Rockwell Automation 22-COMM-D DeviceNet Adapter - Manual (Page 62)

6-6 Using Explicit Messaging
PLC / SLC Explicit Message Responses
Refer to Page 6-5 for a description of the words in a PLC/SLC Explicit
Message request.
Word Description
0 Status (Least Significant Byte)
One of the following status codes is provided during each upload:
00 = Ignore transaction block (empty)
01 = Transaction completed successfully
02 = Transaction in progress (not ready)
03 = Slave not in scan list
04 = Slave offline
05 = DeviceNet port disabled or offline
06 = Transaction TXID unknown
08 = Invalid command code
09 = Scanner out of buffers
10 = Other client/server transaction in progress
11 = Could not connect to slave device
12 = Response data too large for block
13 = Invalid port
14 = Invalid size specified
15 = Connection busy
16 – 255 = Reserved
TXID (Most Significant Byte)
The transaction ID is a 1-byte integer in word 31 with a range of 1 to 255. It is
assigned in the ladder logic program when the processor creates and
downloads a request to the scanner. The scanner uses it to track the
transaction to completion. It returns this value with the response that matches
the request downloaded by the processor.
1 Size (Least Significant Byte)
The size of the service data is in bytes. The service data includes words used
for the response data. The maximum size is 58 bytes (29 words).
Port (Most Significant Byte)
The port that is used by the message is always zero (Channel A) on an SLC
scanner. It is zero (Channel A) or one (Channel B) for a PLC scanner.
2 Address (Least Significant Byte)
The node address of the slave device to which the transaction is sent. For the
Explicit Message to be successful, the slave device must be in the scanlist of
the scanner, and it must be online.
Service (Most Significant Byte)
If the message was successful, 0x80 is added to the service. If it is
unsuccessful, 0x94 is returned.
3 – 31 Response Data
This is data used for the message. For example, it may be the value read from a
parameter.