ProSoft Technology MVI56-DFCM - Manual (Page 85)

MVI56-DFCM ♦ ControlLogix Platform Reference
DF1 Half/Full Duplex Master/Slave Serial Communication Module User Manual
ProSoft Technology, Inc. Page 85 of 106
September 24, 2014
Offset Description Length
7 Parameter #2 1
8 Parameter #3 1
9 Parameter #4 1
10 to 247 Spare 242
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. Use the
parameters passed with the block to construct the command. The
I NTERNAL DB
A DDRESS parame ter specifies the module’s database location to associate with
the command. The P OINT C OUNT parameter defines the number of registers for
the command. The S WAP C ODE changes the word or byte order. The N ODE
A DDRESS parameter defines the device on the DF1 network to consider. The
F UNCTION C ODE parameter is one of those defined in the (page 91).
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 command block with a Read
Bock. The following table describes the format of this block.
Offset Description Length
0 Reserved 1
1 Write Block ID 1
2 0=Fail, 1=Success 1
3 to 248 Spare 246
249 1000 or 2000 1
Word Two (2) of the block can be used by the ladder logic to determine whether
or not the command was successfully added to the module's command queue.
The Event Command attempt will fail if the command queue for the port is full
(100 commands for each queue) or the command requested is invalid.
5.2.6 Slave Status Blocks (3002, 3003, 3102, and 3103)
Slave status blocks send status information of each slave device on a Master
port. Slaves attached to the Master port can have one of the following states:
Status Value Description
0 The slave is inactive and not defined in the command list for the Master port.
1 The slave is actively being polled or controlled by the Master port and
communications is successful.
2 The Master port has failed to communicate with the slave device.
Communications with the slave is suspended for a user defined period based
on the scanning of the command list.
3 Communications with the slave has been disabled by the ladder logic. No
communication will occur with the slave until this state is cleared by the ladder
logic.