Rockwell Automation 20-COMM-Q ControlNet Adapter - Manual (Page 168)

6-40 Using Explicit Messaging
20-COMM-C/Q ControlNet Adapter User Manual
Publication 20COMM-UM003F-EN-P
SLC 500 Controller
Examples The CIP messaging method provides two ways to perform explicit
messaging:
• Read/Write Parameter Service simplifies setup by requiring less data to
be entered in message configuration screens. However, the Read/Write
Parameter Service can only be used to perform single parameter read or
single parameter write explicit messages. (Multiple parameter reads or
writes must be performed using the Generic Get/Set Attribute Service
described below.)
Important: When performing a Write Parameter message, the data will
always be written to the drive’s Nonvolatile Storage (NVS).
Continuous NVS writes may damage the drive’s EEPROM.
If continuous writes are necessary, use the Generic Set
Attribute Single Service and attribute 10 (see
page 6-51 ).
• Generic Get/Set Attribute Service requires more setup data to be entered
in message configuration screens, but can be used to perform single
parameter read or write explicit messages or multiple parameter read or
write explicit messages. Also, the Generic Set Attribute Service offers
the choice of writing the data to the drive’s Nonvolatile Storage (NVS) or
the drive’s Random Access Memory (RAM; for Generic Set Attribute
Single service only, see
page 6-51 ). Note that when selecting the data to
be written to RAM, the data will be lost if the drive loses power.
For supported classes, instances, and attributes, see Appendix C ,
ControlNet Objects .
Block transfer or CEM (ControlNet Explicit Message) instructions can be
used to perform explicit messaging. Since CEM instructions are easier to
configure and perform more efficiently, they are used for these examples.
Important: RSLogix 500 software, version 7.10 or later, and a SLC 5/03,
SLC 5/04, or SLC 5/05 controller, Series C with firmware
version 10.00 or later, are required to use CEM instructions.