Allen-Bradley 5069-SERIAL, User Manual, Page: 41 / 110

Rockwell Automation Publication 5069-UM003A-EN-P - May 2018 41
Compact 5000 I/O Serial Module Features Chapter 3
Modbus Master Functions
In Modbus mode, the serial module supports both Modbus ASCII and
Modbus RTU to connect to Modbus enabled devices like flowmeters, power
meters or remote RTU talking on Modbus RTU/ASCII.
Table 7 - Modbus Master Configuration Parameters
Parameter Definition Available Options
Modbus Format Selecting communication method of Modbus of each
channel. • 0 = RTU (default)
• 1 = ASCII
– Intervals of up to one second may elapse between
characters within the message. Unless the user has
configured a longer timeout, an interval greater
than 1 second means an error has occurred.
Response Timeout The Maximum Delay time of each channel until it receives
a response for Modbus Master Command from Modbus
Slave.
When the maximum time has passed, the Modbus
Master determines the Modbus Slave did not respond. • 0…3600000 (x1 ms)
(default = 200)
Broadcast Pause The Wait time of each channel until the Modbus Slave
finishes processing according to broadcasted command
from the Modbus Master.
The Modbus Master does not send the next command
until this time has passed. • 0…3600000 (x1 ms)
(default = 200)
Inter-frame Timeout Maximum delay time to receive Data of each channel • 0 is not a valid value. Use Table 8 and Table 9 to
determine the minimum value.
Retry Count This parameter specifies the number of times a command
is retried if it fails. If the Master Port does not receive a
response after the last retry, the Slave devices
communication is suspended on the port for Error Delay
Counter scans. • 0…127
(default = 0)
Table 8 - Inter-frame Timeout Minimum Values (10 Bit)
Baud Rate Default Value 1Byte (10Bit) 3.5t (10Bit) Legal Range (10Bit)
1200 58000 8333.333 29166.667 29000…65535000 (us)
2400 28000 4166.667 14583.333 14000…65535000 (us)
4800 14400 2083.333 7291.667 7200…65535000 (us)
9600 7200 1041.667 3645.833 3600…65535000 (us)
19200 3500 520.833 1822.917 1750…65535000 (us)
38400 3500 260.417 911.458 1750…65535000 (us)
57600 3500 173.611 607.639 1750…65535000 (us)
115200 3500 86.806 303.819 1750…65535000 (us)