ProSoft Technology MVI69L-MBTCP - Manual (Page 122)

Reference MVI69L-MBTCP ♦ CompactLogix Platform
User Manual Communication Module
Page 122 of 152 ProSoft Technology, Inc.
January 6, 2014
Specific Example #1: Client is issuing Modbus command with FC 16 (with Float Flag: Yes) to
transfer Float data to Server.
(Float specific module parameters)
Float Flag: "Y" tells the Client to consider the data values that need to be sent to
the Server as floating-point data where each data value is composed of 2 words
(4 bytes or 32 bits).
Float Start: Tells the Client that if this address number is <= the address number
in "Addr in Dev" parameter to double the byte count quantity to be included in the
Command FC6 or FC16 to be issued to the Server. Otherwise the Client will
ignore the "Float Flag: Y" and treat data as composed of 1 word, 2 bytes.
(Modbus Command parameters)
DB Addr - Tells the Client where in its database is the beginning of data to
obtain and write out to the Server device.
Reg Count - Tells the Client how many data points to send to the Server. Two
counts will mean two floating points with Float Flag: Y and the "Addr in Dev" =>
the "Float Start" Parameter.
Swap Code - Tells the Client how to orient the Byte and Word structure of the
data value. This is device dependent. Check Command Entry formats Section.
Func Code - Tells the Client to write the float values to the Server. FC16.