Rockwell Automation RECOMM-ENET EtherNet/IP Communications Module - Manual (Page 150)

C-14 EtherNet/IP Communications Module
N-Files
N-File Description
N40 This N-file lets you use Emulated Block Transfer messages to read and write
many types of DPI messages. To use Emulated Block Transfer messages, you
send a Write message to N40:0 – N40:63, wait until the module responds with a
reply message, and then read the response data in N40:0 – N40:63 with a Read
message.
Bits 15 to 8 are the Most Significant Byte. Bits 7 to 0 are the Least Significant
Byte.
Write Read
Bits 15 0 15 0
N40:0 0x00 Length (in Bytes) 0x00 Length (in Bytes)
N40:1 DPI Port 0x81 Status Size Status Type
N40:2 0x00 CIP Services Data
(length varies based on message)
N40:3 CIP Class
N40:4 CIP Instance
N40:5 CIP Attribute
N40:6 Data
(length varies based on message)
…
N40:63
N41
This N-file lets you read and write control I/O messages. You can write control I/O
messages only when all of the following conditions are true:
• The module is not receiving I/O from a scanner. For example, there is no
scanner on the network, the scanner is in idle (program) mode, the scanner
is faulted, or the module is not mapped to the scanner.
• The module is not receiving Peer I/O from another module.
• The module is configured to receive I/O (for example, the DPI I/O Cfg
parameter).
• The value of N42:3 is set to a non-zero value.
Write Read