Sending messages – Rockwell Automation 5720 DriveLogix System User Manual
Page 129
Publication 20D-UM002C-EN-P - November 2003
Communicating with Devices on an EtherNet/IP Link 6-13
Sending Messages
The DriveLogix controller can send MSG instructions to other controllers
over an EtherNet/IP link. Each MSG instruction requires you to specify a
target and an address within the target. The number of messages that a device
can support depends on the type of message and the type of device:
MSG instructions are unscheduled. The type of MSG determines whether or
not it requires a connection. If the MSG instruction requires a connection, it
opens the needed connection when it is executed. You can configure the MSG
instruction to keep the connection open (cache) or to close it after sending the
message.
This device:
Support this many
unconnected messages:
Support this many
connected messages:
1756-ENBT module
(for a Logix5550 controller)
256
128
1788-ENBT daughtercard
(for a DriveLogix controller)
5
32
1794-AENT adapter
(for FLEX I/O)
The 1794-AENT adapter can support a total of 32 messages whether they be
connected, unconnected or some combination of both.
Ethernet PLC-5 controller
32
128
This type of message:
And this communication method:
Uses a connection:
CIP data table read or write
X
PLC2, PLC3, PLC5, or SLC (all types)
CIP
CIP with Source ID
DH+
X
CIP generic
CIP
Optional
(1)
block-transfer read or write
X
(1)
You can connect CIP generic messages, but for most applications, we recommend you leave CIP generic messages unconnected.