Step – Comtrol Modbus TCP Quick Start User Manual
Page 41
DeviceMaster UP Modbus/TCP Quick Start: 2000477 Rev. G
Configuring Read/Write Raw/ASCII Devices - 41
Configuring Read/Write Raw/ASCII Devices
h. Set the Disable Tx Sequence Number Check option if you want to disable 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 incremented.
i.
Go to Step
on Page 45 to complete configuration.
11. PLC Slave/DeviceMaster UP Master Mode Only:
Use the following procedure to configure PLC Slave/DeviceMaster UP Master mode.
Under the Serial Modbus Master and Modbus/TCP Settings (Raw-Data Only) section:
a.
Set Rx (To PLC) Transfer Mode to Master (Write to PLC).
b.
Set 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 1518 bytes in Master 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 during the Maximum PLC Update Rate time period, only
the last received data packet will be returned.).
Under the Modbus/TCP Master Rx/TX Settings (Raw-Data Only) section:
h. Enter the PLC IP Address:
•
For Modbus/TCP slaves, set the PLC IP Address to that of your PLC in xxx.xxx.xxx.xxx format.
•
For Modbus/RTU or Modbus/ASCII serial slaves, set the PLC IP Address to that of this
DeviceMaster UP in xxx.xxx.xxx.xxx format.
Note: The Modbus serial slave must be attached to one of the serial ports on this DeviceMaster UP
chassis.