ProSoft Technology MVI46-DFCM - Manual (Page 61)

Reference MVI46-DFCM ♦ SLC Platform
DF1 Communication Module
ProSoft Technology, Inc. Page 61 of 103
October 20, 2008
Command Control Block
Command control blocks place commands in the command list into the
command queue. Each port has a command queue of up to 100 commands. This
module services commands in the queue before the master command list. This
gives high priority to commands in the queue. Commands placed in the queue
through this mechanism must be defined in the master command list. Under
normal command list execution, the module will only execute commands with the
Enable parameter set to one or two. If the value is set to zero, the command is
skipped. Commands may be placed in the command list with an Enable
parameter set to zero. These commands can then be executed using the
command control blocks. One to six commands can be placed in the command
queue with a single request. The format of the block is shown in the following
table.
Event Command
Event command control blocks send DF1 commands directly from the ladder
logic to one of the master ports. The format for these blocks is displayed below:
M1 Offset Description Length
7800 1000 or 2000 1
7801 Internal DB Address 1
7802 Point Count 1
7803 Swap Code 1
7804 Node Address 1
7805 Function Code 1
7806 Parameter #1 1
7807 Parameter #2 1
7808 Parameter #3 1
7809 Parameter #4 1
The block number defines the DF1 port to be considered. Block 1000 commands
are directed to Port 1, and block 2000 commands are directed to Port 2. The
parameters passed with the block construct the command. The Internal DB
Address
parameter specifies the module's database location to associate with
the command. The Point Count parameter defines the number of registers for
the command. The Swap Code changes the word or byte order. The Node
Address
parameter defines the device on the DF1 network to consider. The
Function Code parameter is one of those defined in the ProSoft DF1 Command
Set documentation. The parameter fields in the block should be completed as
required by the selected function code. Each command has its own set of
parameters. When the block is received, the module will process it and place the
command in the command queue. The module will respond to each event
command block with a read block with the following format:
M0 Offset Description Length
0 1000 or 2000 1
1 0=Fail, 1=Success 1