DF1 protocol
●It goes about the communication protocol designated for the classic serial link (RS232/RS422). The protocol allows the communication of either Full-duplex (point-to-point type of connection, RS232) or Half-duplex with addressing the PLC stations. This protocol is supported by devices that work with data areas (Data File).
●Example: SLC 500, Micrologix, etc.
Ethernet/IP protocol
●It is built on the NetLinx architecture that is implemented even in DeviceNet and ControlNet networks. Ethernet/IP is administered by the ODVA independent organization that even takes charge of DeviceNet. This protocol is supported by devices that work with data objects (contrary to the data areas in DF1 protocol).
●Example: Micro 820, controlLogix, compactlogix, softlogix, drive logix, guardlogix, etc.
Modbus protocol
●Modbus is a standard, very commonly used protocol for the serial link and Ethernet (the PLC is slave). The Modbus RTU protocol is supported for example by: Micro820, MicroLogix 1200/1100/1500. The Modbus TCP/IP protocol is supported.
●Example: Micro 820, Micrologix 1400.
ASCII protocol
●It goes about the configurable char communication protocol designated for the classic serial link (RS232/RS422). This protocol is supported by some PLC’s.
●For example Micro 820, compactlogix (on the second serial link port), micrologix 1100/1200/1500, etc.
DH+ protocol
●It supports 64 nodes at the most, 230 kB/s (SLC 501 to 3 can’t it). It is the proprietary Allen- Bradley protocol. Two methods can be used for communication.
DH485 protocol
●It goes about the communication protocol designated for the serial link. It supports 32 nodes at the most, 19 kB/s (multi-master = each- to-each). It is the proprietary Allen-Bradley protocol. Two methods can be used for communication.
