Comtrol Modbus TCP User Guide User Manual
Page 48

48 - Chapter 3. Embedded Configuration Pages
DeviceMaster UP Modbus/TCP User Guide: 2000447 Rev. I
Serial Modbus Master and Modbus/TCP Settings
Maximum Rx Data
Packet Size
Specifies the maximum acceptable size of a received serial or Ethernet packet.
Default is 246 bytes. Maximums, Slave Receive mode = 246, Serial receive
master mode=1024, Ethernet receive master mode = 2048.
Oversize Rx Packet
Handling
Specifies how to process oversized received packets.
•
Truncate – truncate the packet to the Maximum Rx Data Packet Size.
•
Drop – drop the packet.
Default = Truncate
Rx MS Byte First
When you select this check box, the DeviceMaster UP receives the Most
Significant (MS) byte of a WORD first. This check box is clear by default. Clear
the check box when you need to receive the Least Significant (LS) byte of a
WORD first.
Tx MS Byte First
This check box is clear by default. When you select this check box,
DeviceMaster UP transmits the Most Significant (MS) byte of a WORD first.
Clear the check box when you need to transmit the Least Significant (LS) byte
of a WORD first.
Disable Non-Filtered To
PLC Rx Queue
If filtering is disabled, only the last message received is sent to the PLC.
This box is clear by default.
Disable Tx Sequence
Number Check
Controls the transmit sequence number checking.
•
If selected, the transmit sequence number checking is disabled. All
transmit messages will be transmitted if the sequence number has been
incremented or not.
•
If not selected, the sequence number is checked and the message will only
be transmitted if the sequence number has been updated.
Default is Not selected.
Serial Modbus Master and Modbus/TCP Settings (Continued)