Backplane Connector
Original instructions
About us
About Dual-Bus Backplanes
The dual-bus interface on the back of the BMENOR2200H module connects to the X Bus and Ethernet bus connectors across the backplane when you mount the module in the rack.
BMEXBP••0• backplanes are compatible with Modicon X80 modules in an M580 system.
Communications across the dual-bus backplane of this sample local rack (which includes an M580 CPU) implement both the Ethernet (red line) and X Bus (blue line) protocols:
NOTE:
  • BMXXPB••00 X Bus backplanes do not have connections that support eX80 modules.
  • Ethernet racks are described in detail in the Modicon M580, Hardware, Reference Manual.
Connection Protocols
The module supports communications over a BMEXBP••0• backplane using these protocols:
Bus
Description
X Bus
The module uses X Bus communications on the Ethernet backplane to obtain and exchange the following through the CPU:
  • configuration data for the module
  • application and diagnostic data
Ethernet
The module uses the Ethernet bus on the Ethernet backplane to manage connectivity to the module:
  • The module provides Ethernet connectivity to the CPU.
  • The module communicates with Ethernet communication modules on the local rack.
  • The module communicates with network devices that are attached to the external ports of the CPU.
The data exchange uses implicit messaging to facilitate memory sharing between the module and the CPU. For each CPU scan cycle, the CPU publishes all data at the same time to share the most current information with the RTU.
I/O Data Exchange with the CPU
Observe these maximum input and output sizes when the module exchanges I/O data with the CPU:
Protocol
Characteristics
DNP3 NET client
up to 64 slaves/servers (one session for each slave/server)
Memory consumption:
  • input data size: 8 Kb of data includes user-configurable data and 4K words of overhead. The overhead includes module diagnostic data, data object headers, and the number of headers depending on the user configuration. As a result, the maximum user-configurable input data size is approximately 7.55Kb (1Kb = 1024 bytes).
  • output data size: 8 Kb of data includes user-configurable data and 4K words of overhead. The overhead includes module control data, data object headers, and the number of headers depending on the user configuration. As a result, the maximum user-configurable output data size is approximately 7.56Kb (1Kb = 1024 bytes).
NOTE: The module supports a maximum of four master/client channels (including three virtual channels that share the same database of points with the master channel).
DNP3 NET server
Memory consumption:
  • input: 8 Kb
  • output: 8 Kb
NOTE: Refer to the descriptions above.
up to 150,000-event queue for all data types
up to 40,000 event queue for DNP3 SAv5 security events
supports clock synchronization from a master
service over TCP
client IP address validation list (up to 10 IP addresses)
four concurrent client connections with configurable TCP service port (default port is 20000)
event backup up to 10000 events
support for DNP3 secure authentication version 2 and version 5.
SAv2 and SAv5 work on both client and server sides.
Use this formula to achieve the recommended minimum MAST task cycle time per BMENOR2200H module:
Tcycle min= ((DataInB + 128)*2+(DataOutB + 32)) / 23500B/S)*30ms
The result is approximately a 30ms MAST task cycle with 8Kb in and 8Kb out.