Ronan X11CA - Manual (Page 9)

Rev 2.0 : X11CA-IM MASTER MODULE
7
4.4 Modbus RTU Protocol Function 5: Force Single Cells
To send alarms to X11CA-IM serially, use Modbus RTU Protocol function 5.
Function 5 allows you to set a single window either to ON or OFF.
Query
The query message specifies the windows reference to be forced. Windows are
addressed starting at zero. The first window is addressed as 0.
The requested ON/OFF state is specified by a constant in the query data field.
A value of FF 00 hex requests the window to be ON. A value of 00 00
requests it to be OFF. All other values are illegal and will not affect the
window.
EXAMPLE:
The following example sets the window 173 ON in the slave device 17
(X11CA-IM).
11
HEX
= 10001
BIN
=17
DEC
AC
HEX
=10101100
BIN
=172
DEC
Field Name Example (Hex)
Slave Address 11
Function 05
Window Address Hi 00
Window Address L AC
Force Data Hi FF
Force Data Lo 00
Error Check (LRC or CRC) --
Table 4-4 Modbus Function 5 Example-Query
Response
The normal response is an echo of the query, returned after the window state has
been forced.
EXAMPLE:
The following example is a response to the query.