Rockwell Automation 1336-GM6 Enhanced DeviceNet Communications Module - Manual (Page 152)

F-14 Supported Emulated Block Transfer Commands
NVS Functions NVS (Non-Volatile Storage) Functions activates the specified NVS
functions.
PLC Block Transfer Emulation Instruction Data
PLC request instruction length: 4 words
Drive response instruction length: 3 words
Figure F.8
Message Structure
Message Operation
The NVS storage function allows three different message requests:
• NVS Save saves parameter information from the working
memory or RAM to NVS Storage.
• NVS Recall retrieves the last saved data from NVS Storage and
places it in the working memory or RAM.
• NVS Default Initialize clears the RAM and NVS Storage and sets
all parameter values to default.
If an error has occurred, response word 1 returns a value of -31998.
Example
This example requests the NVS Storage Save function be performed.
Data File Format
* Example only — These values vary depending on parameters and products.
Header
Word 0
PLC Decimal Value
–31998
Header
Word 1
Header
Word 2
PLC Request
Header Word 0
Header Word 1
Header Word 2
Message Length
Message Length
PLC Decimal Value
770 — Message OK
–31998 — Message Error
0
Drive Response
4
0
Data Word 3 NVS Command
Value NVS Command
00
01
02
03 Not Used
NVS Save
NVS Recall
NVS Default Initialize
3
0 1 2 3 4 5 6 7 8 9
PLC request 4 –31998 0* 0, 1, 2, or 3
Drive response 3 770 0*