ProSoft Technology MVI56-DFCMR - Manual (Page 65)

Reference MVI56-DFCMR ♦ ControlLogix Platform
DF1 Interface Module with Reduced Data Block
ProSoft Technology, Inc. Page 65 of 113
October 20, 2008
DF1 Master Protocol Specifications
The ports on the DF1 module can be individually configured as Master ports.
When configured in master mode, the DFCM module is capable of reading and
writing data to remote DF1 devices, enabling the processor to act as a SCADA
sub-master.
ƒ
Command List: Up to 100 commands per Master port, each fully-configurable
for function, slave address, register to/from addressing and word/byte count
ƒ Status Data: Error codes available on an individual command basis. In
addition, a slave status list is maintained per active master port
ƒ Polling of Command List: User-configurable polling of commands, including
disabled, continuous, and on change of data (write only)
DF1 Slave Protocol Specifications
The module accepts DF1 commands from an attached DF1 master unit. When in
slave mode, the module can accept DF1 commands from a master to read/write
data stored in the module's internal registers. This data can be derived from other
DF1 slave devices on the network through a master port or from the processor
and is easily transferred to the processor's data registers.
Tested Hardware Connections
Several hardware connections have been tested by ProSoft Technology or have
been customer field tested. The following physical connections have been tested
successfully:
ƒ
RA Panel view (Full Duplex point-point, DFCM as slave)
ƒ RA Processors (Full/Half duplex, DFCM as either master or slave)
ƒ RA Power Monitors (485 Half-Duplex DFCM as Master)
5.2 Functional Overview
This section provides an overview of how the MVI56-DFCMR module transfers
data using the DFCMR protocol. You should understand the important concepts
in this chapter before you begin installing and configuring the module.
5.2.1 General Concepts
The following discussion explains several concepts that are important for
understanding the operation of the MVI56-DFCMR module.
Module Power Up
On power up the module begins performing the following logical functions:
1 Initialize hardware components
o
Initialize ControlLogix backplane driver
o
Test and Clear all RAM
o
Initialize the serial communication ports
2 Wait for Module Configuration from ControlLogix processor