Delta RMC101 - Manual (Page 315)

Ethernet 5.2
Communications 5-65
5.2.6 Controlling and Monitoring the RMC over Ethernet
5.2.6.1 Allen-Bradley Controllers
5.2.6.1.1 Using Allen-Bradley Controllers with the RMC Ethernet Module
Allen-Bradley has several Ethernet options for its PLCs. The SLC 5/05 and Ethernet PLC-5E
controllers each have a built-in Ethernet port. The ControlLogix uses the 1756-ENET or 1756-
ENBT communication module to use Ethernet, and PLC-5 controllers other than the PLC-5E can
have Ethernet added using a PLC-5 Ethernet Interface Module. Allen-Bradley also sells a PC-
based controller called the SoftLogix 5, which can also communicate with the RMC.
Note: Ethernet communication with the ControlLogix Ethernet (e.g. 1756-ENET and 1756-
ENBT) modules requires RMC ENET firmware dated 20000420 or later.
In addition to Allen-Bradley's controllers, SoftPLC Corporation manufactures a PC-based, PLC-5
compatible controller that can also communicate with the RMC. See Using the SoftPLC with the
RMC Ethernet Module for details.
All of these PLCs can the same ladder logic block to communicate over the Ethernet: the
Message (MSG) block. This block takes a number of parameters, which are briefly described
below. For a complete description of the parameters, refer to Allen-Bradley's Instruction Set
Reference Manual for the appropriate PLC.
Note: With the introduction of the 1756-ENET/B and 1756-ENBT/A, the ControlLogix now also
supports I/O connections through EtherNet/IP, which greatly improves performance and
determinism. When using the ControlLogix, you will most likely want to use both the MSG block
and I/O. EtherNet/IP is discussed in detail in a number of topics starting with Using EtherNet/IP
with the RMC ENET.
The Allen-Bradley PLCs can read or write from registers in compatible remote devices such as
other Allen-Bradley PLCs or the RMC. The RMC emulates a PLC-5 with 248 integer files (N7 and
N8-N255) with 256 elements each (0-255), all of which are accessible over the Ethernet from the
Allen-Bradley PLCs. See the RMC Register Map (Allen-Bradley) for details on those registers and
their addresses.
Note: Although the RMC Register Map is spread out over 248 integer files, reads and writes that
extend beyond the end of an RMC register file will continue into the next file or files. This is
particularly useful on the ControlLogix, which allows reading large amounts of data with a single
MSG block. By reading 2048 integers from N9:0 in the RMC, the entire Event Step table can be
read into the ControlLogix, even though it uses N9 through N17.
If you need help setting up your network, either consult your network administrator, or for simple
stand-alone networks, see Setting up a Stand-alone TCP/IP Control Network.
MSG parameters:
The MSG block has slightly different parameters depending on the controller and programming
software you are using. The parameters used by RSLogix 5 version 3.2.0.0, RSLogix 500 version
3.01.02.00, and RSLogix 5000 version 2.27.00 for the PLC-5, SLC 5/05, and ControlLogix
controllers respectively are described below. The SoftLogix 5 parameters are similar.
SLC 5/05 MSG Block Parameters:
The SLC 5/05 MSG block is displayed as the following: