Comtrol Modbus TCP Quick Start - Manual (Page 46)

46 - Configuring Read/Write Raw/ASCII Devices DeviceMaster UP Modbus/TCP Quick Start: 2000477 Rev. G
Configuring Read/Write Raw/ASCII Devices
15. 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 is not selected.
• If an application socket interface is required, see Application Socket Configuration on Page 67.
16. Scroll to the bottom of the page, verify that Reset Port and Save in Flash are selected, and click Submit.
Modbus Addressing
The DeviceMaster UP serial port data addressing used for slave modes:
Receive and Transmit Message Formats
The format of received serial data messages sent to or returned from the PLC:
General requirements:
• The memory area must be defined in 16 bit words and large enough to handle the largest serial packet
plus two words for the produced sequence number and data length parameters.
• The Maximum Rx Data Packet Size must be set large enough to accept the largest possible packet.
For large received data packets over 246 bytes (This may be less for your PLC):
• The Rx (To PLC) Transfer Mode must be set to Master (Write to PLC).
• The data will automatically be placed in continuous memory.
• All data will have been transferred to the PLC when the sequence number is updated.
The format of the transmit serial data received from the PLC:
Serial Port Raw/
ASCII Addressing
Serial Port 1 Serial Port 2 Serial Port 3 Serial Port 4 Access Rule
Unit ID 255 (FF Hex) 255 (FF Hex) 255 (FF Hex) 255 (FF Hex) N/A
Receive Data Address
1000 (Base 0)
1001 (Base 1) 2000 (Base 0)
2001 (Base 1) 3000 (Base 0)
3001 (Base 1) 4000 (Base 0)
4001 (Base 1)
Read Only
Transmit Data
Address 1300 (Base 0)
1301 (Base 1) 2300 (Base 0)
2301 (Base 1) 3300 (Base 0)
3301 (Base 1) 4300 (Base 0)
4301 (Base 1)
Read/Write
Name Data Type Data Value(s) Access Rule
Receive (DeviceMaster UP to PLC)
message data.
Structure of:
Produced data sequence
Data length (in bytes)
Data array
WORD
WORD
Array of
WORD
0-65535 (FFFF Hex)
1-1024 (Master Rx Mode)
0-246 (Slave Rx Mode)
0-65535
Read
Name Data Type Data Value(s) Access Rule
Transmit (PLC to DeviceMaster UP)
message data.
Structure of:
Produced data sequence
Data length (in bytes)
Data array
WORD
WORD
Array of
WORD
0-65535 (FFFF Hex)
1-236 (Slave Mode)
1-246 (Master Mode)
0-65535
Read/Write