Varec 8300 series, Installation And Operation Manual, Page: 79 / 150

8303
Varec, Inc. 69
5.8 Modbus Floating Point Register (MFPREG)
The Modbus Floating Point Register point provides an interface to Modbus
compatible slave devices. When used with an MSCAN point, the MFPREG connects to
up to four blocks of floating point data, allowing access to a total of 64 register
values.
5.8.1 Parameters
The database parameters used by the MFPREG point are listed and described below:
Configuration Parameters Function
Tag A Tag can contain 15 bytes of data and can include any printable ASCII
character. Tags can be used to identify points indicating the use of the
point such as “Modbus Slave” or “Register Value1.” The default tag is set
to “MFPREG.00”
Chan Physical channel number the slave device is connected to. On the 8203
Dual RS-485 Communications Interface Module, the Chan can be set to
1 or 2. On the 8303 TGI motherboard, the Chan can be set to 0, 1 or 2.
BaudRate Baud Rate for communications to the Slave device. Valid values are:
1200, 2400, 2400, 9600 and 19200. The BaudRate is set prior to
scanning the device
ComParams Defines the number of data bits and the parity used by the com port.
Valid values include:
8N - 8 data bits, No parity
8O - 8 data bits, Odd parity
8E - 8 data bits, Even parity
7O - 7 data bits, Odd parity
7E - 7 data bits, Even parity
The default is ‘8N’.
ID Slave Address of the device to be scanned.
Mode HEX byte value for the Operational Mode: 0x01 – Swap mode
ReadCmd Command to use to Read data from the slave device
WriteCmd Command to use to Write data to the slave device
Data Address and Block Size
pairs.
The MFPREG point will read data from the slave device, starting at Addr1
and request Size1 registers. Up to four blocks may be defined. If the
Size is zero, then no read operation is performed. The data is returned
to the Value array.
Addr1, Size1
Addr2, Size2
Addr3, Size3
Addr4, Size4
Report Causes automatic notification to the Host (in response to a Change of
State Request) when the Value Changes State. Parameter value can be
High, Low or No. No disables notification. Points with Report = High will
be sent before points with Report = Low. The default is High.
Maxtime Specifies the maximum time (in secs) between automatic Change of
State data being sent to the Host in response to a Change of State
Request. Report must be set to either Low or High for the Value
parameter to be sent in response to a Change of State Request. A value
of 0 disables this option. Non-zero values cause responses to be sent
even if the value has not changed since the last message. The maximum
is 65535 seconds. The default is 600.