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ProSoft Technology MVI69E-MBS User Manual

Page 55

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MVI69E-MBS ♦ CompactLogix Platform

MVI69E-MBS Configuration

Communication Module

User Manual

ProSoft Technology, Inc.

Page 55 of 162

January 6, 2014

Data Bits

7 or 8

Sets the number of data bits for each word used by the
protocol. All devices communicating through this port must
use the same number of data bits.

Stop Bits

1 or 2

Sets the number of stop bits that signal the end of a character
in the data stream. For most applications, use one stop bit.
For slower devices that require more time to re-synchronize,
use two stop bits. All devices communicating through this port
must use the same number of stop bits.

RTS On

0 to 65535
milliseconds

Sets the number of milliseconds to delay after Ready To
Send
(RTS) is asserted before data is transmitted.

RTS Off

0 to 65535
milliseconds

Sets the number of milliseconds to delay after the last byte of
data is sent before the RTS modem signal is set low.

Use CTS Line

Yes or No

Specifies if the Clear To Send (CTS) modem control line is to
be used or not. If the parameter is set to N

O

, the CTS line is

not monitored. If the parameter is set to Y

ES

, the CTS line is

monitored and must be high before the module sends data.
Normally, this parameter is required when half-duplex
modems are used for communication (2-wire). This procedure
is commonly referred to as hardware handshaking.

Float Flag

Yes or No

Specifies how the Slave driver responds 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.

Note: Most applications using floating-point data do not need
this parameter enabled.

If the remote Master expects to receive or sends 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 returns 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 sends 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 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

Defines the first register of floating-point data. All requests
with register values greater-than or equal to this value is
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
is considered as floating-point data.

Float Offset

0 to 9999

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 uses the internal Modbus register 3000.