Comtrol Modbus TCP Quick Start - Manual (Page 24)

24 - Configuring Read-Only Raw/ASCII Devices DeviceMaster UP Modbus/TCP Quick Start: 2000477 Rev. G
Configuring Read-Only Raw/ASCII Devices
k. 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 12 on Page 24 to complete configuration.
11. Slave Receive Transfer Mode Only:
Use the following procedure to configure Slave Receive Transfer mode.
Under Serial Modbus Master and Modbus/TCP Settings (Raw-Data Only):
a. Set Rx (To PLC) Transfer Mode to Slave (PLC Polls).
b. Set Tx (From PLC) Transfer Mode to either Slave (PLC Writes) or Off.
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 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.)
12. Set up the filtering/data extraction settings:
• If no filtering/data extraction is required, leave all filtering/data extraction settings to defaults (off).
• If filtering/data extraction is required, see Filtering/Data Extraction Configuration on Page 61.
13. Set up the application socket interface settings:
• If no application socket interface is required, leave all application socket interface settings at defaults
and the application Enable option in not selected.
• If an application socket interface is required, see Application Socket Configuration on Page 67.
14. Scroll to the bottom of the page, verify that Reset Port and Save in Flash are selected, and click Submit.