Delta RMC101 - Manual (Page 442)

RMC100 and RMCWin User Manual
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5.3.6 Modbus Plus Global Data
5.3.6.1 Using Modbus Plus Global Data
Note: Global data should be used in all applications; it is not only for advanced users.
You should first familiarize yourself with the standard method of reading and writing to a slave
from a master, as described in Reading and Writing Modbus Plus Registers. Global data greatly
speeds up the time required for a master to retrieve data from a slave such as the RMC.
Each node may send up to 32 registers of global data as it passes the token to the next node on
the network. All nodes on the network receive this data and store it in an internal database.
Therefore, whenever a node wants to know the global data of a particular node, all it has to do is
look in its internal database, which gets updated automatically.
The RMC always broadcasts 32 registers of global data. The user can select which data will be
included in the 32 registers of global data. For details on assigning the global data registers, see
Using the Status Map Editor.
For a list of the default global data register mapping, see Default Status Map Data.
There are two methods of reading Global Data into the Modicon PLC:
• Use the MSTR Modicon Ladder Logic Block to explicitly read the global data. Using this method,
you are limited to reading the global data into holding registers only.
• Use Modicon’s Peer Cop feature. This method works better in most applications, but takes more
time to set up. See Using Modicon’s Peer Cop to Read Global Data topic.
5.3.6.2 Using Modicon’s Peer Cop to Read Global Data
Peer Cop Overview
Modicon’s Peer Cop feature is a method of having data read and written to and from remote
nodes at the top of each PLC scan. Either of Modicon’s Modsoft® and Concept® software
packages can be used to configure Peer Cop.
Peer Cop supports four types of automatic data transfers:
• Specific Inputs
• Specific Outputs
• Global Inputs
• Global Outputs
Of these four types, only Global Inputs are supported by the RMC. Global inputs refer to the
global data sent out by other devices, such as the RMC. Modsoft and Concept allow the user to
select which of the Global Data registers get copied to which Modicon PLC registers.
The following steps are required to set up Peer Cop. The exact details are not described as they