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Page 44
44 - Configuring Read/Write Raw/ASCII Devices
DeviceMaster UP Modbus/TCP Quick Start: 2000477 Rev. G
Configuring Read/Write Raw/ASCII Devices
m. Set the Use Maximum Sized Modbus Messages option if you are receiving messages over 196 bytes, your
PLC can receive messages larger than 200 bytes, and you want to decrease latency and network
usage.
Note: Go to Step
on Page 45 to complete configuration.
13. Dual Master – Read Mode Only:
Use the following procedure to configure Dual Master – Read mode.
Under the Serial Modbus Master and Modbus/TCP Settings (Raw-Data Only) section:
a.
Set the Rx (To PLC) Transfer Mode to Slave (PLC Polls).
b.
Set the Tx (From PLC) Transfer Mode to Master (Poll the PLC).
c.
Set the Maximum Rx Data Packet Size to that of the largest expected receive data packet. This can be a
maximum of 246 bytes in Slave Rx Mode.
d.
Set the Oversized Rx Packet Handling to either Truncate or Drop, depending how you want to handle
oversized received packets.
e.
Set Rx MS Byte First if you want to receive data most significant byte first.
f.
Set Tx MS Byte First if you want to transmit data most significant byte first.
g.
Set the Disable Non-Filtered To PLC Rx Queue option if you only want to receive the last received data
packet. (If two or more packets are received between received data requests, only the last received
data packet will be returned.)