ProSoft Technology MVI71-MCM - Manual (Page 75)

Reference MVI71-MCM ♦ PLC Platform
Modbus Communication Module
ProSoft Technology, Inc. Page 75 of 111
December 28, 2007
Offset Description Length
0 9956/9957 1
1 to 63 Spare 63
This will inform the module that the command has been processed and can be
cleared from the pass-through queue.
Function 15
When the module receives a function code 15 when in pass-through mode, the
module will write the data using block ID 9959 for multiple-bit data. First the bit
mask clears the bits to be updated. This is accomplished by ANDing the inverted
mask with the existing data. Next the new data ANDed with the mask is ORed
with the existing data. This protects the other bits in the INT registers from being
affected.
Offset Description Length
0 0 1
1 9959 1
2 Number of Words 1
3 Word Address 1
4 to 63 Data 60
The ladder logic will be responsible for parsing and copying the received
message and performing the proper control operation as expected by the master
device. The processor must then respond to the pass-through control block with
a write block with the following format.
Offset Description Length
0 9959 1
1 to 63 Spare 63
This will inform the module that the command has been processed and can be
cleared from the pass-through queue.
5.2.11 Remote Command Control
Command Control data is received from other nodes on the network that can
control the MVI71-MCM module. Specific values are written to regions of this
block to control the module. Currently, the module is programmed to handle the
receipt of the following requests: write configuration to processor, warm boot and
cold boot.
The remote node controls the module by writing one of the following values to
register 7800 (Modbus address 47801):
Value Description
9997 Write configuration in database to the processor and warm boot the
module.
9998 Warm boot the module.
9999 Cold boot the module.