ProSoft Technology 5204SE-MNET-PDPMV1 - Manual (Page 107)

Reference 5204SE-MNET-PDPMV1 ♦ ProLinx Gateway
User Manual Modbus TCP/IP to PROFIBUS DP-V1 Pass-Through Master
ProSoft Technology, Inc.
Page 107 of 235
December 22, 2009
MNETDPV1_Outputs Variable - M340
This variable is an array of 1536 bytes. It is used to hold up to 768 words (1536
bytes) of PROFIBUS cyclic output data to be sent to slaves on the PROFIBUS
network.
The order of data in this array will match the order in the PCB memory maps you
exported and/or printed. The following illustration shows a typical memory map.
The PCB table lists usage in words rather than bytes, where one (1) word equals
two (2) bytes. In this example, there are only 32 total words or 64 total bytes of
PROFIBUS output data configured of the 1536 bytes available that could be
used. The first 64 bytes (32 words) this array will hold data to be sent to Slave
Address 1, Slot 0.
You should also notice that the native storage size in the module's memory is 16-
bit or 2-byte word registers. When you have more than one slave device, this
data is 'byte-packed' with no extra blank bytes inserted just so the data for each
slave address can begin on an even-numbered, low-order byte boundary.