Modus Plus communication: General
Introduction
Introduction Modbus Plus communication is used to exchange data between all devices connected by the bus.
The Modbus Plus protocol is based on the principle of a logical token bus (Logical
Token passing). Each station of one network is identified by an address between 1 and 64 and each station accesses the network after reception of a token. Duplicated addresses are not valid.
Network example
Modbus Plus
2 12
Premium Quantum
Token bus (logic ring)
Associated manuals
A Modbus Plus communication channel comprises three main functions: l point to point data exchanges via the messaging service, using the Modbus protocol, l broadcast exchanges of global data between all the stations participating in this exchange, l multidrop exchanges of specific data via the Peer Cop services.
If you require further information you should consult the following manuals:
Title
Modbus Plus Network - Installation and planning manual
TSX Micro PLCs - Installation manual
Premium TSX PLCs - Installation manual
Description
Detailed description of the set-up procedure for the Modbus Plus network
Hardware installation
Hardware installation
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Modus Plus communication: General
Compatibility
Hardware
Software
This type of communication is available for PLCs of at least version V3.0: l l
TSX Premium via the intermediary of the TSX MBP100 PCMCIA card,
TSX Micro accepting the PCMCIA card described below.
Note: This type of communication is not available with TSX SCY 21601 modules.
TSX Premium and Micro PLCs do not support redundancy with the TSX MBP 100 card.
The PCMCIA TSX MBP 100 card can process 4 communication functions at the same time.
The maximum size of the number of objects per communication function is 125 useful data words (maximum frame of 256 bytes).
In the event of communication of a TSX Premium and Micro PLC with a TSX
Quantum PLC, it is necessary to shift addressing. To access a Quantum object with address n, the communication function on the Premium side must have the address n-1.
The Peer Cop service is only supported by TSX Premium PLCs.
During configuration of inputs and outputs for the Peer Cop service, it is possible to allocate up to 32 internal words to each connection point in the local bus. The total number of words must not exceed 500 internal words.
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