Omega A2400 - Manual (Page 44)

SetUp Command 5-5
changed, a module reset must occur. A reset is performed by sending a
Remote Reset (RR) command or powering down. This extra level of write
protection is necessary to ensure that communications to the module is not
accidentally lost. This is very important when changing the baud rate of an
RS-232C string. For more information on changing baud rate, refer to
Chapter 3.
Let’s run through an example of changing the baud rate. Assume our sample
module contains the setup data value of ‘31070000’. Byte 2 is ‘07’. By
referring to the SU command chart we can determine that the module is set
for no linefeeds, no parity, and baud rate 300. If we perform the Read Setup
command with this module we would get:
Command: $1RS
Response: *31070000
Let’s say we wish to change the baud rate to 9600 baud. The code for 9600
baud is ‘0010’ (from Table 5.2). This would change byte 2 to ‘02’. To perform
the SU command we must first send a Write Enable command because SU
is write protected:
Command: $1WE
Response: *
Command: $1SU31020000
Response: *
This sequence of messages is done in 300 baud because that was the
original baud rate of the module. The module remains in 300 baud after this
sequence. We can use the Read Setup (RS) command to check the setup
data:
Command: $1RS
Response: *31020102
Notice that although the module is communicating in 300 baud, the setup
data indicates a baud rate of 9600 (byte 2 = ‘02’). To actually change the
baud rate to 9600, send a Remote Reset (RR) command (RR is write
protected):
Command: $1WE
Response: *