ProSoft Technology MVI69-MCM - Manual (Page 133)

MVI69-MCM ♦ CompactLogix or MicroLogix Platform Reference
Modbus Communication Module User Manual
ProSoft Technology, Inc. Page 133 of 167
March 22, 2011
5.5.6 Initialize Output Data
When the module performs a restart operation, it will request blocks of output
data from the processor to initialize the module’s output data. Use the I
NITIALIZE
O UTPUT D ATA parameter in the configuration file to bring the module to a known
state after a restart operation. The following table describes the structure of the
request block.
Offset Description Length
0 4000 to 4083 for n = 60 1
1 4000 to 4083 for n = 60 1
2 to n Spare n
n=60, 120, or 240 depending on the Block Transfer Size parameter (refer to the configuration file).
Ladder logic in the processor must recognize these blocks and place the correct
information in the output image to be returned to the module. The format of the
returned write block is shown in the following table.
Offset Description Length
0 4000 to 4083 1
1 to n Output Data n
5.5.7 Warm Boot Block (9998)
This block is sent from the CompactLogix or MicroLogix processor to the module
(output image) when the module is required to perform a warm-boot (software
reset) operation. The following table describes the format of the control block.
Offset Description Length (words)
0 9998 1
1 to n Spare 247
n=60, 120, or 240 depending on the Block Transfer Size parameter (refer to the configuration file).
5.5.8 Cold Boot Block (9999)
This block is sent from the CompactLogix or MicroLogix processor to the module
(output image) when the module is required to perform the cold boot (hardware
reset) operation. This block is sent to the module when a hardware problem is
detected by the ladder logic that requires a hardware reset. The following table
describes the format of the control block.
Offset Description Length (words)
0 9999 1
1 to n Spare 247
n=60, 120, or 240 depending on the Block Transfer Size parameter (refer to the configuration file).