Omega A2400 manual Command $1RS Response *31070000, Command $1WE Response Command $1SU31020000

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: *