Omron DDAA1000/SRM manual Main Menu Option 1 Set Baud Rate, ModBus RTU

DDAA1000/SRM User Guide

Main Menu Option (1): Set Baud Rate

When option (1) is selected you will be able to change the radio modem’s RS-232 baud rate. This is the communication rate between the radio modem and the instrument to which it is connected. It is important to note that this is independent of the baud rate for the other radio modem(s) in the communication loop. For example, DDAA1000/SRMs may be used in an application to send data from remote process instrumentation to an engineer’s computer. In this application, the baud rate for the radio modem on the instrumentation might be set to 9600, and the radio modem on the computer might be set to 57,600 or 115,200.

In general, it is desirable to set the baud rate to the highest level supported by the device to which it is connected. However, please note that this may actually result in slower data communications if the UART chipset of the connected device does not support higher data rates.

The DDAA/DD1000 use 8 Data Bits/ no Parity, 1 Stop bit only. Do not change. These settings are not used when setting radio operating values. The default setting is 0 (8,N,1).

Table 3: Available data word length and parity selections

Menu	Data Bits	Parity	Stop Bits
Setting
0	8	None	1
1	7	Even	1
2	7	Odd	1
3	8	None	2
4	8	Even	1
5	8	Odd	1

Note: The RF parameter baud rate must match the internal set baud rate in the EEprom. A mismatched baud rate will cause communication to alway stop.

ModBus RTU

Do not use this mode with the DDAA1000/DD1000.

PN 161-09981-002C

rev 8/04

DATA-LINC GROUP 25