ProSoft Technology MVI69-MCM - Manual (Page 109)

MVI69-MCM ♦ CompactLogix or MicroLogix Platform Reference
Modbus Communication Module User Manual
ProSoft Technology, Inc. Page 109 of 167
March 22, 2011
Data contained in this database is paged through the input and output images by
coordination of the CompactLogix or MicroLogix ladder logic and the MVI69-
MCM module's program. Up to 242 words of data can be transferred from the
module to the processor at a time. Up to 241 words of data can be transferred
from the processor to the module. The read and write block identification codes
in each data block determine the function to be performed or the content of the
data block. The block identification codes used by the module are listed below:
Block Range Descriptions
-1 Status Block
0 Status Block
1 to 84 Read or write data
1000 Event Port 1
2000 Event Port 2
3000 to 3001 Port 1 slave polling control
3002 to 3006 Port 1 slave status
3100 to 3101 Port 2 slave polling control
3102 to 3106 Port 2 slave status
5000 to 5006 Port 1 command control
5100 to 5106 Port 2 command control
9958 Function Code 5 data formatted Pass-Thru Control Blocks
9956 and 9957 Function Code 6 and 16 (Floating-point) data formatted Pass-Thru Control
Block
9959 Function Code 15 data formatted Pass-Thru Control Block
9998 Warm-boot control block
9999 Cold-boot control block
Each image has a defined structure depending on the data content and the
function of the data transfer.