Rockwell Automation 1395 Multi-Comm Hardware/Software - Manual (Page 13)

Chapter 3
Configuration & Interfacing
3–2
Parameter Table – A table which contains all parameters that are
available in the Drive and adapters.
Sink Parameter – Sink parameters accept data from other parameters
which is then used by the Drive to perform the
desired functions. An example of a sink is the ex
ternal velocity reference parameter which accepts a
speed reference from a device such as a PLC
Source Parameter – A parameter that contains real time information
that is available for use by other devices. These
devices can include PLC controllers, operator
interface devices, program terminals, etc.
Operation
The primary purpose of the MCA board is to allow the Drive to be directly
controlled by an Allen-Bradley PLC via RIO, or any other device which
can communicate using the DH+ protocol. This adapter has two Digital
communication channels which can be configured for connection to
Allen-Bradley RIO or Allen-Bradley DH+ links. Each channel is
independently programmable.
When a communication channel is configured for RIO connection, the
Adapter looks like a Remote I/O rack to an Allen-Bradley PLC Controller.
This allows the Drive to directly communicate to a PLC, without using
special modules or other programming interfaces. The MCA board
supports both Discrete I/O and block transfer mechanisms.
When a communication channel is configured for DH+ connection, the
Adapter board becomes a station on the DH+ link. Information can be
passed to and from the Drive using the DH+ protocol.
IMPORTANT: Data Highway + (DH+) is not designed for real time
control of data. Searching, monitoring large programs, and on-line
programming can degrade message throughput on this link since it can
perform only one of these functions at a time. Refer to the appropriate PLC
manual for details on the DH+ characteristics.
In addition to the communications channels the Adapter also has a separate
Discrete input whose function is defined by the user and a set of function
blocks which can be used to manipulate Adapter and/or Drive information.
Figure 3–1 presents an overview of the MCA board with a typical Channel
configuration. Channel A has been designated (via a dip switch) for RIO
protocol and Channel B has been designated for DH+ protocol. The
parameter numbers shown are for an MCA board mounted in Port B of the
Drive. This is the standard Port for the MCA Board.