQ (Communication Request) commands. These commands are defined in the document Modbus RTU Communications, GFK-2220C or later.
Commands from the remote host to the module are sent via %AQ memory. The module returns the command response in the first two %AI registers that have been configured for the module.
The Serial Communications module supports RTU Master command numbers 65520, 8000, 8001, 8002, and 8003 as described in the Modbus RTU Communications Manual, GFK-2220.
Compatibility: The Modbus Serial Master module is compatible with the VersaMax Genius NIU (IC200GBI001) only, no other VersaMax NIUs or VersaMax CPUs are supported at this time.
Flexibility: The Modbus Serial Master module is ideal for interfacing with a variety of third party Modbus Slave devices. The Genius NIU can easily be connected to any PAC or Series 90 controller.
- Water/Waste Water
- Pumping stations
- Lift stations
- Traffic control
- Ventilation systems
- Any application that has third party slave devices such as Variable Frequency Drives, marques, displays, controllers and other devices that communicate over Modbus serial.
- Remote interface to Modbus Serial devices over a Genius LAN
- Simple interface support to PAC controllers
- Support redundant LANs
VersaMax Micro 64 Ordering Information
|Serial Modbus Master Module
|Number of Serial Communications Modules
||Up to 2 per Genius NIU I/O Station
|Number of RTU slaves per Serial Communications Module
||1 to 247
|Serial Port Type
RS-485. 15-pin subminiature ‘D’ connector.
For RS-232 communications, an RS-485 to RS-232 adapter such as IC690ACC901 can be used. Adapter IC690ACC901 can be installed with its right-angle cable hanging down.
RS-485 supports both 2-wire and 4-wire electrical interfaces
|Baud Rate Supported
||1200, 2400, 4800, 9600, and 19200, and half or full duplex operation
|COMMREQ command memory (%AQ) required in the GENERIC_COMM module hardware configuration
||Depends on individual COMMREQ content.
Minimum: 22 words
Maximum: 64 words
|COMMREQ response memory (%AI) required
||Minimum: 2 words
Maximum: 64 words for Genius NIU
|RTU Master Commands
As described in Modbus RTU Communications Manual, GFK-2220. Minor differences as described below.
65520, Initialize RTU Master Port
8000, Clear RTU Master Dig. Status
8001, Read RTU Master Dig. Status
8002, Send RTU Read/Force/Preset Query
8003, Send RTU Diagnostic Query
||Open for orders
||VersaMax Modbus Master Serial Communications Module
Firmware and Software Requirements
No new firmware required on Genius NIU or CPU.
||VersaMax Serial Communications ModuleVersaMax Micro 64 Data Sheet
For more information, please contact:
Controllers Product Manager
Phone: (434) 978-5362
Fax: (434) 978-5205
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