Comtrol UP DeviceMaster Quick Start - Manual (Page 12)

12 - Configuring Read-Only Serial Devices DeviceMaster UP EtherNet/IP Quick Start: 2000478 Rev. D
Configuring Read-Only Serial Devices
The format of data sent to ControlLogix family PLCs:
For large received data packets over 440 bytes in size:
• Data larger than 440 SINTs require a series of tags of 444 SINT in size.
• The last tag can be smaller in size as long as the total length of all tags in the sequence is sufficient to
hold the largest receive packet, plus four bytes for the sequence number and length parameters.
• Each tag must be named in sequence with the second tag having a 2 appended, the third having a 3
appended and so on. An example series of tags to hold large packets of received data would be:
Com1_RxData, Com1_RxData2, Com1_RxData3, etc.
• All data will have been transferred to the PLC when the sequence number is updated.
The format of data sent to SLC/PLC-5 PLCs:
For large received data packets:
• The data is automatically placed in sequential files.
• The files must be 256 integers in size with the exception of the last file. The last file may be shorter than
256 integers as long as the total length of all files in the sequence is sufficient to hold the largest receive
packet, plus two integers for the sequence number and length parameters.
• All data is transferred to the PLC when the sequence number is updated.
Name Data Type Data Value(s)
Receive (DeviceMaster to PLC message data.
Structure of:
Produced data sequence
Data length (in bytes)
Data array
UINT
UINT
Array of USINT
0-65535 (FFFF Hex)
0-1024
0-255
Name Data Type Data Value(s)
Receive (DeviceMaster to PLC message data.
Structure of:
Produced data sequence
Data length (in bytes)
Data array
UINT
UINT
Array of UINT
0-65535 (FFFF Hex)
0-1024
0-65535