ProSoft Technology MVI69-MCM - Manual (Page 54)

Configuring the MVI69-MCM Module MVI69-MCM ♦ CompactLogix or MicroLogix Platform
User Manual Modbus Communication Module
Page 54 of 167 ProSoft Technology, Inc.
March 22, 2011
Float Flag
Y
ES
or N
O
This flag specifies how the Slave driver will respond to Function Code 3, 6, and
16 commands (read and write Holding Registers) from a remote Master when it
is moving 32-bit floating-point data.
If the remote Master expects to receive or will send one complete 32-bit floating-
point value for each count of one (1), then set this parameter to Y
ES
. When set to
Y ES
, the Slave driver will return values from two consecutive 16-bit internal
memory registers (32 total bits) for each count in the read command, or receive
32-bits per count from the Master for write commands. Example: Count = 10,
Slave driver will send 20 16-bit registers for 10 total 32-bit floating-point values.
If, however, the remote Master sends a count of two (2) for each 32-bit floating-
point value it expects to receive or send, or, if you do not plan to use floating-
point data in your application, then set this parameter to N
O
, which is the default
setting.
You will also need to set the Float Start and Float Offset parameters to
appropriate values whenever the Float Flag parameter is set to Y
ES
.
Float Start
0 to 32767
This parameter defines the first register of floating-point data. All requests with
register values greater-than or equal to this value will be considered floating-point
data requests. This parameter is only used if the Float Flag is enabled. For
example, if a value of 7000 is entered, all requests for registers 7000 and above
will be considered as floating-point data.
Float Offset
0 to 4999
This parameter defines the start register for floating-point data in the internal
database. This parameter is used only if the Float Flag is enabled. For example,
if the Float Offset value is set to 3000 and the float start parameter is set to 7000,
data requests for register 7000 will use the internal Modbus register 3000.
Protocol
RTU or ASCII
This parameter specifies the Modbus protocol to be used on the port. Valid
protocols are: rtu = Modbus RTU and ascii = Modbus ASCII.