PLC Developers Guide /
Network Architecture
Each ConveyLinx-Ai Family Module communicates to its adjacent modules and to any connected PC or PLC via Ethernet physical media. All ConveyLinx-Ai Family Modules recognize (4) TCP/IP based protocols:
- Modbus TCP
- Profinet I/O
- Ethernet I/P
- CC-Link IEF Basic
Modbus TCP is the “native” protocol for communications between ConveyLinx-Ai Family Module and the EasyRoll / EasyRoll+ PC software. When ConveyLinx-Ai Family Module are used even for basic ZPA control with no external connections to a PC or PLC, they utilize Modbus TCP for inter-module communication.
Each ConveyLinx-Ai Family Module internal data structure is arranged and addressed as Modbus Holding Registers. The on-board communication and control processes attach logical meanings to each holding register and read and write data to specific registers to initiate and/or react to events. Certain registers contain information as to how the ConveyLinx-Ai Family Module is configured (MDR type, speed, direction, etc.) for its local controls. Other registers are used for inter-module communications for conveyor operation. For example, when an upstream ConveyLinx-Ai Family Module has a Carton ready to discharge to its neighboring downstream ConveyLinx-Ai Family Module, the upstream ConveyLinx-Ai Family Module will write a specific value to a specific address in the downstream ConveyLinx-Ai Family Module’s internal registers. The downstream ConveyLinx-Ai Family Module’s on board logic monitors these registers and knows that a specific value means that an upstream Carton is coming and to engage the proper control logic to convey the Carton.
Because ConveyLinx utilizes an open architecture (Modbus TCP) for inter-module communications; with proper definition and expected usage of certain register address locations, external control devices (PC’s and PLC’s) can easily interact with ConveyLinx-Ai Family Module to monitor and control various points along the conveyor path.