ProSoft Technology 5202-DFNT-DFCM4 - Manual (Page 38)

DFCM Protocol Configuration DFCM ♦ ProLinx Gateway
Driver Manual DF1 Master/Slave
Page 38 of 88 ProSoft Technology, Inc.
October 15, 2010
6.5 [DF1 PORT x COMMANDS]
The [DF1 PORT 0 COMMANDS], [DF1 PORT 1 COMMANDS], [DF1 PORT 2
COMMANDS] and [DF1 PORT 3 COMMANDS] sections of the CFG file set the
serial master port command lists. These lists poll slave devices attached to the
master ports. The module supports numerous commands.
The command list is formatted differently than the other sections of the
configuration file. Commands are present in a block between the labels START
and END. These labels inform the program where the list resides. The module's
program will parse all commands after the START label until it reaches the END
label.
6.5.1 Command List Overview
In order to interface the ProLinx module with slave devices, you must construct a
command list. The commands in the list specify the slave device to be
addressed, the function to be performed (read or write), the data area in the
device to interface with and the registers in the internal database to be
associated with the device data. There is a separate command list for each
master port, with up to 100 commands allowed per master port. The command
list is processed from top (command #0) to bottom. A poll interval parameter is
associated with each command to specify a minimum delay time in seconds
between the issuance of a command. If the user specifies a value of 10 for the
parameter, the command will be executed no more frequently than every 10
seconds.
Write commands have a special feature, as they can be set to execute only if the
data in the write command changes. If the register data values in the command
have not changed since the command was last issued, the command will not be
executed. If the data in the command has changed since the command was last
issued, the command will be executed. Use of this feature can lighten the load on
the DF1 network. In order to implement this feature; set the enable code for the
command to a value of 2.
If the module is configured for the DF1 half-duplex protocol, the module can act
as a master device routing messages between attached slave devices. This
peer-to-peer communication is defined in the DF1 protocol specification. The
master polls each DF1 slave device until no more data is available from the
device. Response messages from the slaves that have a destination address that
do not match the module are routed with a request message header back out
onto the network. This facility offers communication between the slave devices
for control and data monitoring. This feature is not available if the module is
configured for DF1 full-duplex mode (point-to-point).
The module supports numerous commands. This permits the module to interface
with a wide variety of DF1 protocol devices. This includes PLC2, PLC5, SLC-500
series, MicroLogix and ControlLogix processors. Additionally, other devices
supplied by that use the DF1 protocol are supported.