6. Configuring the Gateway
Configuration | Description | |
element | ||
| ||
Trigger byte | The | |
address | slave by comparing the previous value and the current value of the associated counter | |
(contd.) | (address 16#001E or 16#001F). If there is a unitary incrementation of this counter, the PLC | |
| may, for example, read all of the data from the response (addresses 16#0013 to 16#0017 | |
| or addresses 16#0018 to 16#001D) and allow the transmission of a new query for reading | |
| or writing the value of a parameter (using a “Trigger byte” for the queries). Contrarily to the | |
| counter one can associate to the queries of any command, a response’s “Trigger byte” is a | |
| true modulo 256 counter, i.e. zero must be managed (… 254, 255, 0, 1, 2 …). |
E.g.: With the ATS48, we do not want the response to be event driven. So we will be retaining the default configuration.
6.11.2.4. Configuring the Content of the Query Frame
The window shown below is obtained using “Edit Frame” from the “Query” menu. Unlike the tree structure in the main AbcConf window, this display has the advantage of showing all of the frame’s fields at the same time as well as their values. The values displayed below correspond to the values assigned by default to the Modbus command query we have created. The correspondence with the content of the corresponding Modbus frame has been added underneath this window.
Slave no.
Function no.
Word number (MSB / LSB)
Value of the word (MSB / LSB)
CRC16 (LSB / MSB)
Edit the values which are not greyed out, one after another. There is a description of them below.
The nature of a frame’s fields depends on the Modbus command to which it corresponds. However, a certain number of these fields are common to all frames, whereas others are common to a number of them. The description of those shown above is given on the next page, as a part of the example described at the beginning of the chapter 6.11.2.
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