Rockwell Automation RECOMM-485 RS485 DFI Communications Module - Manual (Page 25)

Configuring the RS485 DF1 Module 4-3
4.4 Setting the Data Rate
If the Data Rate switch on the module is set to “PGM,” the value of
module parameter 5 (DF1 Rate Cfg) determines the RS485 DF1
data rate. Your application may require a different setting.
Step 1. Set the value of module parameter 5 (DF1 Rate Cfg) to
the data rate at which your network is operating. Refer to
figure 4.3.
Step 2. Reset the module. Refer to section 4.7.2, Resetting the
Module.
4.5 Setting the Error-Checking Method
Two types of error-checking methods are used with the DF1
protocol: Cyclic Redundancy Check (CRC) and Block Check
Character (BCC). (Refer to the Glossary for a description of each
method.)
Step 1. Set the value of module parameter 24 (CRC/BCC) to the
method used by the network as shown in figure 4.4.
Step 2. Reset the module. Refer to section 4.7.2, Resetting the
Module.
Figure 4.3 – Data Rate Screen on an LCD OIM
Port 5 Device
RECOMM-485
Parameter #: 5
DF1 Rate Cfg
3
9600 bps
Value Baud Rate
0 1200 bps
1 2400 bps
2 4800 bps
3 9600 bps (default)
4 19.2 kbps
5 38.4 kbps
Figure 4.4 – Error-Checking Method Screen on an LCD OIM
Port 5 Device
RECOMM-485
Parameter #: 24
CRC/CBC
0
BCC
Value Selection
0 BCC (default)
1 CRC