ProSoft Technology MVI71-MCM - Manual (Page 91)

Reference MVI71-MCM ♦ PLC Platform
Modbus Communication Module
ProSoft Technology, Inc. Page 91 of 111
December 28, 2007
Write
Block
Offset Internal
Database
Register Content Description
40 5048 Data Bits This parameter sets the number of data bits for each word
used by the protocol. Valid entries for this field are 5
through 8.
41 5049 Stop Bits This parameter sets the number of stop bits to be used with
each data value sent. Valid entries are 1 and 2.
42 5050 RTS On This parameter sets the number of milliseconds to delay
after RTS is asserted before the data will be transmitted.
Valid values are in the range of 0 to 65535 milliseconds.
43 5051 RTS Off This parameter sets the number of milliseconds to delay
after the last byte of data is sent before the RTS modem
signal will be set low. Valid values are in the range of 0 to
65535.
44 5052 Minimum
Response
Time
This parameter specifies the minimum number of
milliseconds to delay before responding to a request
message. This pre-send delay is applied before the RTS on
time. This may be required when communicating with slow
devices.
45 5053 Use CTS
Line
This parameter specifies if the CTS modem control line is to
be used. If the parameter is set to 0, the CTS line will not be
monitored. If the parameter is set to 1, the CTS line will be
monitored and must be high before the module will send
data. This parameter is normally only required when half-
duplex modems are used for communication (2-wire).
46 5054 Slave ID This parameter defines the virtual Modbus slave address for
the internal database. All requests received by the port with
this address are processed by the module. Verify that each
device has a unique address on a network. Valid range for
this parameter is 1 to 255 (247 on some networks).
47 5055 Bit Input
Offset
This parameter specifies the offset word address in the
internal Modbus database that is to be used with network
requests for Modbus Function 2 commands. For example, if
the value is set to 150, an address request of 0 will return
the value at the first bit in register 150 in the database.
48 5056 Word
Input
Offset
This parameter specifies the offset address in the internal
Modbus database that is to be used with network request
for Modbus function 4 commands. For example, if the value
is set to 150, an address request of 0 will return the value at
register 150 in the database.
49 5057 Bit Output
Offset
This parameter specifies the offset word address in the
internal Modbus database that is to be used with network
requests for Modbus function 1,5, or 15 commands. For
example, if the value is set to 100, an address request of 0
will correspond to the first bit at register 100 in the
database.
50 5058 Holding
Reg Offset
This parameter specifies the offset address in the internal
Modbus database that is to be used with network requests
for Modbus function 3, 6, or 16 commands. For example, if
a value of 50 is entered, a request for address 0 will
correspond to the register 50 in the database.
51 5059 Command
Count
This parameter specifies the number of commands to be
processed by the Modbus master port.