Rockwell Automation 1761-NET-DNI DeviceNet Interface (DNI) - Manual (Page 75)

Publication 1761-UM005B-EN-P - October 2006
Application Examples 75
DNI I-O.RSS Ladder 6 - COS ML DNI
0000
NEQ
Not Equal
Source A
I:0.0
341<
Source B
N7:89
341<
NEQ
Not Equal
Source A
I:0.1
0<
Source B
N7:80
0<
B3:31
11
0001
N7:82
13
B3:31
11
T4:38
DN
N7:82
8
0002 EN
DN
ER
Read/Write Message
Read/Write
Write
Target Device 485CIF
Control Block N7:82
Control Block Length 7
Setup Screen
MSG
This rung checks to see if the input data has changed from the previous ladder scan. If the input data has changed, bit
B3:31 is set.
MicroLogix 1000 Inputs Input Data has Changed Flag
The Time Out bit (TO) associated with each message instruction is used to clear the controller’s communications buffer and
message instruction. Setting the TO bit places the controller’s communication section in the same condition as when the
controller powers up. This rung detects if a message instruction is currently being processed and, when input data
changes, the existing message is terminated allowing a new transmission to start. It also terminates the message if the
message instruction does not complete (T4:38/DN).
MicroLogix to DNI Message Input Data has Changed Flag MicroLogix to DNI Message Timeout
Retry Message
This is the message instruction that writes data to the DNI. It is recommended that you use 485CIF as the target device. CIF
is the most efficient type of communications. This message instruction also has a destination address of 254. This value is
entered into the Setup Screen area of the message instruction.