Filter
Top Products
53
6. Configuring the Gateway
6.8. Changing the Periodic Data Exchanged with a Modbus Slave
This operation consists of replacing, adding or deleting periodic data exchanged with one of the Modbus slaves.
With each of these operations, we shall take the default configuration of the LUFP7 gateway as an example, that
is to say that any changes previously made will have been cancelled at the start of each operation. In addition,
the operations to be carried out are shown as part of a targeted example.
You must never forget to save the changes you have made, or to transfer the whole configuration to the
gateway. This will allow you to check that the configuration is valid.
6.8.1. Replacing a periodic input data element
E.g.
“TeSys U n°3” motor starter. We are trying to replace the monitoring of the “TeSys U Status Register”
(address 455 = 16#01C7) with the monitoring of the “1st Fault Register” (address 452 = 16#01C4).
The operation is a very simple one and consists purely of changing the value of the “Starting Address (Hi, Lo)”
element of the “Query” from the “Read Holding Registers” command (Modbus command for reading the values
of a number of registers).
Select this element, then change its value as shown below. You can enter the address of the parameter in
decimal format. AbcConf will automatically convert it to hexadecimal.
This operation in no way changes the content of the gateway’s memory, because we do not need to change the
values of the “Data length” and “Data location” fields of the “Data” element of the “Response” to the
aforementioned command. So no additional operations will be necessary, either in AbcConf, or in SyCon.
On the other hand, the Profibus-DP master PLC software will have to take account of the change in the nature of
the corresponding input. In the chapter 10.2.1 Input Data Memory Area, page 95, the description of the word
located at address 16#0006 becomes “value of the motor starter
e 1st default register”. This word corresponds
to the PLC input word %IW4.0.3 (see chapter 4.2.9 Configuring the Gateway I/O under PL7 PRO, page 32).