ProSoft Technology MVI46-MCM - Manual (Page 30)

Ladder Logic MVI46-MCM ♦ SLC Platform
User Manual Modbus Communication Module
Page 30 of 108 ProSoft Technology, Inc.
March 29, 2011
3.1.5 User Data
All user data is stored in the module’s M1 file in registers 0 to 4999. This 5000-
word area is directly accessible from the ladder logic. The COP instruction should
be used to move blocks of data between the user data files and the module’s M1
file. This limits the number of accesses to the M1 data area and provides faster
system response. In the example ladder logic, N31 holds data read from the
module, and N32 stores data to write to the module.
3.1.6 Slave Polling Control and Status
Two data areas can be allocated in the SLC to hold the polling status of each
slave on the master ports. This status data can be used to determine which
slaves are currently active on the port, are in communications error, or have their
polling suspended and disabled. If the configuration supplies an address where
this data resides, copy the data from the M1 file to the reserved files in the SLC.
Using special blocks, the processor can enable or disable the polling of selected
slaves.